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Michael Clive Price
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The Role of Enzymic Cofactors in Aging
or
How to Live to 200
Copyright 2002 Michael Clive Price Updated 18/10/2002
Feedback to michaelprice@ntlworld.com
Overview * Introduction * Anti-Aging Enzymic Cofactors *This monograph is about how to living long and healthily with supplementary B-vitamins and minerals. It explores the relationship between aging and the enzymic cofactors, derived from dietary B-vitamins and minerals. The hypothesis explored here is that many of the degenerative aspects of aging are due, in part, to dietary enzymic cofactor deficiencies. This aging-associated degeneration can be slowed or partly reversed with dietary supplements of the B-vitamins and minerals, meriting the description of anti-aging micronutrients.
To live longer we know we should cut down on tobacco, alcohol and calories, drink water75 and drive carefully. Less well known are the benefits of various micronutrients in our diet: micronutrients such as the B-vitamins, minerals and other dietary precursors to enzymic cofactors; yet the health and longevity benefits of the cofactor-yielding B-vitamins and minerals are much greater than the more widely publicised anti-oxidants, such as vitamins C and E.
We survey the dietary cofactors that have extended lifespan in animals, apparently by slowing aging1-6. We examine the experimental methodologies used and their relevance to, and implications for, humans. We examine a number of theories of aging in relation to various dietary-derived enzymic cofactors. In the light of the role of enzymic cofactors in aging we look to see what other dietary micronutrients may slow aging, or at least improve health. Finally we examine some prevalent misconceptions before concluding.
Any anti-aging micronutrient will extend lifespan, by definition, but lifespan experiments on humans will only be completed long after we are dead, so we must, in the meantime, look to animal lifespan experiments for guidance. Raising the dietary levels of cofactor precursors does indeed extend lifespan in a range of animals1-6, suggesting that the dietary cofactor precursors are anti-aging micronutrients. Most longevity experiments on mammals are done on rodents (rats or mice); lifespan experiments on insects tend to be done on fruit flies. In each case, to qualify here as anti-aging, the life-extending cofactors have to have been tested against a control group of animals receiving a normal diet, comparable to our modern diet. That is to say, the control diet was already sufficiently enriched to prevent any frank or overt vitamin or mineral deficiency diseases.
Table 1 lists the anti-aging effects on lifespan of some dietary cofactors,
Table 1 - Proven Anti-Aging Micronutrients
|
Cofactors |
Mean average lifespan increase in fruit flies |
Mean (Max) lifespan increase in rodents |
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B3 (niacin) |
15% 4 |
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B5 (pantothenate) |
27.8% 1a |
19.5% 3 |
|
B6 (pyridoxine) |
10.5% 1b |
>11% 6 |
|
B7 (biotin) |
0% 1b |
|
|
RNA |
11.3% 1b |
16% (8-16%)2b |
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B6 + B7 + RNA |
20.3% 1b |
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|
B6 + B7 + RNA + B5 |
46.6% 1b |
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|
Chromium |
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27% (26%) 5 |
g = gram, mg = milligram, ug = microgram
Note: Empty cells indicate no data available, not a zero or a null result. Maximum lifespan data is in brackets, ().
Let’s examine the methodologies and results:
As a measure of lifespan extension I have used both the mean average and maximum lifespan of the experimental animals (or cohort), relative to the controls, known as the cohort mean and maximum lifespan, respectively.
Cohort maximum lifespans – if measured by the age of the last survivor - are subject to high random scatter or uncertainty, since only one animal defines the maximum age from a relatively small group. A better measure of maximum lifespan is the mean average lifespan of the longest-lived 10% of the cohort.
An anti-aging intervention should increase maximum lifespan; extending the survival curve, is generally interpreted as a sign of retarding the aging process33. Unfortunately maximum lifespan data are less frequently reported than mean average lifespan data, but the mean lifespan increases are, in both reported cases2, 5, comparable to the maximum lifespan increases, expressed as percentages. Any micronutrient with a prophylactic across a broad range of degenerative diseases, e.g. prevented or slowed neurological decline, cancer and cardiovascular disease, and which also extends mean lifespan, I would expect to extend maximum lifespan by a similar amount: i.e. have an anti-aging effect. I exclude any micronutrient from being anti-aging if it only acts across a limited range of degenerative diseases (e.g. selenium). All the micronutrients in the anti-aging table qualify as anti-aging by these criteria.
Rodents and fruit flies are very dissimilar creatures, with their last common ancestor living prior to the Cambrian Explosion, about 670 million years ago30, yet, despite this, mammals and insects share most of the same fundamental metabolic pathways, including their dependency on the same basic B-vitamin-derived coenzymes84. Only the plants and some single-celled organisms (e.g. prokaryotes, including bacteria) can synthesise these coenzymes from scratch. All animal life, from insects to mammals, depends on life lower down in the food chain to source their B-vitamins and derivative coenzymes; all animals share the same dietary dependency upon B-vitamins84. This is not true for some of the other vitamins, for instance vitamin C, for which substantial differences exist in the biosynthesis of, and requirement for, between different branches of animal kingdom.
Comparing the life extension percentages for the rodents and fruit flies, for which we have comparable data (i.e. for vitamins B5 (pantothenate), B6 (pyridoxine) and dietary RNA) we find they are within approximately 40% of each other. This is remarkably good agreement, considering the absolute lifespan differences between the fruit-flies and rodents; the anti-aging action of these enzymic cofactors (which excludes chromium) must operate at a very basic level, common to all animals, and should extrapolate very well within mammals80, from rodents onto humans, with perhaps only a 6% intrinsic error, since humans are approximately 7 times more closely related to rodents than fruit flies31. Calorie restriction, another anti-aging intervention, extends the maximum lifespans of rodents and fruit flies by approximately the same factor33, which, again, suggests that the basic aging mechanisms in all animals are similar.
The health benefits to already healthy humans of supra-RDA levels of micronutrients - as demonstrated by many placebo-controlled trials47-61 and epidemiological studies11-14, a view finally endorsed in a JAMA review82 - are further circumstantial evidence that their anti-aging effects will extrapolate onto humans.
The life-extending, anti-aging effects of dietary RNA, B5 (pantothenate) & B6 (pyridoxine), in combination on insects, is approximately the sum of their effects separately1b, presumably because the derived enzymic cofactors can’t substitute for each other; each enzymic cofactor facilitates its own distinct metabolic action, independently of the other enzymic cofactors, even though their systemic effects are inter-related. We’ve already noted the apparent commonality of the operation of these enzymic cofactors on all animals; their anti-aging nature should additively119 extrapolate from insects on to rodents and humans.
This postulated anti-aging synergy119 between enzymic cofactors, in mammals, is rendered still more plausible by the demonstrated health synergy between various combinations of the vitamins B1 (thiamine)110d, B2 (riboflavin)100, 110, 113, 114, 115, B3 (niacin)43c, 55a, 110d, 111, 113, B5 (pantothenate)112, B6 (pyridoxine)11b, 43, 52c, 86, 110b-d, 113, 114, B7 (biotin)37d, 55d , B9 (folate)11b, 43a, 43b, 43d, 52, 53, 115, B12 (cobalamin)11b, 43a, 43c, 52a, 52b, 53, 112, C13, 100, 110d ,D100 & E13 , enzymic cofactors acetyl-L-carnitine37, alpha lipoic acid37a-c and the minerals chromium55a, 55d, zinc110a, 110b, 111, selenium45, calcium100 and magnesium45, 86.
Adding up the mean average life extension percentages from B3 (niacin), B5 (pantothenate), B6 (pyridoxine), dietary RNA and, after adjustment, chromium we get an approximate 66% mean lifespan extension. If we assume that humans in modern affluent society are as cosseted as laboratory animals then, it implies that the modern human average lifespan of approximately 75 years is extendable to over 120 years, by dietary intervention alone, with a commensurate maximum life span increase from 122 to over 200 years.
Developmental or programmed theories of aging, in which growing old was regarded as similar to growing up, controlled by biological switches and hormones, used to be popular. Gerontologists searched for "death hormones" and experimented with monkey-gland transplants, and such like, in futile attempts at rejuvenation. But if ageing were a developmental process then we’d expect to see some aging-arrested individuals (immortals), just as we see developmentally-arrested individuals94. Later "rates of living" theories were formulated, where lifespan was limited by total lifetime metabolic expenditure or number of heartbeats. These attempts have all failed28a, 121.
With an increasing awareness of evolution and the "selfish gene" concept28b, aging has come to be regarded as a side-effect of evolution’s focus on our genes, with our bodies (soma) acting as disposable genetic transmitters or conveyers of the germ line to the next generation. According to the "disposable soma" theory of aging28c, aging is a simply a reflection of the low priority evolution assigns to our individual survival, once we (or close relatives) have successfully reproduced. Evolution hasn’t programmed us to grow old and die; aging is just a side effect of not being perfectly constructed for individual immortality. Evolution has designed us with enough built-in redundancy and repair mechanisms to see us past reproduction and child rearing, after which we decline, not through design or malice, but simply by evolutionary indifference; there is no master aging switch, no death hormones; aging is a multifactorial process, with no single cause. No single mechanism, such as telomeres, loss of redundancy, mitochondrial dysfunction, genetic degradation, glycation, free-radical damage is going to be the complete answer. Rather, during aging all the above factors, plus a lot more we can’t even guess at, at the moment, degrade all aspects of our metabolism, in a vicious circle, putting us on a downward spiral towards complete homoeostatic breakdown, called death.
The hypothesis advanced here is that aging is largely the progressive breakdown of metabolic homeostasis, coupled with the erosion of built-in redundancies (of various forms), for a variety of reasons, known and unknown. Enhancing the performance of our enzymic control systems may delay this downward spiral. Enzymes depend critically on the presence of coenzymes and other enzymic cofactors (see Glossary and Appendix A for details) and the lifespan experiments indicate a chronic general sub-clinical enzymic cofactor deficiency. Correcting various enzymic cofactor deficiencies may slow this metabolic degradation, improve our health and prolong life.
We shall now examine some of the postulated causes of aging and see how they relate to the various dietary enzymic cofactors.
Methylation19, the transfer of methyl groups (CH3) in metabolic reactions, is vital for many aspects of life. All methylation is effected by the coenzyme, SAMe, with the exception of the methylation reaction that regenerates SAMe itself from homocysteine via methionine which requires methylcobalamin. Optimal methylation is essential for preventing neurological decline, cancer and cardiovascular disease.
Every time a cell divides errors may creep into the daughter cells’ DNA, leading, eventually, to cancer, which is why body tissues subject to a lot of cell replication (such as the lining of the colon) are prone to develop cancer; errors (mutations) are introduced into the DNA by the associated DNA copying process. Methylation protects against DNA transcription errors during cell division25, 18. Long-term folate supplementation is particularly effective against colon cancer in humans11, 41e. Breast cancer, which is principally caused by hormonally triggered cell division, has a reduced incidence in high-folate consumers97. If the protective effect of folate is due, as hypothesised, to reducing the DNA transcription errors and maintaining genomic stability18 then it should also be effective, to some degree, against most cancers17, and would nicely compliment the DNA repair effect boosted by NAD, a vitamin B3 (niacin) derivative (see section on Nuclear DNA: Damage and Repair).
SAMe production is sensitive to dietary intakes of zinc, B9 (folate), B6 (pyridoxine) and B12 (cobalamin)11a, 25, 18, and, for approximately 10-15% of people, B2 (riboflavin).115, 124 Maintaining high levels of SAMe keeps homocysteine levels low which, in turn, is critical for maintaining cardiovascular health19.
Summary: Ensuing adequate methylation, with the B vitamins B6 (pyridoxine), B9 (folate) and B12 (cobalamin), protects against a range of age-related disorders, in particular cardiovascular disease and some cancers, and can be regarded as being anti-aging.
Beyond Methylation; the Enzymic Cofactor Hypothesis
Methylation is just one of the many vital metabolic transformations mediated by coenzymes, in this case the coenzyme SAMe. Some of the other coenzyme mediated transfer reactions include acetylation, carboxylation, glycosylation and oxidation-reduction reactions involving both 1- and 2-electron transfers in both the aqueous and lipid soluble cellular compartments. (See Appendix A for more complete list.)
Amongst all the coenzyme mediated reactions available there is no reason to suppose that methylation occupies a privileged role. Enhancing methylation is believed to slow aging, delaying the onset of degenerative disorders19; perhaps enhancing the other coenzyme-mediated reactions would be similarly beneficial to fighting aging. This is this monograph’s aging and enzymic cofactor hypothesis. Methylation is an example of a one particular aspect of the broader coenzyme or enzymic cofactor hypothesis; many of the degenerative aspects of aging are due, in part, to dietary enzymic cofactor deficiencies and their consequent metabolic dysfunctions. Most of the body’s coenzymes are sourced from dietary RNA and the B-vitamins; minerals supply additional enzymic cofactors. These micronutrients are vital in maintaining metabolic homeostasis, optimum function and slowing aging.
In the previous section on methylation we tacitly assumed that the cardiovascular and anti-carcinogenic health benefits of the B-vitamins B6 (pyridoxine), B9 (folate) & B12 (cobalamin) were due to their methylation-enhancing properties, via the coenzyme SAMe. But it is equally likely, at the very least, that the coenzyme optimising activities of these three B-vitamins are partially SAMe-independent. For instance, the low levels of the same three B-vitamins are associated with Alzheimer’s dementia,41 independently of their methylation-related and homocysteine-lowering effect.79 Intervention trials with B1 (thiamine)106a-c, B9 (folate) 107, B12 (cobalamin)104 , acetyl-L-carnitine105 (precursor to coenzyme carnitine) and alpha lipoic acid98 (precursor to coenzyme lipoamide) have all shown success, to varying degrees, in stabilising the progression (and presumably prevention also) of Alzheimer’s and other forms of dementia106d. In general the benefit is greatest with early intervention104b, 104c, 107 and in young victims105f, 105g.
Summary: As with methylation, it is likely that the many other reactions mediated by coenzymes, mostly derived from dietary RNA, B-vitamins and minerals, will be critical for metabolic homeostasis, slowing aging and maintaining health.
Glycation is the non-enzymic binding of glucose molecules to other molecules in general. This binding is uncontrolled and destructive, causing the faster aging exhibited by diabetics, and, since as we age we all tend to become pre-diabetic55, 83i (with reduced glucose tolerance, rising insulin and increased insulin-resistance and glucose levels), it is implicated in normal aging83.
Chromium, one of the anti-aging minerals, is implicated in glycation. Animals fed chromium (as chromium picolinate and other forms) have lower fasting glucose and insulin levels and improved glucose tolerance. A range of studies on pigs, dogs and rodents suggest that glucose processing is optimised when the chromium intake in ug is above 1/5 of the number of calories consumed5d. In humans, chromium benefits both the healthy non-diabetics55 and diabetics, types 110d & 210, by improving the lipid profile, lowering insulin levels, fasting glucose levels and improving glucose tolerance. Both vitamins B3 (niacin)55a and high-dose B7 (biotin)55d synergise with chromium in improving insulin-resistance.
Part of the reason why chromium deficiency is so common is that plants do not require chromium, like selenium; plants can thrive in chromium poor soils, leading to chromium poor diets. Chromium optimises insulin function, which, in turn, lowers fasting glucose levels, improves glucose tolerance and reduces glycation. Chromium’s anti-glycation, glucose-regulatory action is mediated entirely via the protein insulin (a hormone); chromium, therefore, is a proteonomic cofactor with a single target protein, unlike the enzymic cofactors, which, typically, operate in conjunction with number of target enzymes. Therefore we have to be cautious in extrapolating the chromium rodent lifespan extension of 27% to humans; the control rats tested showed evidence of pre-diabetic, sub-clinical insulin resistance – their glycated haemoglobin levels increased almost 4-fold more as they aged5a, 5c (as a proportion of their lifespan) than in non-diabetic humans83i; the anti-aging effect on non-diabetic humans will probably be only a quarter as much, about 7%.
Independently of any synergy with chromium, vitamins B1 (thiamine)88c-e, B3 (niacin)85, B6 (pyridoxine)88a-e, and B7 (biotin)93 along with minerals magnesium, zinc91, in doses greater than the RDA, improve insulin-resistance and lower glycation levels.
Calorie restriction (see later) also lowers glycation and extends lifespan, but whether it will synergise with the above micronutrients is unknown.
Summary: chromium, magnesium and zinc, along with vitamins B1 (thiamine), B3 (niacin), B6 (pyridoxine) and B7 (biotin), are effective in preventing or ameliorating diabetes and, even in non-diabetics, reducing glycation levels and slowing aging.
Using the aging and enzymic cofactor hypothesis we can explain the benefit of dietary RNA. During digestion RNA is broken down into, and absorbed as, nucleotides and nucleosides. Nucleotides and nucleosides have a direct metabolic action, independent of their role in RNA, and are precursors to a number of coenzymes. The energy-supplying coenzyme ATP is a nucleotide, for instance, critical to our metabolism. There are other nucleotide coenzymes, such as UDP and CDP, required for biosynthesis of glycosaminoglycans, lipids and glycogen. (NAD and CoA are also nucleotide coenzymes, but are not derived from dietary nucleic acids.) Ribozymes, enzymes constructed from nucleotides instead of amino acids, are another example of the role of nucleotides.
RNA has a high turnover, being required for all gene expression and protein synthesis. We are capable of synthesising nucleotides from scratch (via the de novo pathways) but this is very expensive, in terms of the energy required. To ease the burden of de novo synthesis we have evolved the so-called salvage pathways which process nucleotides & nucleosides available both from our diet and from the natural turnover and breakdown of cellular RNA.
The amount of RNA in foodstuffs varies widely. Sardines, one of the most RNA rich foods, are between 0.5% – 1% by weight. To ingest the 250mg of RNA required for the life extension effect, we need only eat 12 – 25 g of sardines per day.
Summary: RNA enriched diets are beneficial to health, and in particular the immune system24, 26, 60, 61, and have extended lifespan1, 2.
Nuclear DNA: Damage and Repair
As we age our DNA degrades. Since our DNA encodes genes for the structures of all our proteins, including enzymes, maintaining genomic stability is critical for staving off age-related degradation95. Radiation, free-radicals, glycation and our own imperfect DNA copying mechanisms, all contribute to DNA damage (mutations) building up, chromosomal breaks, gene mal-expression, expression of defective proteins, including malfunctioning enzymes. As with all aspects of aging, it is difficult to separate cause and effect. Is DNA damage the cause of aging or just an effect? Probably both, since animals exposed to DNA damaging radiation show signs of accelerated aging, in addition getting more cancer.
DNA is a double stranded molecule, with the genetic information duplicated on both strands. If the damage is confined to one of the strands then it can be repaired by the base excision-repair mechanisms. Enzymes remove the damaged sections of DNA from one strand (excision) and then rebuild (repair) the lost sections of the strand, using the other strand as a template. One of the enzymes involved in this generalised DNA base excision repair process (BER) is poly(ADP-ribose) polymerase, or PARP, which produces a repeating poly(ADP-ribose) polymer sequence for integration into the repaired DNA. PARP requires nicotinamide adenine dinucleotide (NAD) as a substrate, and is very sensitive to NAD concentrations, as shown by an experiment in which rodents exhibit increased resistance to UV-induced cancer when fed a diet rich in vitamin B3 (niacin), which elevated cellular NAD levels by a factor of 3 or so27c. Vitamin B3 (niacin) is a precursor to the coenzymes NAD and NAD-phosphate (NADP). Although not strictly a vitamin - our bodies can produce NAD/NADP from dietary tryptophan - it functions like one since this production is not very efficient. Dietary consumption of niacin elevates NAD tissue concentration, in animals and humans27d, 27e, which up-regulates the activity of PARP, increasing the DNA repair efficiency and reducing the induced27c, 27f cancer rate and lowering over-all long-term human mortality27g. Similar cancer prevention is expected in humans, who are typically more NAD deficient than many animals27d.
Magnesium ions are essential for the operation of kinases, enzymes that use a magnesium-ATP complex as a phosphoryl-group donating substrate, and are critical in maintaining genomic stability38d. Magnesium deficient animals show signs of premature aging38b-d. In humans magnesium has been successfully used to treat kidney stones, high blood pressure, migraine, coronary artery spasm, irregular heart rhythms and diabetes. Levels of magnesium in drinking water correlates with longevity via decreased cardiovascular disease38a. Most people are magnesium deficient; their diets don't even supply the RDA of magnesium; it seems sensible to supplement with magnesium to stave off premature aging. Magnesium synergises well with vitamin B6 (pyridoxine).86
The ability of selenium15, 16, 54, 72 to reduce cancer incidence suggests the selenoenzymes may also provide some genomic protection.
Summary: Vitamin B3 (niacin), the NAD precursor, can provide considerable protection against DNA damage generally. Since almost all adult cancers are the result of DNA damage then this may prevent many cancers. Magnesium and selenium are also be important for genomic stability. If DNA damage is implicated in aging then magnesium and vitamin B3 (niacin) may be essential to help ward off premature aging.
Our cells have two centres of DNA, the nucleus and the mitochondria. Experiments with fruit flies suggest that the mitochondrial DNA is more important to aging than nuclear DNA46
Mitochondria are sub-cellular organelles possessed by all nucleated cells. The mitochondria multiply independently of their host cell and possess their own DNA. Once upon a time, perhaps a billion or so years ago, the mitochondrial ancestors were independent free-swimming organisms that evolved the unique ability to process oxygen to generate bio-energy, which we call respiration. Some of them formed a productive symbiotic relationship with other cellular life, where, today, the mitochondria act as powerhouses to their hosts. The extra energy available to these symbiotics enabled them to go on to form all the complex multicellular organisms, such as animals, plants and fungi. (The ancestor of all plants subsequently acquired chloroplasts for photosynthesis, in a similar fashion.) Unfortunately respiration with oxygen also produces free-radicals (or, in this context, reactive oxygen species or ROS), which are harmful. As we age our mitochondrial DNA degrades, presumably due to ROS-induced damage, and the efficiency of the mitochondria decline. Experiments with fruitflies have shown that longevity is transmitted by the mitochondrial DNA (which is inherited maternally) and correlates negatively with ROS production46.
Transport of the respiratory substrates into the mitochondria requires the enzymes carnitine acyltransferase I & II, and co-enzyme A from B5 (pantothenate)). Feeding old rats with diets rich in carnitine and/or alpha-lipoic acid (both enzymic cofactor pre-cursors) reversed many aspects of age-related mitochondrial decline37a, 37b, including lowering ROS production37c, although lifespan results are not yet available. The benefits of carnitine may synergise with biotin37d.
Mitochondrial DNA shares with nuclear DNA the same base excision repair (BER) pathways.123a, 123b If mitochondrial DNA BER has the same dependency on PARP and NAD as the nuclear DNA BER then B3 (nicotinamide) should protect mitochondrial DNA in a similar fashion to nuclear DNA. This might explain why feeding fruitflies B3 (nicotinamide) lowered ROS production and extended their lifespans4 and, in humans, has lowered long-term mortality.27g
Dietary B4 (choline), supplied as lecithin (phosphatidylcholine), to rats, protects some mitochondrial DNA from age-related degradation.125
Many other coenzymes are involved in mitochondrial metabolism.
Summary: Carnitine, vitamins B3 (niacin), B4 (choline), B5 (pantothenate) and alpha-lipoic acid are effective at maintaining or even rejuvenating mitochondrial function.
The free-radical theory of aging was started in the 1950s and popularised in the 1970s & 1980s109. Free-radicals possess unpaired electrons, bonding with neighbouring molecules in an uncontrolled fashion, causing permanent unwanted bonds between molecules (cross-links) and damaging DNA. Many metabolic reactions produce free-radicals, particularly oxidation-reduction reactions. Free-radicals probably contribute to aging, but the extent of their contribution is debatable. Attempts to demonstrate the life-extension properties of vitamin C & E, given singly, have failed, although they do seem to improve cardiovascular health and, to a lesser extent prevent cancer, lowering age-related mortality rates when taken in combination13, 14.
Antioxidants are substances that mop up the free-radicals. Vitamins C & E are antioxidants. The B-vitamins and minerals are not antioxidants, although they can produce an antioxidant effect by boosting the action of our antioxidant enzymes. Some of our antioxidant enzymes are catalase (which break down hydrogen peroxide, H2O2 to H2O and O2) & glutathione peroxidase (converts hydroperoxide, R-O-OH to ROH), superoxide dismutase (which combines the superoxide radical, O2- with H+ to form H2O2 and O2). Any enzymic cofactors that boost the activity of these enzymes have an indirect antioxidant effect. Zinc, copper and manganese, for instance, are required for the various forms of superoxide dismutase. Zinc supplements reduce post exercise free-radical activity90. Vitamin B6 (pyridoxine) is required for the synthesis of all enzymes, anti-oxidant or not, and other proteins.
Selenium is required for the production of the antioxidant enzyme glutathione peroxidase. Supplementation with selenium has shown remarkable benefits in reducing cancer rates15, 54, 72 and overall mortality. Trials on humans with 200ug/d for just 5 years halved the cancer mortality and reduced over-all mortality15. Other human epidemiological studies, which show lower rates of cancer and cardiovascular disease in areas and countries with high selenium intake, suggest that zero cancer incidences may be achievable at approximately 400ug/d16. It’s worth noting that it is very hard to get this amount from a diet – supplements may be safer since the dosage is easier to control. Part of the reason why selenium deficiency is so common is that selenium, like chromium, is only minimally required by plants23b; plants can thrive in selenium poor soils, leading to selenium poor diets. Brazil nuts, for instance, which are popular as a dietary source of selenium, may vary by a factor of 10,000 or so in their selenium content23a, which, considering that a few milligrams may be toxic72a, 73, means that you risk either deficiency or overdosing by relying on diet alone as a source of selenium.
Free-radicals, although injurious to health, may not be involved in aging. The selenium trial15, which halved cancer mortality, did not reduce other causes of death. This suggests that free-radicals, or at least hydroperoxide ions, whilst they contribute to cancer, do not contribute to aging. And indeed whilst selenium33a improves the survival curve it does not extend it, i.e. cohort mean average lifespan was extended, but not maximum lifespan. Maximum lifespan was also not affected by another free-radical scavenger, vitamin E122. This is what we might expect from nutrients with a limited range of action, as previously discussed. Additionally, elevated levels of the antioxidant enzyme superoxide dismutase failed to extend lifespan in mice92. On the other hand curcumin7, an antioxidant with anti-carcinogenic properties, has extended maximum as well as mean lifespan, although this may to due to curcumin’s non-antioxidant behaviour.
Oxidative damage and free-radicals, whilst not implicated strongly in aging, are causative for a number of degenerative conditions, such as lipofuscin accumulation, in post-mitotic cells. Vitamin E, a free-radical scavenger, is effective against lipofuscin accumulation116a-c, 116f, which may be reversible116c, 116d. Any anti-oxidant strategy would be expected to slow the progression of this and other oxidative-induced conditions; micronutrients such as vitamin B6 (pyridoxine)116e and the minerals selenium (and perhaps zinc and curcumin) should be helpful.
Summary: Vitamin B6 (pyridoxine) and E and the minerals selenium and zinc (and perhaps copper, manganese and curcumin) are important for optimal antioxidant enzyme function, although the role of antioxidants in aging is unclear.
Redundancy versus Regeneration
Reliability theory87, originally an engineering concept, basically says that any complex, reliable system requires redundancy in its irreplaceable elements to operate. Evolution has given us both an imperfect set of repair mechanisms and some redundancy, in differing amounts in our various sub-systems and organs, as the most cost-effective way of prolonging our lives, according to the dictates of disposable soma. The marginal cost of the extra redundancy is balanced by the extra cost involved in developing more efficient repair mechanisms. This is a trade-off. Organs that regenerate very well (e.g. liver) have no need for redundant spare capacity (beyond their generic telomeric redundancy), whereas organs that regenerate very poorly (e.g. kidneys and brain) have lots of spare capacity.
Our kidneys have almost no regenerative capacity; renal capacity declines with age. To compensate evolution gives a large amount of back-up, spare capacity, so that in our youth between 75%-90% of our kidney or renal function is redundant. If we live long enough, chronic renal failure will eventually kill us, progressive damage being inflicted by glycation and vascular dysfunction, amongst other causes. The earlier in life anti-glycation and vascular protective measures are started, such as extra dietary chromium10, 55a-c and vitamins B1 (thiamine)88d, 88e, B3 (niacin)55a, B6 (pyridoxine)19, 88, B7 (biotin)55d, B9 (folate)19 and B12 (cobalamin) 19 the longer our renal redundancy will last.
Some regions of our brains have a similar degree of redundancy. Parkinson’s disease is characterised by massive degeneration and loss (up to 98%117g) of dopaminergic substantia nigral neurons117h. This loss is at least partially driven by oxidative damage and can be slowed by anti-oxidant intervention. Anti-oxidants demonstrated to slow the progression of Parkinson’s include melatonin 117a, 117b, vitamin D3117e and E117d, and flavonoids117f with a high probability that alpha lipoic acid and carnitine would provide additional mitochondrial support37a, 37b, 117c along with other anti-oxidant micronutrients such as vitamin B6 (pyridoxine) and the mineral selenium (and perhaps zinc and curcumin). Anti-glycation measures, with vitamin B6 (again), chromium, and B7 (biotin) may also slow the progression of Parkinson’s.
Another type of redundancy is our genetic redundancy against cancer. Genetic damage is at the root of almost all adult cancers17 - a cancerous cell being the end product of a chain of approximately 5 independent mutations9. This represents genetic redundancy against cancer, which we erode every time one of the critical pre-cancerous genes is damaged and not repaired. The effects of stopping smoking neatly illustrate the difference between regenerative and redundant components. A smoker has an increased risk (relative to a non-smoker) of the two main killers of old age: cardiovascular disease (stroke, heart attack) and cancer. Within a few years of stopping smoking the ex-smoker's cardiovascular risk is pretty much the same as if they had never smoked78d-f. The risk of cancer, though, always remains substantially elevated78a-d; our cardiovascular system is capable of rejuvenation, whereas our genome is not; irreversible genetic damage or mutations accumulate at a fairly steady rate past the age of 20 years9. As we age we irreversibly lose the genetic redundancy we are born with. Eventually cells turn cancerous. This suggests that we can rejuvenate our cardiovascular system by taking micronutrients, but that we but we can only retard further damage and deterioration to our genome, not reverse it. Genomic protection strategies, such as vitamins B3 (niacin) 27c, 27d, 27f, 72b, B6 (pyridoxine)11b, 19, B9 (folate) 11, 18, 25, 53, B12 (cobalamin)11b, 18, 41e, 53, selenium54, 72 and magnesium38b-d, need to be implemented whilst we are still young for maximum, long-term, protective effect.
In all cases, though, intervention strategies can only slow the irreplaceable loss of redundant spare capacity. The earlier any interventions are started the longer the redundancy will sustain us. This is almost certainly why the life-extension effect of supplements is diminished the later in life they are started. With dietary RNA2a, for example, when the supplementation was started in old age (approximately equivalent to 60 human years) then there was a 9% mean life extension, as measured against the controls' total mean lifespan, whereas for the whole-life supplemented mice there was a 16% mean life extension. This suggests that extra dietary RNA not only retarded but also actually reversed some of the aspects of aging - i.e. partial rejuvenation was achieved. Another micronutrient, curcumin, induced an 11% lifespan extension when started in mid-life (approximately equivalent to 35 human years), but only produced 3% lifespan extension when started later (approximately equivalent to 50 human years)7, implying aging retardation but not rejuvenation.
Summary: don’t wait until too late.
Telomeres are another example of genetic redundancy. Telomeres are repeating sequences of DNA at the end of chromosomes. In humans, but not all animals, as cells divide their telomeres shorten, which is why children have longer telomeres, on average, than adults. Eventually, after sufficient cell divisions, as telomeres become too short the cells reach the Hayflick63b limit, cease dividing (replicative senescence) or even die (apoptosis)63a. Some of our tissues, e.g. skin, bone marrow and gut, which require constant cell division, express an enzyme, telomerase (an example of a ribozyme), which lengthens telomeres, enabling constant tissue proliferation throughout life. Telomerase expression is usually switched on in cancer cells; inappropriate over-expression of telomerase being one of the critical mutations a cancer cell requires to replicate unchecked.
Telomere length represents the trade-off between tumour-suppression and tissue-repair62c. Short telomeres enhance tumour suppression, but with an earlier replicative senescence shutdown at a reduced Hayflick limit. Long telomeres allow more extensive and later tissue proliferation, along with greater reproductive time-spans, but with an increased risk of tumours.
One of the theories of aging is that telomere shortening drives the aging process, by limiting the number of cell divisions available for tissue repair. On one hand over-expression of p53 (a gene which telomeres use to induce replicative senescence or cell death (apoptosis)) accelerates the appearance of aging and shortens longevity64a, 64b. On the other hand telomeres don’t shorten in rodents62d, yet rodents seem to age in the same way as humans, albeit faster. Also, amongst mouse strains, there is no correlation between lifespan and telomere length62a. Finally, amongst primates, humans have the longest lifespans, yet the shortest telomeres62b. So, again, it seems unlikely that telomeres directly determine lifespan. It is more likely that telomeres primarily function to protect us from cancer. Amongst the primates, perhaps our short telomeres reflect the higher level of anti-cancer protection required for longer-lived humans?
Another factor to consider is that telomere shortening may not be driven just by cell division. There is some evidence that telomere shortening is partially oxidatively driven63c-e, independently of cell division; reducing and combating cellular stress, by maintaining adequate coenzyme levels, will not only slow the rate of cell division (through lowering the requirement for damaged tissue repair and proliferation) but may actually extend the number of cell divisions permitted before the Hayflick limit is reached. Livers subjected to the stress of long-term chronic hepatitis or cirrhosis exhibit accelerated telomere shortening63f. Low levels of PARP (poly(ADP-ribose) polymerase), which can be up-regulated by dietary vitamin B3 (niacin) 27c, 27d, 27e, causes accelerated telomere shortening and genomic instability in mice.126 This suggests (but does not prove) that B3 (niacin) may slow telomeric shortening, at least in some circumstances, extending tissue replicative potential.
Summary: telomeres govern the replicative lifespan of cells and the long-term regenerative ability of tissues and organs, but their role in aging is unclear. In any event B3 (niacin) along with general anti-oxidants may be helpful in extending our telomeric redundancy. By looking after our health, we can slow telomeric shortening and extend our tissue’s regenerative potential and operating lifespan.
Probable Anti-Aging Enzymic Cofactors
The B vitamins B5 (pantothenate) and B6 (pyridoxine) have extended mammalian lifespan; B3 (niacin), B9 (folate) & B12 (cobalamin) are proven health boosters; it is worth considering supplementing with all the B-vitamins. Collecting together the range of B-vitamins and minerals which haven't been tested for their lifespan extending effect, on mammals, but which have demonstrated considerable health benefits in humans, and across a broad enough set of measures to be consider potentially anti-aging, we have:
B2 (riboflavin), B9 (folate) and B12 (cobalamin) are critical for adequate methylation11a, 18 ,25 ,115, 124. B3 (niacin) has extended lifespan in insects4 and lowered long-term mortality27g in humans. If it passes the lifespan test then we would consider it an anti-aging micronutrient. B7 (biotin), is important in reducing glycation55d, 93 and hence aging, despite failing to extend insect lifespan in one experiment1b.
If magnesium exerts an anti-cancer effect via genomic stability, in addition to its cardio-vascular protective effect, then it to may be considered an anti-aging candidate38b-d. Zinc may have an indirect anti-glycation effect91, which makes it an anti-aging candidate.
Coenzyme Q10, carnitine and lipoamide (another coenzyme) are all synthesised internally, like SAMe, although normally in sub-optimal amounts. Co-Q10, lipoamide and carnitine look like promising life extenders32 in combination, if not singly. Carnitine and lipoamide separately, and even more so together, have rejuvenated old rodents, measured across multiple parameters37a-c, although CoQ10, given alone, increased ROS production4. Again it may be worthwhile taking the B-vitamins, C and minerals such as magnesium and zinc to boost CoQ10, carnitine and lipoamide’s biosynthesis, in a similar fashion to SAMe, before considering direct supplementation. For CoQ10 this makes especial sense, since our gut poorly absorbs it.
A defining and irritating drawback with this 2nd category of dietary enzymic cofactors is that we have no hard numerical data for calculating an expected lifespan extension effect. Statistically we might expect – in the Bayesian sense - the life extension /anti-aging effect of the probable anti-aging 9 enzymic cofactor-precursors (vitamins B1, B2, B7, B9, B12, magnesium, zinc, carnitine and alpha-lipoic acid; 16 cofactors) to be more than 66% yielded by the 5 known anti-aging cofactor-precursors (vitamins B3, B5, B6, RNA and chromium; 10 cofactors). (RNA is a precursor to 5 coenzymes; B2, B3 and B12 are precursors to 2 coenzymes each; the B9 (folate) form a class of 6 coenzymes.)
If all the probable anti-aging enzymic cofactors work as projected then an additional mean life extension of 66% *16/10 = 106% (i.e.172% extension in total) is expected, probabilistically speaking. In practice we must expect that some of the probable anti-aging cofactors will be duds; a more reasonable expectation is a total mean lifespan extension somewhere in the range of 66% to 172%. A doubling of our natural lifespan would be a reasonable expectation.
Health-boosting Micronutrients
Non-(enzymic cofactor) micronutrients may help square the survival curve, but they are unlikely to extend it as a true anti-aging micronutrient would. Most of the anti-oxidants (see previous discussion) I include in this category.
Vitamin C: hard to extrapolate anything from experiments on rodents, since nearly all non-primates mammals (e.g. rodents) synthesise ascorbic acid naturally. Primates, including humans and fruit bats, have lost the ability to synthesise ascorbic acid due to the high amounts in their fruit-rich diet. The average human ingests more than 2.5 g/day before increased excretion occurs, which suggests that our metabolic requirement for this vitamin is in the multi-gram /day range77. Vitamin C alone14, and in conjunction with vitamin E13, has reduced overall mortality rates in humans and would presumably raise average lifespan at least.
The synthesis of human growth hormone, melatonin & DHEA are all dependent on dietary enzymic cofactors. Rather than take these hormones directly – oral intake of each may have downsides22, 39a-c, 68a, 68c or simply be ineffective68b – it is possible to boost the body's own synthesis by supplementing with a range of their precursor cofactors, such as the B-vitamins and minerals. Chromium picolinate, for instance, has been shown to boost DHEA levels in the middle-aged and elderly20, 21. And boosting the body’s production of SAMe (the coenzyme responsible for all methylation reactions), with B6 (pyridoxine), B9 (folate) and B12 (cobalamin)118 also aids in the conversion of serotonin (a neurotransmitter) to melatonin.
Selenium is effective in reducing cancer rates15, 16, 54, 72, but may have too narrow a range of action to delay aging. Selenium’s anti-cancer, tumour suppression effect may be due to induced cancer cell death (apoptosis) via activation of the p53 gene64c, 64d, rather than genomic protection.
The carotenoids (e.g. alpha- & beta-carotene, lycopene) are naturally occurring pigments in plants which step down the harmful high frequency ultra-violet (UV) light to lower frequency, less harmful and more visible, wavelengths. Plants produce them to simultaneously utilise and protect against UV. By ingesting them we can also acquire partial protection from UV damage. Carotenoids are also anti-oxidants. Beta-carotene, for instance, is a quencher of singlet oxygen and free radicals, which may account for beta-carotene and lycopene preventing prostate70 and liver67 cancer. Their health benefits extend beyond their antioxidant properties, though. For instance lycopene actually inhibits the tumour growth and proliferation of prostate cancer66.
There is no reason to think of herbs, such as garlic, the bio-flavonoids108, silymarin, ginseng, as anti-aging, with one exception, ginger7, yet they have many medicinal uses, including preventing cancer and cardio-vascular diseases96.
We are entitled to wonder why the medical establish is so slow to advocate the widespread use of micronutrients as a prophylactic measure. The usual reasons cited include lack of corporate interest in promoting unpatentable, ergo unprofitable, vitamins and minerals, lack of nutritional training for medics plus the medical skew towards treatment rather than prevention.
In addition there are some scientific fallacies or myths that delay the wider acceptance of supplemental micronutrients. Vitamins, herbs and minerals are natural which, as far as most medics are concerned96c, makes them inferior to drugs. At the same time, because they are natural, most evolutionary biologists believe that the amounts in our diet must already be close to or at the optimum, in which case supplements are wasted. Some of the measures used by gerontologists to measure the effectiveness of anti-aging regimes are biased against micronutrients. Let’s look in more detail at these ideas:
The switch from a hunter-gather diet (nuts, berries, wild game, roots) to one based on agriculture, about 7000 years ago in the Middle East, was accompanied by a drop in average height of up to 6 inches (only regained in the West during the 20th Century); a compelling sign that the reduced food diversity that accompanies agriculture abundance resulted in widespread chronic malnourishment28a. What about modern diets, are they optimally healthy? Supplying more than the RDA of many micronutrients to already healthy people further improves their health, as demonstrated by many placebo-controlled trials47-61 and epidemiological studies11-14, a view finally endorsed in a JAMA review82. This demonstrates that our modern diet, although superior to any since hunter-gatherer days, still borders on malnourishment.
What about the pre-agricultural-farming Palaeolithic hunter-gatherer diet, perhaps that diet (nuts, berries, wild game, roots) is optimal? That we have deviated from this ‘natural’ diet is beyond dispute. If only, the myth says, we would eat like cavemen, we would be much healthier. The belief that the ‘natural’ diet is optimal seems to arise from a misunderstanding of evolution. The argument runs thus: we have evolved to optimise the metabolising of dietary micronutrients; therefore the amounts of various micronutrients in our natural diet must be optimal. This is a simply faulty logic – the conclusion (amounts of various micronutrients in our diet must be optimal) doesn’t follow from the premise (we have evolved to optimise the metabolising of dietary micronutrients).
The same illogic applies to macronutrients, where it is easier to demonstrate this fallacy. Water is a macronutrient, which our thirst mechanism fails to regulate optimally, leaving us marginally, chronically dehydrated76. For our savannah ancestors paying a visit to the watering hole was an expensive, time-consuming and risky activity due to increased exposure to waterhole predation, water-borne parasites and diseases; under these circumstances partial dehydration is a worthwhile trade-off. Our thirst mechanism is not adjusted, in the evolutionary sense, to the availability of clean, cheap water in the modern world; drinking more water than we naturally feel inclined to may be beneficial to our health75.
The same is true for feeding. Feeding, for most of our evolutionary history, has been an expensive, risky activity, involving a number of trade-offs, forcing a compromise with marginal malnutrition. Herbivores face increased predation whilst grazing and carnivores risk injury whilst hunting, for example. This makes feeding a risky activity. Feeding halts when the marginal benefit of the extra calories is outweighed by the associated foraging risks; marginal malnourishment, due to inadequate amounts of some or all micronutrients in the diet, will not necessarily generate a feeling of hunger.
Drug dosage in the literature is often expressed in units per kilogram, which yields an inappropriate inter-species scaling up by body weight; smaller mammals (e.g. rodents) generally have a higher metabolic rate per unit weight, processing food and drugs at a faster rate than larger mammals (such as humans). Scaling up dosage by body weight from a smaller to larger animal can lead to toxic dosages. For instance, scaling the rodent B6 (pyridoxine) dose up by body weight we get a human dosage of approximately 10grams/day, which would be well into the toxic range32, as low as 2g/day40. The number of calories consumed, not body weight, scales the dosage extrapolation (Appendix B) from rodent to human. Scaling up the B6 (pyridoxine) dosage by calories, rather than body weight, yields the safer 720mg/d extrapolation.
Scaling by weight has lead to two errors. First, extrapolating dosage from rodents to humans by body weight overestimates the human requirement, leading, sometimes, to toxic recommendations32, 40, undermining confidence in the validity of animal models. Second, extrapolating from known human requirements back onto rodents has lead to underestimating the requirements for rodents and yielded an influential negative lifespan study42. The amounts of various the B-vitamins, used in this negative study42, when adjusted for calorific intake, were barely at the modern RDA level. The correct procedure for extrapolating nutrient requirements is to scale body weight ratios to the power of ¾.81a-c
The incorrect scaling has also led to an overestimate of requirements for vitamin B5 (pantothenate) amongst the health industry, with recommendations into the multi-gram/day range when just over a 120 mg/d is probably sufficient. For vitamin B5 (pantothenate) this overdosing is not important since it completely non-toxic. But for vitamin B6 (pyridoxine) the overestimate induced by incorrect scaling is more serious, since the anti-aging dose (720 mg/d) is close to the toxic dose (2 g/d) 40.
Recommended Daily Allowances (RDAs)
The recommended daily allowance, or RDA, of a particular micronutrient is often set at the amount of a micronutrient required to either prevent the appearance of the appropriate deficiency syndrome (e.g. rickets (vitamin D), scurvy (vitamin C), beri-beri (B1 (thiamine)) or maximise the activity of a selected enzyme. There is no reason to suppose that (sub-clinical) normal aging is not also a micronutrient deficiency syndrome. Gauging the optimal intake from enzyme activity is also fraught with error since different enzymes will reach optimality at different cofactor concentrations, making any individual enzyme a poor biomarker. The amounts required to achieve significant life-extension are often between 30 to 400 times these RDA levels.
Many of the B-vitamins are absorbed via specific active transport mechanisms, which selectively bind to and absorb vitamin, to achieve rapid and near complete absorption. Each active transport mechanism becomes saturated above a certain level of intake. Consequently the myth has arisen that no more than this amount can be absorbed. But all the B-vitamins can also be absorbed passively by diffusion. At low concentrations such passive transport makes only an insignificant contribution to total uptake, because it is less efficient than the active transport mechanisms. At high concentrations, however, passive transport can deliver much more than rate-limited active transport. To take just one example, vitamin B12 (cobalamin), is actively absorbed via the ‘intrinsic factor’ and led to the belief that people with intrinsic factor deficit needed B12 injections. Now it is realised that oral megadoses of B12 also are effective50b, 101b, 127. The same is true for other B-vitamins, e.g. B2102.
Aging is a multifactorial process. Drugs are designed to be target-specific, although they usually have multiple unwelcome side effects. A single drug treats a single disease. So it is unreasonable to expect that a single "magic bullet" drug is going to stop or reverse a complex process such as aging. Micronutrients, such as the precursors to enzymic cofactors, on the other hand, affect the metabolism in a very primitive, basic fashion via the action of innumerable enzymes at the sub-cellular level; the effect of dietary enzymic cofactor precursors is not specific to a single tissue or organ, but is usually system-wide. It is entirely possible for something as broad as aging to be affected by micronutrients, via their effect on the enzymic cofactors, in a way that target-specific synthetic drugs simply can’t do.
Even amongst professional medics33a myths about the toxic effects of vitamins circulate and hamper their wider acceptance. The story about vitamin C and B6 (pyridoxine) causing kidney stones, for instance, is still regularly trotted out by medics and given considerable media exposure, despite it never having any empirical basis33a and actually disproved in 199689. Magnesium, with B6 (pyridoxine), also protects against kidney stones86c.
Many researchers, for example Walford33, use species maximum lifespan as the only test of whether an intervention is truly anti-aging or not. If cohort maximum lifespan exceeds the current species maximum lifespan they accept it as an anti-aging intervention, otherwise not. There are three fundamental problems with using species maximum lifespan as such a gerontological yardstick.
First, the raising of the species maximum lifespan by discovery of a longer-lived strain34 within the species or creation of a longer-lived strain by selective breeding35 invalidates the species maximum as a meaningful yardstick with any stability.
Second, use of the species maximum lifespan assumes that aging is a constant across a species. This seems rather arbitrary. Why not the select the phylum, order, class, genus, strain or even - as seems most likely - the individual65 as the level of zoological classification at which the rate of aging is presumed constant?
Third, species maximum lifespan is a statistically unfair comparison. A species maximum lifespan is typically defined against a reference population of millions of animals, whereas the number in the experimental cohort only defines the cohort lifespan. In any very large population, such as the entire species, the laws of probability decree that some very long-lived individuals will always occur (such as Jeanne Louise Calment, who lived to 122), whereas in a smaller population this is very unlikely (any of your relatives live to 122?). For this reason, whilst an experimental cohort which exceeds the species maximum is statistically very significant (e.g. for chromium picolinate), failure of a cohort to exceed the species maximum is statistically meaningless.
Inadvertent or Crypto-Calorie Restriction
Calorie restriction has extended the lifespan of a number of species, including mammals33. An animal on a calorie-restricted diet receives the full compliment of essential micronutrients (vitamins and minerals) but the calorific intake is restricted. Calorie-restricted animals only show extended lifespan when their restricted diets are enriched with increased concentrations of vitamins and minerals. Indeed it is this extra dietary micronutrient enrichment that distinguishes dietary restriction, which doesn’t extend lifespan, from calorie restriction, which does extend lifespan28a.
The life-extending mechanism of calorie restriction is probably related to glycation, although other effects may also be operative, such as the switch from anaerobic to aerobic metabolism120. Calorie restricted animals have lower fasting glucose and insulin levels and improved glucose tolerance. It may be relevant that diet restriction has been shown to increase the concentration of some vitamer coenzymes in body tissues29. This implies that the calorie restriction will also raise coenzyme levels, since calorie restriction is enriched diet restriction. If so this nicely dovetails with the hypothesis of Guarente, Sinclair et al about the interaction of the SIR2 gene and NAD (a coenzyme) to produce the calorie-restriction life-extension effect27a, 27b.
Sometimes the apparent anti-aging effect of a supplement is an artifice of inadvertently induced calorie restriction on the experimental animals. According to the hypothesis of crypto-calorie restriction the experimental animals are put off their food by the supplement’s unpleasant taste, eat less food & fewer calories and so experience the age-retarding effect of calorie restriction. To eliminate this effect the weight or dietary intake of the experimental animals must be compared and controlled for. If not a hidden or crypto- calorie restriction may induce the lifespan extension that will be falsely attributed to the dietary micronutrient.
This criticism does apply to the anti-aging micronutrients discussed here, namely dietary RNA, vitamin B5 (pantothenate) & B6 (pyridoxine) and the mineral chromium (as chromium picolinate). The weight of the experimental animals given extra dietary RNA 2a and vitamin B5 (pantothenate) 3 actually exceeded, slightly, the weight of the controls, so a crypto-calorie restriction effect could not be operative here. No reduction in food intake was observed in the experimental animals given vitamin B6 (pyridoxine)6, so again crypto-calorie restriction can be excluded as the mechanism for the observed lifespan extension.
Only with chromium would crypto-calorie restriction appear, at first sight, a theoretical possibility. Diet and weight were not reported in the chromium experiment, and a drop in insulin and glucose levels and the glycation rate were observed5a, all of which are associated with calorie restriction. But the drop in insulin and glucose levels and glycation rates have also been observed in many non-lifespan experiments with chromium, where diet restriction was not a possibility; there is no need to invoke calorie-restriction to explain the lifespan effect, since glycation is already widely implicated in aging83; the anti-glycation effect of chromium is a sufficient explanation on its own to explain the associated lifespan increase.
The hypothesis about role of enzymic cofactors in aging predicts that the lifespan extensions produced by dietary cofactor precursors such as the B-vitamins and minerals should combine approximately additively in mammals, as they have in insects.
In order of decreasing probability and increasing lifespan, we can expect dietary cofactor precursors to yield a mean average lifespan increase of at least:
We can expect an associated maximum lifespan increase to approach the mean average lifespan increase, i.e. in the range 66% to 172%, on top of the current human maximum of 122 years, i.e. approximately 200 to 300 years.
Use of the health boosting micronutrients: selenium15, 16, 54, 72, the carotenoids67, 70, flavonoids108 various herbs96 and the remaining "unofficial" B-vitamins B4 (choline), B8 (inositol) & B10 (para-aminobenzoic acid) should help to square the survival curve, raising the mean lifespan closer the new maximum lifespan. Living to, and beyond, 200 years is achievable right now.
Some micronutrients can be toxic, or have unwanted side effects, in large amounts. There is a great deal of biochemical variation between people; what is an appropriate for one individual may make someone else sick. You should consult a mainstream doctor before starting to megadose and have your medical condition monitored carefully.
Some other factors to consider:
Beware of the "rebound effect"; sudden cessation of the intake of a vitamin may induce a temporary depletion in that vitamin to below pre-supplementation levels and occasionally the appearance of the associated deficiency syndrome. This can be avoided by gradually reducing your intake over a period of weeks, rather than suddenly. The rebound effect has been observed with vitamin C (ascorbic acid) when intake was dropped from 10g/d to 125mg/d44. The rebound phenomenon is actually evidence for the effectiveness of high doses of vitamins and disproves the common mythology that excess vitamins are wasted. As the study44 found "We hypothesize that the high intake of ascorbic acid has induced the formation of increased amounts of enzymes that help convert the ascorbic acid into other substances and that these substances are valuable."
A large dose of a single B-vitamin tends to deplete levels of the other B-vitamins43a-c. To avoid this ensure you’re getting enough B5 (pantothenate) & B6 (pyridoxine) via B-complex supplements (which should supply adequate amounts of most of the other B-vitamins) and then take additional B3 as niacin, which is required in much larger amounts than the other B-vitamins.
Vitamin B3 (as nicotinamide) may be toxic in the range 3-6gm/d85. Niacin, as nicotinic acid, is generally considered less toxic40, but, still, in some individuals large doses of niacin have caused abnormal liver behaviour. Also niacin can cause an uncomfortable, although, as far as we know, harmless and temporary skin flushing. Taken as inositol hexanicotinate, which is generally regarded as non-toxic, unlike some other slow-release formulations73, removes this problem.
Neurological problems been observed with vitamin B6 (pyridoxine) in doses of over 2 g/d40; some authorities place the toxic level as low as 500mg73. The toxicity observed with B6 resembles the deficiency symptoms, and may or may not be due to depletion of other un-supplemented B-vitamins or the direct action of pyridoxine in blocking the vitamer receptor sites40, 73. Extra B2 (riboflavin) and magnesium may aid the conversion of pyridoxine to the safer, active vitamer form, pyridoxal-5-phosphate73. Notice that the lower end of the toxic range for vitamin B6 (pyridoxine) overlaps with the extrapolated optimum.
More than 200mg/d of B6 (pyridoxine) has been reported to induce a transient dependency32. As with the rebound effect this is actually an indication that the high dose is metabolically active, rather than wasted, as many authorities believe. Nevertheless, going cold turkey is probably an experience to be avoided. As with the rebound effect, should you decide to stop supplementing, the advice is to taper off any high intakes slowly, rather than quickly.
B9 (folic acid) should always be taken with vitamin B12 (cobalamin), since folic acid may mask some of the signs of a B12 deficiency (e.g. anaemia) without correcting some of the other associated neurological deficits.
Oral consumption of both melatonin22 and DHEA68a, 68c has been linked, in some animal models, with increased tumour occurrence. Human growth hormone may actually accelerate aging39. Hormone supplements may make you feel great39c, but also harm68c or kill39c you.
Selenium is toxic in the milligram range, with claims for the toxic starting level between 900ug/d73 to 6000ug/d72a. The organically-bound forms (e.g. selenomethionine) are safer than the inorganically bound forms of selenium (e.g. sodium selenate).72a Concurrent magnesium supplementation is advisable since magnesium may provide some protection against selenium toxicity45.
RNA rich diets may elevate uric acid levels. For people susceptible to gout this could a problem. Check with an expert beforehand, especially if there is a family history of gout.
The list of minerals covered here is not complete. There are many more metallic ion cofactors (boron, vanadium, molybdenum, copper, manganese etc, etc), which the constraints of time and space preclude from detailed inclusion here73.
Do not megadose with the fat-soluble vitamins, especially vitamins A, D and E. Although not discussed much here, for they are not coenzyme precursors, be aware that A & D toxicity is high and a dangerous dose is easy to accumulate, since, not being water-soluble, they are not readily excreted. If taking a number of multivitamins, try to avoid those with vitamin A. Vitamin A is probably the easiest to overdose on. To avoid vitamin A toxicity take alpha-, beta- or gamma-carotene or cryptoxanthin instead, which your body will convert into vitamin A, as needed. Some of the other carotenoids, e.g. lycopene & lutein, although they have their own benefits, don’t convert to vitamin A. Large amounts of the carotenoids will colour the skin, although this is not harmful.
Although beta-carotene decreases the risk of lung cancer for non-smokers or ex-smokers, it may increase the risk for current smokers71, at least in the short term, unless they also supplement with vitamin E69. Other carotenoids have not been as thoroughly tested and may also have the same effect.
Iron – often advised for anaemia - is not generally needed and can be harmful99; a vitamin B9 (folate) or B12 (cobalamin) deficiency more often causes anaemia.
Although no dietary supplement will contain it, be aware that inorganic hexavalent chromium is highly toxic and must be confused with the organic, trivalent forms, (such as chromium picolinate) which are non-toxic.
The author does not possess any biological or medical qualifications! Do your own reading of the subject. A good starting point is the Encyclopedia of Nutritional Supplements. Michael T Murray, (1996) ISBN 0761504109. An invaluable resource; should be read by everybody prior to supplementing. Of course this advice would be pertinent even were I a Nobel laureate.
Table 2 Coenzymes
|
Coenzyme(s) |
Source |
Action facilitated |
Comments |
|
Adenosine Triphosphate (ATP) |
Synthesised de novo and from dietary RNA |
Transfer of phosphoryl or nucleotidyl groups |
Supplies the energy for a lot of reactions |
|
S-Adenosylmethione (SAMe) |
Synthesised from methionine |
Transfer of methyl (CH3) groups |
Levels may be raised by supplementing with vitamins B2, B6, B9 & B12 |
|
Ubiquinone / Coenzyme Q10 (Co-Q10). |
Synthesised |
Lipid soluble election transfer |
Levels may be raised by supplementing with vitamin C, the B-vitamins and minerals |
|
Thiamine pyrophosphate (TPP) |
From dietary thiamine (vitamin B1) |
Transfer of 2-carbon units containing a carbonyl group |
Deficiency causes beri-beri. Counters insulin-resistance |
|
Flavin mononucleotide (FMN) & flavin adenine dinucleotide (FAD) |
From dietary riboflavin (vitamin B2) |
Oxidation-reduction reactions involving both 1- and 2-electron transfers |
Often relays electrons to and from NAD+/NADH & NADP+/NADPH |
|
Nicotinamide adenine dinucleotide (NAD+/NADH) & nicotinamide adenine dinucleotide phosphate (NADP+/NADPH) |
From dietary niacin (vitamin B3), although can also be synthesised less efficiently from dietary tryptophan |
Oxidation-reduction reactions involving just 2-electron transfers. NAD is also a substrate to PARP and Sir2 |
Dietary deficiency causes pellagra NAD is important in modulating ADP-ribose polymer metabolism, cyclic ADP-ribose synthesis, and stress response proteins, such as p53, following DNA damage. Critical for DNA repair. Helps prevent diabetes |
|
Coenzyme A (CoA) and phosphopantetheine (part of the acyl carrier protein ACP) |
From dietary pantothenate (vitamin B5) |
Acetylation (acetyl CoA) and R-acyl transfers. |
Required for the oxidation of some fuel molecules and biosynthesis of some carbohydrates and lipids, and conversion of choline to acetylcholine. Provides increased resistance to physiological stress |
|
Pyridoxal-5-phosphate (PLP) |
From dietary pyridoxine (vitamin B6) |
Transfer of groups to and from most amino acids |
Required for all protein synthesis |
|
Biotin |
Absorbed from intestinal bacteria and dietary biotin (vitamin B7) |
Carboxylation and ATP-dependent carboxylation |
High doses help regulate insulin secretion and alleviate diabetes |
|
Tetrahydofolates: 6 inter-convertible foyl coenzymes |
From dietary folate (vitamin B9) |
Transfer of a range of 1-carbon groups |
Required for biosynthesis of nucleotides, particularly thymine for DNA. |
|
Tetrahydrobiopterin |
Synthesised with the aid of 5-methyltetrahydrofolate and vitamin B12 |
Cofactor for several hydroxylases, e.g. phenylalanine hydroxylase |
Required for the biosynthesis of tyrosine from phenylalanine, biosynthesis of catecholamines and indolamines, and the neurotransmitters serotonin and dopamine. |
|
Adenosylcobalamin |
From dietary cobalamin (vitamin B12) |
Interchange of a hydrogen atom and an adjacent side chain on a carbon backbone |
|
|
Methylcobalamin |
From dietary cobalamin (vitamin B12) |
Methylation |
Required for regeneration of methionine from homocysteine |
|
Vitamin K |
Vitamin K |
Carboxylation of some glutamate residues |
Fat-soluble |
|
Uridine diphosphate (UDP) glucose |
Uracil from dietary RNA |
Glucose donor. Glucosylation |
Required for biosynthesis of glycogen |
|
Uridine diphosphate (UDP) glucuoronic acid |
Uracil from dietary RNA |
Glycosylation |
Required for biosynthesis of glycosaminoglycans and tetrahydro-curcumin-glucuronoside74from curcumin |
|
Cytidine diphosphate-choline/ ethanolamine/ diacylglycerol |
Cytosine from dietary RNA |
Lipid biosynthesis |
|
|
Carnitine |
From diet and synthesised |
Co-substrate for carnitine acyltransferase I & II, required for the transport of fatty acyl groups into the mitochondria |
Critical for mitochondrial energy release. Requires CoA as a cofactor. |
|
Lipoamide (lipoate) |
From lipoic acid in diet and synthesised |
Oxidation of a hydroxyalkyl group from TPP and transfer as an acyl group |
The dosage extrapolations are from the amounts that have had either extended lifespan or, in the absence of definitive lifespan data, had the maximum physiological effects on animals (where possible, humans). To allow for metabolic differences between larger and smaller mammals I scaled micronutrient dosage by calories; the equivalent to maintaining the same micronutrient density, i.e. amount per weight of feed. For calculational purposes I assumed a human intake of 2500 calories/day, with a dry feed weight of 1kg/day. Where direct information on calorific intake was not available I have scaled by total metabolic turnover, using the established ¾ power scaling law81, which should be approximately equivalent to calorific scaling.
Table 3 - Dosage & Toxicity
|
Micronutrient |
Extrapolated Optimal Daily Dose |
RDA for adult male/female |
Toxic Daily Dose |
|
B1 (thiamine) |
3 – 8 gm 106 |
1.5/1.1 mg |
|
|
B2 (riboflavin) |
10 mg 102 |
1.7/1.3 mg |
|
|
B3 (niacin) |
5 g 27f, 27c |
19/15 mg |
3 – 6 g85 |
|
B5 (pantothenate) |
120 mg 3 |
4/7 mg |
|
|
B6 (pyridoxine) |
720 mg 6 |
2.0/1.6 mg |
500mg73 – 2g40 |
|
B7 (biotin) |
393 - 9 mg 55d |
300 ug |
|
|
B9 (folate) |
926 ug 49 |
200/180 ug |
|
|
B12 (adenosylcobalamin) |
50 50b – 500 ug50a |
2 ug |
|
|
B12 (methylcobalamin) |
2 101a - 10 mg 101b |
2 ug |
|
|
Chromium(III) |
1 mg (of Cr) 5a-e |
- |
|
|
Magnesium |
1-2 g |
350/280 mg |
|
|
Selenium |
400 ug 16 |
70/55 ug |
900ug73 - 6000ug72a |
|
Zinc |
25 90-30 mg91 |
15 mg |
150 mg73 |
|
Alpha-lipoic acid |
600 mg 98 - 5 g |
- |
|
|
Carnitine |
1.5 – 4 gm 73 |
||
|
RNA |
250 mg 2a |
- |
|
|
Beta-carotene |
- |
60mg (smokers only) 71 |
|
|
Lycopene |
30 mg 66 |
||
|
Curcumin |
2 gm 7 |
- |
|
|
Vitamin C |
2.5 gm 77 |
60 mg |
|
|
Vitamin E (alpha-tocopherol) |
400 IU 73 |
10 mg / 15 IU |
g = gram, mg = milligram, ug = microgram
Apoenzyme – The inactive form of an enzyme, formed from amino acids and/or nucleotides. Requires the presence of specific enzymic cofactors to function.
B-vitamins – a range of water-soluble vitamins, some of which are converted in our bodies into coenzymes. The B-vitamins are thiamine (B1), riboflavin (B2), niacin (B3), choline (B4), pantothenate (B5), pyridoxine (B6), biotin (B7), inositol (B8), folate (B9), para-aminobenzoic acid (B10) and cobalamin (B12). Some classifications do not include B4, B8 and B10 (none of which are coenzymes) as B-vitamins and some classifications have the labels B3 and B5 interchanged. Only the B-numbers B1, B2, B6 & B12 have universally agreed usage.
Coenzyme – a coenzyme is a complex molecule that an enzyme requires in order to function. A coenzyme either bonds permanently onto the enzyme, forming a prosthetic group, or is required as a co-substrate by the enzyme. Apoenzymes, with the exceptions of ribozymes, are proteins constructed from amino-acids. This limits the range of their flexibility or activity. The coenzymes, by contrast, are not amino-acid based, and supply the more diverse arrangements of molecules that apoenzymes require to complete their structure and function correctly as holoenzymes. In general a particular coenzyme performs one just biochemical action, but enzymes and coenzymes have a many-to-many relationship; a particular coenzyme is typically required by a number, sometimes hundreds, of different enzymes and, conversely, one enzyme may require the presence of many coenzymes to function.
Some coenzymes are synthesised by our body, others are derived from the B-vitamins in our food. See Appendix A for a full list of coenzymes.
Cofactor – an enzymic cofactor is either a metallic ion or a coenzyme, which an inactive apoenzyme requires to function or become activated as a holoenzyme. Many different enzymes require the same cofactor(s) to function.
Enzyme – an enzyme is a protein molecule (a chain of amino acids, with the exceptions of ribozymes) produced in our body, that controls the rate of a reaction. Enzymes control virtually all reactions. Each enzyme is specific to one particular reaction or step in a metabolic pathway. There are thousands of different types of reactions going on in our body, each with their own enzyme. The same enzyme may be active in different tissues and organs.
DNA – deoxyribonucleic acid, a double-stranded repository of genetic information. Contained in the cell’s nucleus and mitochondria.
Glycation – (non-enzymic glycosylation) the harmful, uncontrolled bonding of free glucose to other molecules, particularly the amine tails of proteins, creating cross-links and, in DNA, mutations. The rate of glycation is proportional to the level of free glucose; one of the major causes of aging.
Glycosylation – the enzymic-mediated transfer of glucose or analogues. These reactions are vital and not harmful. Cf Glycation
Hayflick Limit – after Leonard Hayflick, who discovered that most tissue cells, when allowed to proliferate freely in the laboratory, cease dividing after a pre-set number of divisions; a milestone on gerontology, at the time, and widely seen, nowadays, as evidence for telomeric control.
Holoenzyme – The activated functional form of an enzyme.
NAD+/NADP+/NADH/NADPH – the active coenzyme forms of vitamin B3, derived from dietary niacin.
Niacin – Can mean any of the forms of vitamin B3 , such as niacinamide, NAD+, NADP+, nicotinic acid. Its carboxylic acid analogue is nicotinic acid, which is its usual dietary supplemented form.
Niacinamide – also known as nicotinamide. Converted into the co-enzyme forms, NAD+ etc via nicotinic acid.
PARP - poly(ADP-ribose) polymerase. An enzyme involved in the generalised excision-repair pathway, critical for repairing DNA damage.
RDA – the Recommended Daily Allowance is the amount required to eliminate a clinical deficiency. Values set by the Food and Nutrition Board of the National Research Council, 1998.
RNA – ribonucleic acid, a form of nucleic acid. Two types. Messenger RNA (mRNA) conveys the information in DNA from the nucleus to ribosomes, where transfer RNA (tRNA) helps assemble the proteins from the instructions in the mRNA.
Ribozyme – A small number of important non-proteonomic enzymes are formed from nucleotides, not amino acids. Ribozymes are believed to be the most ancient of all enzymes, evolving before the more numerous proteonomic enzymes, and still play a pivotal role in metabolism.
Telomeres – repeating sequences of DNA at the end of chromosomes. As cells divide their telomeres shorten, which is why children have longer telomeres, on average, than adults. Eventually, after sufficient cell divisions, as telomeres become too short the cells reach the Hayflick limit, cease dividing (replicative senescence) or even die (apoptosis).
Vitamin – a complex dietary micronutrient molecule, which we need to live, and which must be derived from our food, since we can’t synthesise it. Some vitamins are water-soluble and some are fat-soluble, depending on which part of the body they are active in. Not all vitamins are precursors to coenzymes.
[1a] The Use of Drosophila Melanogaster as a Screening Agent for Longevity Factors. I. Pantothenic Acid as a Longevity Factor in Royal Jelly. Thomas S Gardner, Journal of Gerontology 1(3) (1948): 1-8.
[1b] The Use of Drosophila Melanogaster as a Screening Agent for Longevity Factors. II. The Effects of Biotin, Pyridoxine, Sodium Yeast Nucleate, and Pantothenic Acid on the Life Span of the Fruit Fly. Thomas S Gardner, Journal of Gerontology 1(3) (1948): 9-13
[2a] The Effect of Yeast Nucleic Acid on the Survival Time of 600-Day-Old Albino Mice. Thomas S Gardner, Journal of Gerontology 3(?) (1946): 445-452. This reproduces the work of Robertson2b on lifelong administration of nucleic acid enriched diets, at a lower dosage.
[2b] Influence of Nucleic Acids of Various Origin upon the Growth and Longevity of the white mouse. TB Robertson in the Australian J of Experimental Biology and Medical Science, 5, (1928): 46-67
16% mean life span extension. Maximum lifespan (last 10%) extended by approximately 8-16%.
[3] Effect of pantothenic acid on the longevity of mice. Richard B Pelton and Roger J Williams in Proceedings of the Society Experimental Biology & Medicine 99 632-633, 1958. Mean lifespan extension of 19.5%. No maximum lifespan data reported.
[4] How to re-energise old mitochondria without shooting yourself in the foot. Driver C, Georgiou A in Biogerontology 2002;3(1-2):103-6
Nicotinamide increased mean lifespan in drosophila by 15%. (Private communication: Maximum lifespan (last 10%) also increased.)
[5a] Composition and Biological Activity of Chromium-Pyridine Carboxylate Complexes. GW Evans and DJ Pouchnik, Journal of Inorganic Biochemistry 49, pg 177-187 (1993). Describes the action of dietary chromium picolinate (relative to chromium chloride and chromium nicotinate) in reducing glycation & plasma glucose levels in rats as they aged.
[5b] Longevity effect of chromium picolinate--'rejuvenation' of hypothalamic function? McCarty MF in Med Hypotheses 1994 Oct;43(4):253-65 "The first rodent longevity study with the insulin-sensitizing nutrient chromium picolinate has reported a dramatic increase in both median and maximal lifespan.." Gives additional information about the Evans-Meyer-Pouchnik chromium picolinate experiment on rats: Cohort maximum lifespan (last survivor) was 48 months, extending the previous species maximum by 15%.
[5c] Chromium picolinate increases longevity. Evans GW, Meyer LK in AGE (the Journal of the American Aging Association) Oct 1992; 15(4), 134.
[5d] Chromium Picolinate. Gary W Evans, (1996) ISBN 0895299119. Gives additional information about the Evans-Meyer-Pouchnik chromium picolinate experiment on rats: Mean lifespan extension of 27%
[5e] The Longevity Factor: Chromium Picolinate. RA Passwater, (1993), ISBN 0879836199.
[6] Favorable Effects of Pyridoxine HCl on the aging process. Lindseth K, Dictor M & Miquel J in AGE 5(4), 143, 1982. Late middle-age intervention gave mean total lifespan extension of 11%. No maximum lifespan data reported.
[7] Tetrahydrocurcumin Prolongs Survival Curves of Male C57BL Mice. Kitani K, Osawa T in AGE 25, 2002 Middle age intervention resulted in mean lifespan extension of 11%, maximum lifespan (last 10%) extended by 7%. Curcumin, a saffron-yellow pigment, is one of the active ingredients of the spice Turmeric (ginger family). The other curcuminoids in Turmeric may also be potent antioxidants. Curcumin, which is not an enzymic cofactor, may not synergistically combine with the other anti-aging enzymic cofactors, so we exclude it from any combination extrapolations.
[9] Biochemistry 2nd Edition. Donald & Judith G Voet (1995) ISBN 047158651X. Page 1184 shows the plot of cancer mortality against age. Cancer mortality rate rises, with time, as a quintic, approximately, from age 20 years, suggesting that the mutation rate is constant or rises slowly throughout adult life and that cancers are the result of, on average, 5 independent mutations.
[10a] Elevated intakes of supplemental chromium improve glucose and insulin variables in individuals with type 2 diabetes. Anderson RA, Cheng N, Bryden NA, Polansky MM, Cheng N, Chi J, Feng J in Diabetes 1997 Nov;46(11):1786-91
[10b] Nutritional factors influencing the glucose/insulin system: chromium. Anderson RA in J Am Coll Nutr 1997 Oct;16(5):404-10
[10c] Beneficial effects of chromium in people with type 2 diabetes, and urinary chromium response to glucose load as a possible indicator of status. Bahijri SM, Mufti AM in Biol Trace Elem Res 2002 Feb;85(2):97-109
[10d] [Chromium in the treatment of clinical diabetes mellitus] Ravina A, Slezack L in Harefuah 1993 Sep;125(5-6):142-5, 191
"We gave 243 diabetic patients Cr (200 mcg/d) to study its effect on blood glucose balance. 105 were Type 1 (IDDM) and 138 Type 2 (NIDDM). Cr reduced insulin, sulfonylurea or metformin requirements in 115 patients. The success rate was greater in those with NIDDM (57.2%) than in those with IDDM (33.6%). More women, of either type, reacted than men (62.5 vs 50% in NIDDM and 37.6 vs 28.6% in IDDM). A placebo was ineffective."
[11a] Multivitamin use, folate, and colon cancer in women in the Nurses' Health Study. Giovannucci E, Stampfer MJ, Colditz GA, Hunter DJ, Fuchs C, Rosner BA, Speizer FE, Willett WC in Ann Intern Med 1998 Oct 1;129(7):517-24
Long-term use of folate (>15 years) supplements produced a 4-fold reduction in the incidence of colon cancer.
[11b] Are dietary factors involved in DNA methylation associated with colon cancer? Slattery ML, Schaffer D, Edwards SL, Ma KN, Potter JD in Nutr Cancer 1997;28(1):52-62
"We did not observe strong independent associations between folate, vitamin B6, vitamin B12, methionine, or alcohol and risk of colon cancer after adjusting for body size, physical activity, cigarette smoking patterns, energy intake, and dietary intake of fiber and calcium. However, when assessing the associations between colon cancer and a composite dietary profile based on alcohol intake, methionine, folate, vitamin B12, and vitamin B6, we observed a trend of increasing risk as one moved from a low- to a high-risk group"
[12] Long-term nutrient intake and early age-related nuclear lens opacities. Jacques PF, Chylack LT Jr, Hankinson SE, Khu PM, Rogers G, Friend J, Tung W, Wolfe JK, Padhye N, Willett WC, Taylor A in Arch Ophthalmol 2001 Jul;119(7):1009-19
"These results provide additional evidence that antioxidant nutrients play a role in the prevention of age-related nuclear lens opacities."
[13] Vitamin E and vitamin C supplement use and risk of all-cause and coronary heart disease mortality in older persons: the Established Populations for Epidemiologic Studies of the Elderly. Losonczy KG, Harris TB, Havlik RJ in Am J Clin Nutr 1996 Aug;64(2):190-6
34% reduction in mortality over 9 years from vitamin E use
42% reduction in mortality over 9 years from vitamin C & E
[14] Vitamin C intake and mortality among a sample of the United States population. Enstrom JE, Kanim LE, Klein MA in Epidemiology 1992 May;3(3):194-202
35% reduction in mortality over 10 years from vitamin C use
[15] Effects of selenium supplementation for cancer prevention in patients with carcinoma of the skin. A randomized controlled trial. Nutritional Prevention of Cancer Study Group. Clark LC, Combs GF Jr, Turnbull BW, Slate EH, Chalker DK, Chow J, Davis LS, Glover RA, Graham GF, Gross EG, Krongrad A, Lesher JL Jr, Park HK, Sanders BB Jr, Smith CL, Taylor JR. JAMA 1996 Dec 25;276(24):1957-63
200ug/d for 4.5 years resulted in a 17% reduction of totality morality by over 11 years (in total), due to a 50% reduction of (all) cancer mortality, 37% reduction in (all) cancer occurrence
[16] The New Supernutrition. Richard Passwater (1991) ISBN 0671700715. Pages 127/8 contain the selenium - zero cancer extrapolations.
[17] "How Cancer Arises", Scientific American, Sept 1996, 32-40. An all-cancer issue. Explains how virtually all adult cancers arise as a result of approximately 4-5 independent mutations in a cell.
[18] The role of folic acid and Vitamin B12 in genomic stability of human cells. Fenech M in Mutation Research 2001 Apr 18;475(1-2):57-67
"Dietary intakes above the current RDI may be particularly important in those with extreme defects in the absorption and metabolism of these Vitamins, for which ageing is a contributing factor."
[19] Methylation. Mitchell T, Life Extension, August 1998. An excellent introduction to methylation and its possible role in aging.
[20] Anabolic effects of insulin on bone suggest a role for chromium picolinate in preservation of bone density. McCarty MF in Med Hypotheses 1995 Sep;45(3):241-6
[21] Chromium picolinate decreases calcium excretion and increases dehydroepiandrosterone (DHEA) in post-menopausal women. Evans GW, Swenson G, Walters K in FASEB Journal 9:525, 1995
[22] Melatonin increases both life span and tumor incidence in female CBA mice. Anisimov VN, Zavarzina NY, Zabezhinski MA, Popovich IG, Zimina OA,
Shtylick AV, Arutjunyan AV, Oparina TI, Prokopenko VM, Mikhalski AI, Yashin AI in J Gerontol A Biol Sci Med Sci. 2001 Jul;56(7):B311-23.
[23a] Selenium content of Brazil nuts from two geographic locations in Brazil. Chang JC, Gutenmann WH, Reid CM, Lisk DJ in Chemosphere 1995 Feb;30(4):801-2
[23b] A selenoprotein in the plant kingdom. Mass spectrometry confirms that an opal codon (UGA) encodes selenocysteine in Chlamydomonas reinhardtii gluththione peroxidase. Fu LH, Wang XF, Eyal Y, She YM, Donald LJ, Standing KG, Ben-Hayyim G in J Biol Chem 2002 Jul 19;277(29):25983-91
[24a] Nucleic Acid Therapy in Aging and Degenerative Disease. Benjamin S Frank, MD. (1968) Library of Congress Catalog Card # 68-59227
[24b] Dr Frank’s No Aging Diet. Benjamin S Frank & Philip Miele, (1976) ISBN 0803753497. Recommends 1 – 1.5 g/day of RNA
[25a] Folate deficiency causes uracil misincorporation into human DNA and chromosome breakage: Implications for cancer and neuronal damage. Blount BC, Mack MM, Wehr CM, MacGregor JT, Hiatt RA, Wang G, Wickramasinghe SN, Everson RB, Ames BN in Proc Natl Acad Sci USA 94 (1997) pp 3290-3295
[25b] DNA damage in folate deficiency. Blount BC, Ames BN in Baillieres Clin Haematol 1995 Sep;8(3):461-78
[26a] Dietary nucleotides and gut mucosal defence. Grimble GK in Gut 1994 Jan;35(1Suppl):S46-S51
[26b] The role of dietary sources of nucleotides in immune function: a review. Kulkarni AD, Rudolph FB, Van Buren CT in J Nutr 1994 Aug;124(8 Suppl):1442S-1446S
.
[27a] Requirement of NAD and SIR2 for life-span extension by calorie restriction in Saccharomyces cerevisiae. Lin SJ, Defossez PA, Guarente L in Science 2000 Sep 22;289(5487):2126-2128
[27b] Manipulation of a Nuclear NAD+ Salvage Pathway Delays Aging without Altering Steady-state NAD+ Levels. Anderson RM, Bitterman KJ, Wood JG, Medvedik O, Cohen H, Lin SS, Manchester JK, Gordon JI, Sinclair DA in J Biol Chem 2002 May 24;277(21):18881-90.
[27c] Oral Niacin Prevents Photocarcinogenesis and Photoimmunosuppression in mice. Gensler HL, Williams T, Huang AC, Jacobson EL in Nutrition and Cancer 34(1) (1999), pg 36-41. The relationship between dietary intake of niacin and tissue NAD elevation is detailed in the main body of the article. The UV-irradiated mice on a diet with 0.003%, 0.1%, 0.5% & 1.0% niacin had a 0.72, 0.60, 0.48 & 0.40 tumours/mouse, respectively.
[27d] Mapping the role of NAD metabolism in prevention and treatment of carcinogenesis. Jacobson EL, Shieh WM, Huang AC in Mol Cell Biochem 1999 Mar;193(1-2):69-74 NAD is elevated by niacin in many human tissues.
[27e] Evaluating the role of niacin in human carcinogenesis. Jacobson EL, Dame AJ, Pyrek JS, Jacobson MK. Biochimie 1995;77(5):394-8
[27f] Protective effect of nicotinamide on bracken fern induced carcinogenicity in rats. Pamukcu AM, Milli U, Bryan GT in Nutr Cancer 1981;3(2):86-93
0.5% nicotinamide in diet cut the induced cancer rate by 40%
[27g] Fifteen year mortality in Coronary Drug Project patients: long-term benefit with niacin. Canner PL, Berge KG, Wenger NK, Stamler J, Friedman L, Prineas RJ, Friedewald W in J Am Coll Cardiol 1986 Dec;8(6):1245-55
"Mortality in the niacin group was 11% lower than in the placebo group (52.0 versus 58.2%; p = 0.0004). "
[28a] Why We Age: What Science is Discovering About the body’s journey through life. Steve Austad (1997). ISBN 0471296465. A must-read book for everyone interested in aging. Page 31 for farming-induced malnourishment. Pages 82 & 184 detail the importance of diet enrichment in calorie restriction
[28b] The Selfish Gene. Richard Dawkins (1976). ISBN 0586083162. Probably the best and most influential of all modern popular books on evolutionary biology.
[28c] The evolution of ageing and longevity. Kirkwood TB, Holliday R in Proc R Soc Lond B Biol Sci 1979 Sep 21;205(1161):531-46
[29] Changes Produced by Starvation in the Vitamin Content of Rat Tissues. Flinn BC, Pilgrim FJ, Gregg HS and Axelrod AE in Soc Exper Biol & Med 63:523-528 1937
[30] Origin of the metazoan phyla: molecular clocks confirm paleontological estimates. Ayala FJ, Rzhetsky A, Ayala FJ in Proc Natl Acad Sci U S A 1998 Jan 20;95(2):606-11
[31] Molecular phylogeny of Rodentia, Lagomorpha, Primates, Artiodactyla, and Carnivora and molecular clocks. Li WH, Gouy M, Sharp PM, O'hUigin C, Yang YW in Proc Natl Acad Sci U S A 1990 Sep;87(17):6703-7
[32] A Guide to AntiAging Drugs. Thomas Donaldson (1997) ISBN 096421900 Is the most compact source of anti-aging information available and the inspiration for this monograph.
[33a] The 120 Year Diet. Roy L Walford (1986) ISBN 0-671649042-495. Mostly about calorie restriction, but also contains a useful section debunking some of the common myths about vitamins (pages 150-154) e.g. that vitamin C causes kidney stones.
[33b] Maximum Lifespan. Roy L Walford (1983) ISBN 0-393-01649-8. Concentrates on calorie restriction.
[34] Extended life-span conferred by cotransporter gene mutations in Drosophila. Rogina B, Reenan RA, Nilsen SP, Helfand SL in Science 2000 Dec 15;290(5499):2137-40 The "INDY" gene.
[35] Selection on stress resistance increases longevity in Drosophila melanogaster. Rose MR, Vu LN, Park SU, Graves JL Jr in Exp Gerontol 1992;27(2):241-50
[37a] Age-associated mitochondrial oxidative decay: improvement of carnitine acetyltransferase substrate-binding affinity and activity in brain by feeding old rats acetyl-L- carnitine and/or R-alpha -lipoic acid. Liu J, Killilea DW, Ames BN in Proc Natl Acad Sci U S A 2002 Feb 19;99(4):1876-81
[37b] Memory loss in old rats is associated with brain mitochondrial decay and RNA/DNA oxidation: partial reversal by feeding acetyl-L-carnitine and/or R-alpha -lipoic acid. Liu J, Head E, Gharib AM, Yuan W, Ingersoll RT, Hagen TM, Cotman CW, Ames BN in Proc Natl Acad Sci U S A. 2002 Feb 19;99(4):2356-61.
[37c] Feeding acetyl-L-carnitine and lipoic acid to old rats significantly improves metabolic function while decreasing oxidative stress. Hagen TM, Liu J, Lykkesfeldt J, Wehr CM, Ingersoll RT, Vinarsky V, Bartholomew JC, Ames BN in Proc Natl Acad Sci U S A. 2002 Feb 19;99(4):1870-5.
[37d] Acylcarnitine profile in tissues and body fluids of biotin-deficient rats with and without L-carnitine supplementation. Shigematsu Y, Bykov IL, Liu YY, Nakai A, Kikawa Y, Sudo M, Fujioka M in J Inherit Metab Dis 1994;17(6):678-90
[38a] Chemical qualities of water that contribute to human health in a positive way. Hopps HC, Feder GL in Sci Total Environ. 1986 Oct;54:207-16.
[38b] Magnesium status and ageing: an update. Durlach J, Bac P, Durlach V, Rayssiguier Y, Bara M, Guiet-Bara A in Magnes Res 1998 Mar;11(1):25-42
[38c] Magnesium and ageing. II. Clinical data: aetiological mechanisms and pathophysiological consequences of magnesium deficit in the elderly. Durlach J, Durlach V, Bac P, Rayssiguier Y, Bara M, Guiet-Bara A in Magnes Res 1993 Dec;6(4):379-94
[38d] Role of magnesium in genomic stability. Hartwig A. in Mutat Res 2001 Apr 18;475(1-2):113-21
[39a] Effects of long-term elevated serum levels of growth hormone on life expectancy of mice: lessons from transgenic animal models. Wolf E, Kahnt E, Ehrlein J, Hermanns W, Brem G, Wanke R in Mech Ageing Dev 1993 May;68(1-3):71-87
[39b] Assessment of growth parameters and life span of GHR/BP gene-disrupted mice. Coschigano KT, Clemmons D, Bellush LL, Kopchick JJ in Endocrinology 2000 Jul;141(7):2608-13
[39c] Effects of growth hormone and insulin-like growth factor 1 deficiency on ageing and longevity. Laron Z in Novartis Found Symp 2002;242:125-37; discussion 137-42
"In conclusion longstanding GH/IGF1 deficiency affects several parameters of the ageing process without impairing lifespan, and as shown in animal models prolongs longevity. In contrast high GH/IGF1 levels accelerate death."
[40] The Vitamins: Fundamental Aspects in Nutrition and Health 2nd Edition. Gerald F Combs, Jr (1998) ISBN 0121834921
[41a] Serum folate and the severity of atrophy of the neocortex in Alzheimer disease: findings from the Nun study. DA Snowdon, CL Tully, CD Smith, KP Riley, WR Markesbery in Am J Clin Nutr 2000 Apr;71(4):993-8
"Previous studies suggested that low concentrations of folate in the blood are related to poor cognitive function, dementia, and Alzheimer disease-related neurodegeneration of the brain […]The correlation between serum folate and the severity of atrophy of the neocortex was -0.40 (P = 0.03). Among a subset of 15 participants with significant numbers of Alzheimer disease lesions in the neocortex, the correlation between folate and atrophy was -0.80 (P = 0.0006). Atrophy may be specific to low folate because none of the 18 other nutrients, lipoproteins, or nutritional markers measured in the blood had significant negative correlations with atrophy. CONCLUSIONS: Among elderly Catholic sisters who lived in one convent, ate from the same kitchen, and were highly comparable for a wide range of environmental and lifestyle factors, low serum folate was strongly associated with atrophy of the cerebral cortex."
[41b] B vitamins, homocysteine, and neurocognitive function in the elderly. Selhub J, Bagley LC, Miller J, Rosenberg IH in Am J Clin Nutr 2000 Feb;71(2):614S-620S.
"recent studies have shown associations between loss of cognitive function or Alzheimer disease and inadequate B vitamin status."
[41c] Vitamin B(12) and folate in relation to the development of Alzheimer's disease. Wang HX, Wahlin A, Basun H, Fastbom J, Winblad B, Fratiglioni L in Neurology 2001 May 8;56(9):1188-94
"This study suggests that vitamin B(12) and folate may be involved in the development of AD. A clear association was detected only when both vitamins were taken into account, especially among the cognitively intact subjects."
[41d] Alzheimer disease: protective factors. Nourhashemi F, Gillette-Guyonnet S, Andrieu S, Ghisolfi A, Ousset PJ, Grandjean H, Grand A, Pous J, Vellas B, Albarede JL in Am J Clin Nutr 2000 Feb;71(2):643S-649S
"Several studies have shown the existence of a correlation between cognitive skills and the serum concentrations of folate, vitamin B-12, vitamin B-6"
[41e] Folates and prevention of disease. Molloy AM, Scott JM in Public Health Nutr 2001 Apr;4(2B):601-9
"In particular, long-term folic acid supplementation may reduce risk of colorectal cancer substantially. Various mental disorders including Alzheimer's Disease have been associated with low folate status or elevated plasma homocysteine."
[41f] Alzheimer's disease: insights from epidemiology. McDowell I in Aging (Milano) 2001 Jun;13(3):143-62
"Physical activity appears beneficial, as does a diet with high levels of vitamins B6, B12 and folate."
[41g] New perspectives on folate status: a differential role for the vitamin in cardiovascular disease, birth defects and other conditions. Lucock M, Daskalakis I in Br J Biomed Sci 2000;57(3):254-60
"In recent years, there has been heightened interest in the B vitamin folic acid, initially through its role in reducing neural tube defects, such as spina bifida, and, more recently, through its relationship with homocysteine and consequently the beneficial role it would seem to play in occlusive vascular disease. In addition, its sphere of influence may extend beyond these important conditions to include several cancers, Alzheimer's disease and affective disorders."
[41h] Low serum vitamin B12 in Alzheimer-type dementia. Cole MG, Prchal JF in Age Ageing 1984 Mar;13(2):101-5
"Serum vitamin B12 levels were significantly lower and serum vitamin B12 deficiency was significantly more frequent in subjects with Alzheimer-type dementia and were independent of age, sex, haematological abnormality or serum folate."
[42] The Effect of Coffee, Human Diets, and Inheritance upon the Life Span of Rats. Sperling GA, Loosli JK, LL Barnes, McCay CM in J Gerontology 1, 426-432 (1946)
[43a] Does a single vitamin B-supplementation induce functional vitamin B-deficiency? Naurath HJ, Riezler R, Putter S, Ubbink JB in Clin Chem Lab Med 2001 Aug;39(8):768-71
"this confirms the hypothesis that a combined supplementation with the vitamins B6 and folate (and B12) is superior to folate alone in order to lower homocysteine"
[43b] Plasma folate but not vitamin B(12) or homocysteine concentrations are reduced after short-term vitamin B(6) supplementation. Bosy-Westphal A, Holzapfel A, Czech N, Muller MJ in Ann Nutr Metab 2001;45(6):255-8
[43c] Niacin (nicotinic acid) in non-physiological doses causes hyperhomocysteineaemia in Sprague-Dawley rats. Basu TK, Makhani N, Sedgwick G in Br J Nutr 2002 Feb;87(2):115-9
"Male Sprague-Dawley rats were given a nutritionally adequate, semi-synthetic diet containing niacin at a level of either 400 or 1000mg/kg diet (compared to 30mg/kg in the control diet) for up to 3 months. Supplementation with niacin (1,000 mg/kg diet) […] was accompanied by a significant decrease in plasma concentrations of vitamins B6 and B12, which are cofactors for the metabolism of homocysteine."
[43d] Low-dose vitamin B-6 effectively lowers fasting plasma homocysteine in healthy elderly persons who are folate and riboflavin replete. McKinley MC, McNulty H, McPartlin J, Strain JJ, Pentieva K, Ward M, Weir DG, Scott JM in Am J Clin Nutr 2001 Apr;73(4):759-64
[44] Evidence of rebound effect with ascorbic acid. Tsao CS, Salimi SL in Med Hypotheses 1984 Mar;13(3):303-10
[45] Effect of dietary selenium and magnesium on human mammary tumor growth in athymic nude mice. Yan L, Boylan LM, Spallholz JE in Nutr Cancer 1991;16(3-4):239-48
[46] Cytoplasmic genomes that confer additional longevity in Drosophila melanogaster. Driver C, Tawadros N in Biogerontology 2000;1(3):255-60
[47] Optimization of dietary folate or low-dose folic acid supplements lower homocysteine but do not enhance endothelial function in healthy adults, irrespective of the methylenetetrahydrofolate reductase (C677T) genotype. Pullin CH, Ashfield-Watt PA, Burr ML, Clark ZE, Lewis MJ, Moat SJ, Newcombe RG, Powers HJ, Whiting JM, McDowell IF in J Am Coll Cardiol 2001 Dec;38(7):1799-805
[48] Effects of vitamin B12, folate, and vitamin B6 supplements in elderly people with normal serum vitamin concentrations. Naurath HJ, Joosten E, Riezler R, Stabler SP, Allen RH, Lindenbaum J in Lancet 1995 Jul 8;346(8967):85-9
"The response rate to vitamin supplements supports the notion that metabolic evidence of vitamin deficiency is common in the elderly, even in the presence of normal serum vitamin levels. "
[49] The effect of folic acid supplementation on plasma homocysteine in an elderly population. Rydlewicz A, Simpson JA, Taylor RJ, Bond CM, Golden MH in QJM 2002 Jan;95(1):27-35
"a total daily folic acid intake of 926 microg per day would be required to ensure that 95% of the elderly population would be without cardiovascular risk from folate deficiency. DISCUSSION: A daily folic acid intake of 926 microg is unlikely to be achieved by diet alone. Individual supplementation or fortification of food with folic acid will be required to reach this target."
[50a] Vitamin supplements and cardiovascular risk: review of the randomized trials of homocysteine-lowering vitamin supplements. Clarke R, Armitage J in Semin Thromb Hemost 2000;26(3):341-8
"Hence, in typical populations, daily supplementation with both 0.5 to 5 mg folic acid and about 0.5 mg vitamin B12 would be expected to reduce homocysteine levels by one quarter to one third (from about 12 micromol/L to about 8 to 9 micromol/L)."
[50b] A randomized, double-blind, placebo-controlled study of oral vitamin B12 supplementation in older patients with subnormal or borderline serum vitamin B12 concentrations. Seal EC, Metz J, Flicker L, Melny J in J Am Geriatr Soc 2002 Jan;50(1):146-51
"Cyanocobalamin supplementation of 50 microg but not 10 microg daily produced a significant increase in serum vitamin B12. This result has implications for the management of patients with subnormal or borderline serum vitamin B12 concentrations and for food fortification with vitamin B12."
[51] Multivitamin/mineral supplementation improves plasma B-vitamin status and homocysteine concentration in healthy older adults consuming a folate-fortified diet. McKay DL, Perrone G, Rasmussen H, Dallal G, Blumberg JB in J Nutr 2000 Dec;130(12):3090-6
"Plasma folate, pyridoxal phosphate (PLP) and vitamin B-12 concentrations were increased 41.6, 36.5 and 13.8%, respectively, in the supplemented group, whereas no changes were observed in the placebo group. The mean homocysteine concentration decreased 9.6% in the supplemented group (P: < 0.001) and was unaffected in the placebo group."
[52a] Effects of folic acid and combinations of folic acid and vitamin B-12 on plasma homocysteine concentrations in healthy, young women. Bronstrup A, Hages M, Prinz-Langenohl R, Pietrzik K in Am J Clin Nutr 1998 Nov;68(5):1104-10
"These results suggest that the addition of vitamin B-12 to folic acid supplements or enriched foods maximizes the reduction of homocysteine and may thus increase the benefits of the proposed measures in the prevention of vascular disease and neural tube defects."
[52b] Importance of both folic acid and vitamin B12 in reduction of risk of vascular disease. Quinlivan EP, McPartlin J, McNulty H, Ward M, Strain JJ, Weir DG, Scott JM in Lancet 2002 Jan 19;359(9302):227-8
"a fortification policy based on folic acid and vitamin B12, rather than folic acid alone, is likely to be much more effective at lowering of homocysteine concentrations, with potential benefits for reduction of risk of vascular disease."
[52c] Folate and vitamin B6 from diet and supplements in relation to risk of coronary heart disease among women. Rimm EB, Willett WC, Hu FB, Sampson L, Colditz GA, Manson JE, Hennekens C, Stampfer MJ in JAMA 1998 Feb 4;279(5):359-64
"the relative risks (RRs) of CHD between extreme quintiles were 0.69 (95% confidence interval [CI], 0.55-0.87) for folate (median intake, 696 microg/d vs 158 microg/d) and 0.67 (95% CI, 0.53-0.85) for vitamin B6 (median intake, 4.6 mg/d vs 1.1 mg/d). Controlling for the same variables, the RR was 0.55 (95% CI, 0.41-0.74) among women in the highest quintile of both folate and vitamin B6 intake compared with the opposite extreme."
[53] Folate, vitamin B12, homocysteine status and DNA damage in young Australian adults. Fenech M, Aitken C, Rinaldi J in Carcinogenesis 1998 Jul;19(7):1163-71
"The results from this study suggest that (i) MNC [micronucleated cells] frequency is minimized when plasma HC [homocysteine] is below 7.5 micromol/l and serum vitamin B12 is above 300 pmol/l and (ii) dietary supplement intake of 700 microg folic acid and 7 microg vitamin B12 is sufficient to minimize MNC frequency and plasma HC. Thus, it appears that elevated plasma HC, a risk factor for cardiovascular disease, may also be a risk factor for chromosome damage."
[54a] Supplementation with selenium and human immune cell functions. II. Effect on cytotoxic lymphocytes and natural killer cells. Kiremidjian-Schumacher L, Roy M, Wishe HI, Cohen MW, Stotzky G in Biol Trace Elem Res 1994 Oct-Nov;46(1-2):183
"The results indicated that the immunoenhancing effects of selenium in humans require supplementation above the replete levels produced by normal dietary intake."
[54b] Anticarcinogenic effects of selenium. Schrauzer GN in Cell Mol Life Sci 2000 Dec;57(13-14):1864-73
"Selenium (Se) exerts its anticarcinogenic effects by multiple mechanisms. […] For maximal utilization of its cancer-protective potential, Se supplementation should start early in life and be maintained over the entire lifespan."
[54c] Chemopreventive agents: selenium. Combs GF Jr, Gray WP in Pharmacol Ther 1998 Sep;79(3):179-92
"The antitumorigenic activities have been associated with Se intakes that correct nutritionally deficient status in animals, as well as higher intakes that are substantially greater than those associated with maximal expression of the selenocysteine-containing enzymes. Therefore, it is proposed that while some cancer protection, particularly that involving antioxidant protection, involves selenoenzymes, specific Se metabolites, which are produced in significant amounts at relatively high Se intakes, also discharge antitumorigenic functions. According to this two-stage model of the roles of Se in cancer prevention, individuals with nutritionally adequate Se intakes may benefit from Se supplementation."
[55a] Evidence for synergism between chromium and nicotinic acid in the control of glucose tolerance in elderly humans. Urberg M, Zemel MB in Metabolism 1987 Sep;36(9):896-9
"Sixteen healthy elderly volunteers were divided into three groups and given either 200 micrograms Cr, 100 mg nicotinic acid, or 200 micrograms Cr + 100 mg nicotinic acid daily for 28 days and evaluated on days 0 and 28. Fasting glucose and glucose tolerance were unaffected by either chromium or nicotinic acid alone. In contrast, the combined chromium-nicotinic acid supplement caused a 15% decrease in a glucose area integrated total (p less than .025) and a 7% decrease in fasting glucose."
[55b] Effect of chromium supplementation on glucose tolerance and lipid profile. Bahijri SM in Saudi Med J 2000 Jan;21(1):45-50
"Improved glucose control, and lipid profile following chromium supplement suggests the presence of low chromium status in the studied population. However, serum chromium could not be recommended for use as an indicator of chromium status as subjects with widely varying levels responded favorably to the chromium supplement."
[55c] The safety and efficacy of high-dose chromium. Lamson DS, Plaza SM in Altern Med Rev 2002 Jun;7(3):218-35
"The beneficial effects of chromium on serum glucose and lipids and insulin resistance occur even in the healthy."
[55d] High-dose biotin, an inducer of glucokinase expression, may synergize with chromium picolinate to enable a definitive nutritional therapy for type II diabetes. McCarty MF in Med Hypotheses 1999 May;52(5):401-6
[55e] Beneficial effect of chromium-rich yeast on glucose tolerance and blood lipids in elderly subjects. Offenbacher EG, Pi-Sunyer FX in Diabetes 1980 Nov;29(11):919-25
"Thus, chromium-rich brewers' yeast improved glucose tolerance and total lipids in elderly subjects, while chromium-poor torula yeast did not. An improvement in insulin sensitivity also occurred with brewers' yeast supplementation. This supports the thesis that elderly people may have a low level of chromium and that an effective source for chromium repletion, such as brewers' yeast, may improve their carbohydrate tolerance and total lipids."
[55f] Effects of chromium supplementation on fasting insulin levels and lipid parameters in healthy, non-obese young subjects. Wilson BE, Gondy A in Diabetes Res Clin Pract 1995 Jun;28(3):179-84
"However, those individuals [6/15] within the chromium group with initial fasting IRI levels greater than 35 pmol/l had a significant decrease in IRI level after supplementation (P < 0.03) despite no significant changes in serum lipids. These subjects may benefit from chromium supplementation by improving insulin sensitivity and cardiovascular risk over time."
[56] Effect of vitamin and trace-element supplementation on cognitive function in elderly subjects. Chandra RK in Nutrition 2001 Sep;17(9):709-12
"Cognitive functions improved after oral supplementation with modest amounts of vitamins and trace elements. This has considerable clinical and public health significance. We recommend that such a supplement be provided to all elderly subjects because it should significantly improve cognition and thus quality of life and the ability to perform activities of daily living. Such a nutritional approach may delay the onset of Alzheimer's disease."
[57a] Vitamin supplementation for 1 year improves mood. Benton D, Haller J, Fordy J in Neuropsychobiology 1995;32(2):98-105
"One hundred and twenty-nine young healthy adults took either 10 times the recommended daily dose of 9 vitamins, or a placebo, under a double-blind procedure, for a year."... "this improvement in mood was associated in particular with improved riboflavin and pyridoxine status. In females baseline thiamin status was associated with poor mood and an improvement in thiamin status after 3 months was associated with improved mood"
[57b] Improvement of fine motoric movement control by elevated dosages of vitamin B1, B6, and B12 in target shooting. Bonke D, Nickel B in Int J Vitam Nutr Res Suppl 1989;30:198-204
"In both studies, marksmen in the vitamin-treated groups showed statistically significant, considerably improved firing accuracy as measured by the number of points achieved within a series of 20 shots at each examination. In study 2 the degree of improvement was linearly dependent on the duration of vitamin treatment"
[58] The effects of an oral multivitamin combination with calcium, magnesium, and zinc on psychological well-being in healthy young male volunteers: a double-blind placebo-controlled trial. Carroll D, Ring C, Suter M, Willemsen G in Psychopharmacology (Berl) 2000 Jun;150(2):220-5
"These findings demonstrate that Berocca [a multivitamin and mineral supplement] significantly reduces anxiety and perceived stress."
[59] Effect of vitamin and trace element supplementation on immune indices in healthy elderly. Pike J, Chandra RK in Int J Vitam Nutr Res 1995;65(2):117-21
"Supplementation with micronutrients can play a crucial role in the maintenance of normal immune function in the elderly."
[60] Nucleotides as immunomodulators in clinical nutrition. Grimble GK, Westwood OM in Curr Opin Clin Nutr Metab Care 2001 Jan;4(1):57-64
"supplementation of infant formula milk leads to improved growth and reduced susceptibility to infection. Animal studies have confirmed some of these data." … "Nucleotide supplementation has also been shown to improve some aspects of tissue recovery from ischaemia/reperfusion injury or radical resection." … "We propose that dietary nucleotides should be considered within a pharmacological and metabolic framework."
[61] Dietary nucleotides prevent decrease in cellular immunity in ground-based microgravity analog. Yamauchi K, Hales NW, Robinson SM, Niehoff ML, Ramesh V, Pellis NR, Kulkarni AD in J Appl Physiol 2002 Jul;93(1):161-6
"These results suggest that exogenous nucleotide supplementation, especially uracil, of normal diet is beneficial in the maintenance and restoration of the immune response".
[62a] Wild-derived inbred mouse strains have short telomeres. Hemann MT, Greider CW in Nucleic Acids Res 2000 Nov 15;28(22):4474-8.
"We found no correlation of telomere length with lifespan, even among closely related inbred mouse strains. Thus, while telomere length plays a role in cellular lifespan in cultured human cells, it is not a major factor in determining organismal lifespan."
[62b] Human is a unique species among primates in terms of telomere length. Kakuo S, Asaoka K, Ide T in Biochem Biophys Res Commun 1999 Sep 24;263(2):308-14
[62c] The reserve-capacity hypothesis: evolutionary origins and modern implications of the trade-off between tumor-suppression and tissue-repair. Weinstein BS, Ciszek D Exp Gerontol 2002 May;37(5):615-27
[62d] Telomerase and differentiation in multicellular organisms: turn it off, turn it on, and turn it off again. Forsyth NR, Wright WE, Shay JW in Differentiation 2002 Jan;69(4-5):188-97
[63a] The shortest telomere, not average telomere length, is critical for cell viability and chromosome stability. Hemann MT, Strong MA, Hao LY, Greider CW in Cell 2001 Oct 5;107(1):67-77
[63b] Hayflick, his limit, and cellular ageing. Shay JW, Wright WE in Nat Rev Mol Cell Biol 2000 Oct;1(1):72-6
[63c] Accelerated telomere shortening in fibroblasts after extended periods of confluency. Sitte N, Saretzki G, von Zglinicki T in Free Radic Biol Med 1998 Apr;24(6):885-93
[63d] Accelerated telomere shortening in Fanconi anemia fibroblasts - a longitudinal study. Adelfalk C, Lorenz M, Serra V, von Zglinicki T, Hirsch-Kauffmann M, Schweiger M in FEBS Lett 2001 Sep 28;506(1):22-6
[63e] Age-dependent telomere shortening is slowed down by enrichment of intracellular vitamin C via suppression of oxidative stress. Furumoto K, Inoue E, Nagao N, Hiyama E, Miwa N in Life Sci 1998;63(11):935-48
[63f] Telomere reduction in human liver tissues with age and chronic inflammation. Aikata H, Takaishi H, Kawakami Y, Takahashi S, Kitamoto M, Nakanishi T, Nakamura Y, Shimamoto F, Kajiyama G, Ide T in Exp Cell Res 2000 May 1;256(2):578-82
[64a] Does p53 affect organismal aging? Donehower LA in J Cell Physiol 2002 Jul;192(1):23-33
[64b] p53 mutant mice that display early ageing-associated phenotypes. Tyner SD, Venkatachalam S, Choi J, Jones S, Ghebranious N, Igelmann H, Lu X, Soron G, Cooper B, Brayton C, Hee Park S, Thompson T, Karsenty G, Bradley A, Donehower LA in Nature 2002 Jan 3;415(6867):45-53
[64c] Selenomethionine regulation of p53 by a ref1-dependent redox mechanism. Seo YR, Kelley MR, Smith ML in Proc Natl Acad Sci U S A 2002 Sep 30; [epub ahead of print]
"selenium in the form of selenomethionine (SeMet) can activate the p53 tumor suppressor protein by a redox mechanism that requires the redox factor Ref1. Assays to measure direct reduction/oxidation of p53 showed a SeMet-dependent response that was blocked by a dominant-negative Ref1. […] The evidence suggests that the DNA repair branch of the p53 pathway was activated. The central relevance of DNA repair to cancer prevention is discussed."
[64d] The selenium metabolite selenodiglutathione induces p53 and apoptosis: relevance to the chemopreventive effects of selenium? Lanfear J, Fleming J, Wu L, Webster G, Harrison PR in Carcinogenesis 1994 Jul;15(7):1387-92
[64e] p53 regulation of DNA excision repair pathways. Smith ML, Seo YR in Mutagenesis 2002 Mar;17(2):149-56
"The regulation of DNA excision repair pathways by p53 and its downstream genes is an emerging body of literature, largely distinct and separable from the more-studied cell cycle arrest and apoptosis responses regulated by p53. Regulation of nucleotide excision repair of UV-damage by p53 and its downstream genes Gadd45 and p48XPE has been well-documented, but much remains to be done in elucidating mechanisms. Moreover, p53 also participates in base excision repair of hydrogen peroxide-induced damage, still at an early stage of investigation."
[64f] A role for p53 in maintaining and establishing the quiescence growth arrest in human cells. Itahana K, Dimri GP, Hara E, Itahana Y, Zou Y, Desprez PY, Campisi J in J Biol Chem 2002 May 17;277(20):18206-14
[65] Heterogeneity and its biodemographic implications for longevity and mortality. Carnes BA, Olshansky SJ in Exp Gerontol 2001 Mar;36(3):419-30
[66] Phase II randomized clinical trial of lycopene supplementation before radical prostatectomy. Kucuk O, Sarkar FH, Sakr W, Djuric Z, Pollak MN, Khachik F, Li YW, Banerjee M, Grignon D, Bertram JS, Crissman JD, Pontes EJ, Wood DP Jr in Cancer Epidemiol Biomarkers Prev 2001 Aug;10(8):861-8
[67] Effects of lycopene and Sho-saiko-to on hepatocarcinogenesis in a rat model of spontaneous liver cancer. Watanabe S, Kitade Y, Masaki T, Nishioka M, Satoh K, Nishino H in Nutr Cancer 2001;39(1):96-101
[68a] Dehydroepiandrosterone is a complete hepatocarcinogen and potent tumor promoter in the absence of peroxisome proliferation in rainbow trout. Orner GA, Mathews C, Hendricks JD, Carpenter HM, Bailey GS, Williams DE in Carcinogenesis 1995 Dec;16(12):2893-8
[68b] Dietary intervention at middle age: caloric restriction but not dehydroepiandrosterone sulfate increases lifespan and lifetime cancer incidence in mice. Pugh TD, Oberley TD, Weindruch R in Cancer Res 1999 Apr 1;59(7):1642-8
[68c] Lifelong treatment with oral DHEA sulfate does not preserve immune function, prevent disease, or improve survival in genetically heterogeneous mice. Miller RA, Chrisp C in J Am Geriatr Soc 1999 Aug;47(8):960-6
"There were no significant effects of DHEAS on incidence of lethal illnesses, except for a trend toward higher levels of mammary adenocarcinoma in DHEAS-treated females and mouse urinary syndrome in DHEAS-treated males. [….] our data provide no support for the idea that chronic exposure to this steroid retards immune senescence or prevents late life illness."
[69] The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study in Finland. Blumberg J, Block G in Nutr Rev 1994 Jul;52(7):242-5
[70] Lower prostate cancer risk in men with elevated plasma lycopene levels: results of a prospective analysis. Gann PH, Ma J, Giovannucci E, Willett W, Sacks FM, Hennekens CH, Stampfer MJ in Cancer Res 1999 Mar 15;59(6):1225-30 .
[71] Dietary antioxidant supplementation and DNA damage in smokers and nonsmokers. Welch RW, Turley E, Sweetman SF, Kennedy G, Collins AR, Dunne A, Livingstone MB, McKenna PG, McKelvey-Martin VJ, Strain JJ in Nutr Cancer 1999;34(2):167-72
[72a] All About Selenium. Richard A Passwater (1999) ISBN 0895299674
[72b] Nicotinamide and selenium stimulate the repair of DNA damage produced by N-nitrosobis (2-oxopropyl) amine. Lawson T in Anticancer Res 1989 Mar-Apr;9(2):483-6
[73] Encyclopedia of Nutritional Supplements. Michael T Murray, (1996) ISBN 0761504109 An invaluable resource; should be read by everybody prior to supplementing.
[74] Biotransformation of curcumin through reduction and glucuronidation in mice. Pan MH, Huang TM, Lin JK in Drug Metab Dispos 1999 Apr;27(4):486-94
[75] Water, other fluids, and fatal coronary heart disease: the Adventist Health Study. Chan J, Knutsen SF, Blix GG, Lee JW, Fraser GE in Am J Epidemiol 2002 May 1;155(9):827-33
[76] Improved thermoregulation caused by forced water intake in human desert dwellers. Kristal-Boneh E, Glusman JG, Chaemovitz C, Cassuto Y in Eur J Appl Physiol Occup Physiol 1988;57(2):220-4
[77] Your Personal Vitamin Profile. Michael Colgan, (1982) ISBN 0-85634-140-1
[78a] Preventing Cancers edited. T Heller, L Bailey & S Pattison (1992) ISBN 0335190030. Page 116/7 documents the relationship between smoking duration/intensity, age and cancer risk.
[78b] Smoking, smoking cessation, and lung cancer in the UK since 1950: combination of national statistics with two case-control studies. Peto R, Darby S, Deo H, Silcocks P, Whitley E, Doll R in BMJ 2000 Aug 5;321(7257):323-9
"The cumulative risks by 75 years of age are 15.9% for men who continue to smoke cigarettes and 9.9%, 6.0%, 3.0%, and 1.7% for those who stopped around 60, 50, 40, and 30 years of age." Never smoked = 0.4%
[78c] Mortality in relation to smoking: 40 years' observations on male British doctors. Doll R, Peto R, Wheatley K, Gray R, Sutherland I in BMJ 1994 Oct 8;309(6959):901-11
"The death rate ratios during 1971-91 (comparing continuing cigarette smokers with life-long non-smokers) were approximately threefold at ages 45-64 and twofold at ages 65-84. The excess mortality was chiefly from diseases that can be caused by smoking. Positive associations with smoking were confirmed for death from cancers of the mouth, oesophagus, pharynx, larynx, lung, pancreas, and bladder; from chronic obstructive pulmonary disease and other respiratory diseases; from vascular diseases; from peptic ulcer; […] It now seems that about half of all regular cigarette smokers will eventually be killed by their habit."
[78d] Cigarette smoking and mortality. MRFIT Research Group. Kuller LH, Ockene JK, Meilahn E, Wentworth DN, Svendsen KH, Neaton JD in Prev Med 1991 Sep;20(5):638-54
"Overall, approximately one-half of all deaths were associated with cigarette smoking. [….] There was no evidence that lung cancer death rates were lower among cigarette smokers who quit compared with those who continued to smoke in this 10-year follow-up period. CONCLUSION. The data are consistent with results of previous epidemiologic studies indicating that the benefits of smoking cessation on CHD [coronary heart disease] are rapid, while for lung cancer, the benefit is not evident in a 10-year follow-up period."
[78e] Mortality in relation to smoking history: 13 years' follow-up of 68,000 Norwegian men and women 35-49 years. Tverdal A, Thelle D, Stensvold I, Leren P, Bjartveit K in J Clin Epidemiol 1993 May;46(5):475-87
"Among men who had quit cigarette smoking, the coronary heart disease mortality decreased with time since quitting to almost the level of the never cigarette smokers after 5 years or more."
[78f] Decline in the risk of myocardial infarction among women who stop smoking. Rosenberg L, Palmer JR, Shapiro S in N Engl J Med 1990 Jan 25;322(4):213-7
"These data suggest that in women, as in men, the increase in the risk of a first myocardial infarction among cigarette smokers declines soon after the cessation of smoking and is largely dissipated after two or three years."
[78g] Cohort analysis of cigarette smoking and lung cancer incidence among Norwegian women. Haldorsen T, Grimsrud TK in Int J Epidemiol 1999 Dec;28(6):1032-6
"For both current smokers and former smokers, the excess risk was about proportional to the daily amount smoked and the 4.5 power of duration of smoking. The age-specific rates for non-smokers were close to a fifth-power curve of age."
[79a] Elevated plasma homocysteine levels in centenarians are not associated with cognitive impairment. Ravaglia G, Forti P, Maioli F, Vettori C, Grossi G, Bargossi AM, Caldarera M, Franceschi C, Facchini A, Mariani E, Cavalli G in Mech Ageing Dev 2000 Dec 20;121(1-3):251-61
"Demented centenarians had the lowest folate serum levels."
[79b] Homocysteine, vitamin B6, and vascular disease in AD patients. Miller JW, Green R, Mungas DM, Reed BR, Jagust WJ in Neurology 2002 May 28;58(10):1471-5
"Elevated plasma homocysteine in patients with AD appears related to vascular disease and not AD pathology. In addition, low vitamin B(6) status is prevalent in patients with AD."
[80] An interspecies prediction of the risk of radiation-induced mortality. Carnes BA, Olshansky SJ, Grahn D in Radiat Res 1998 May;149(5):487-92
[81a] Allometric scaling of metabolic rate from molecules and mitochondria to cells and mammals. West GB, Woodruff WH, Brown JH in Proc Natl Acad Sci U S A 2002 Feb 19;99 Suppl 1:2473-8
[81b] Allometric scaling in animals and plants. Dreyer O, Puzio R in J Math Biol 2001 Aug;43(2):144-56
[81c] Nevill's explanation of Kleiber's 0.75 mass exponent: an artifact of collinearity problems in least squares models? Batterham AM, Tolfrey K, George KP in J Appl Physiol 1997 Feb;82(2):693-7 Comment in: J Appl Physiol. 1997 Dec;83(6):2167-8.
[82a] Vitamins for chronic disease prevention in adults: clinical applications. Fletcher RH, Fairfield KM in JAMA 2002 Jun 19;287(23):3127-9
"Most people do not consume an optimal amount of all vitamins by diet alone. Pending strong evidence of effectiveness from randomized trials, it appears prudent for all adults to take vitamin supplements.[….] We recommend that all adults take one multivitamin daily.[…..] It is reasonable to consider a dose of 2 ordinary [i.e. RDA levels] multivitamins daily in the elderly"
[82b] Vitamins for chronic disease prevention in adults: scientific review. Fairfield KM, Fletcher RH in JAMA 2002 Jun 19;287(23):3116-26
"Although the clinical syndromes of vitamin deficiencies are unusual in Western societies, suboptimal vitamin status is not [unusual]."
[83a] Ageing and diabetes: implications for brain function. Biessels GJ, van der Heide LP, Kamal A, Bleys RL, Gispen WH in Eur J Pharmacol 2002 Apr 19;441(1-2):1-14
[83b] The Maillard hypothesis on aging: time to focus on DNA. Baynes JW in Ann N Y Acad Sci 2002 Apr;959:360-7
[83c] Factors of skin ageing share common mechanisms. Giacomoni PU, Rein G in Biogerontology 2001;2(4):219-29
[83d] Protein glycation, diabetes, and aging. Ulrich P, Cerami A in Recent Prog Horm Res 2001;56:1-21
[83e] [Non-enzymic glycation and oxidative stress in chronic illnesses and diabetes mellitus] Nawroth PP, Bierhaus A, Vogel GE, Hofmann MA, Zumbach M, Wahl P, Ziegler R in Med Klin 1999 Jan 15;94(1):29-38
[83f] Receptors for proteins modified by advanced glycation endproducts (AGE)--their functional role in atherosclerosis. Sano H, Nagai R, Matsumoto K, Horiuchi S in Mech Ageing Dev 1999 Mar 15;107(3):333-46
[83g] An overview of carbohydrate-protein interactions with specific reference to myosin and ageing. Ramamurthy B, H]o]ok P, Larsson L in Acta Physiol Scand 1999 Dec;167(4):327-9
[83h] AGEs and their interaction with AGE-receptors in vascular disease and diabetes mellitus. I. The AGE concept. Bierhaus A, Hofmann MA, Ziegler R, Nawroth PP in Cardiovasc Res 1998 Mar;37(3):586-600
[83i] The effects of ageing on glycation and the interpretation of glycaemic control in Type 2 diabetes. Kilpatrick ES, Dominiczak MH, Small M in QJM 1996 Apr;89(4):307-12
"In 232 non-diabetics, there was a linear relationship between HbA1C and age (r = 0.49, p < 0.0001). Mean HbA1C rose from 3.82% to 4.44% between the ages of 20 and 70."
[84a] [Biosynthesis of group B vitamins by yeasts--symbionts of xylophagous insects] Gusteleva LA in Mikrobiologiia 1975 Jan-Feb;44(1):45-7
[84b] Mycetocyte symbiosis in insects. Douglas AE in Biol Rev Camb Philos Soc 1989 Nov;64(4):409-34
[85] Safety of high-dose nicotinamide: a review. Knip M, Douek IF, Moore WP, Gillmor HA, McLean AE, Bingley PJ, Gale EA in Diabetologia 2000 Nov;43(11):1337-45
Discusses the potential vitamin B3 in preventing the onset of Type I (insulin-dependent) diabetes.
[86a] A synergistic effect of a daily supplement for 1 month of 200 mg magnesium plus 50 mg vitamin B6 for the relief of anxiety-related premenstrual symptoms: a randomized, double-blind, crossover study. De Souza MC, Walker AF, Robinson PA, Bolland K in J Womens Health Gend Based Med 2000 Mar;9(2):131-9
"no overall difference between individual treatments, but predefined treatment comparisons using factorial contrasts in ANOVA showed a significant effect of 200 mg/day Mg + 50 mg/day vitamin B6 on reducing anxiety-related premenstrual symptoms (nervous tension, mood swings, irritability, or anxiety) (p = 0.040). Urinary Mg output was not affected by treatment. A small synergistic effect of a daily dietary supplementation with a combination of Mg + vitamin B6 in the reduction of mild premenstrual anxiety-related symptoms was demonstrated during treatment of 44 women for one menstrual cycle."
[86b] Vitamin B6, magnesium, and combined B6-Mg: therapeutic effects in childhood autism. Martineau J, Barthelemy C, Garreau B, Lelord G in Biol Psychiatry 1985 May;20(5):467-78
"The behavioral improvement observed with the combination vitamin B6-magnesium was associated with significant modifications of both biochemical and electrophysiological parameters: the urinary HVA excretion decreased, and EP amplitude and morphology seemed to be normalized. These changes were not observed when either vitamin B6 or magnesium was administered alone."
[86c] Effect of combined supplementation of magnesium oxide and pyridoxine in calcium-oxalate stone formers. Rattan V, Sidhu H, Vaidyanathan S, Thind SK, Nath R in Urol Res 1994;22(3):161-5
"The results confirmed the efficacy of MgO-pyridoxine supplementation in terms of changes in urinary excretion of lithogenic and inhibitory components, leading to a significant (P < 0.01) decrease in CaOx risk index from 0.09 +/- 0.04 at 0 day to 0.05 +/- 0.02 after 120 days of treatment."
[87] The reliability theory of aging and longevity. Gavrilov LA, Gavrilova NS in J Theor Biol 2001 Dec 21;213(4):527-45
[88a] Amadorins: novel post-Amadori inhibitors of advanced glycation reactions. Khalifah RG, Baynes JW, Hudson BG in Biochem Biophys Res Commun 1999 Apr 13;257(2):251-8
[88b] Glycoxidation and lipoxidation in atherogenesis. Baynes JW, Thorpe SR in Free Radic Biol Med 2000 Jun 15;28(12):1708-16
[88c] [Diabetes and vitamin levels] Tamai H in Nippon Rinsho 1999 Oct;57(10):2362-5
[88d] In vitro kinetic studies of formation of antigenic advanced glycation end products (AGEs). Novel inhibition of post-Amadori glycation pathways. Booth AA, Khalifah RG, Todd P, Hudson BG in J Biol Chem 1997 Feb 28;272(9):5430-7
[88e] Thiamine pyrophosphate and pyridoxamine inhibit the formation of antigenic advanced glycation end-products: comparison with aminoguanidine. Booth AA, Khalifah RG, Hudson BG in Biochem Biophys Res Commun 1996 Mar 7;220(1):113-9
"Among the inhibitors, pyridoxamine and thiamine pyrophosphate potently inhibited AGE formation and were more effective than aminoguanidine, suggesting that these two compounds may have novel therapeutic potential in preventing vascular complications of diabetes."
[89] A prospective study of the intake of vitamins C and B6, and the risk of kidney stones in men. Curhan GC, Willett WC, Rimm EB, Stampfer MJ in J Urol 1996 Jun;155(6):1847-51
[90] Exercise-induced changes in immune function: effects of zinc supplementation. Singh A, Failla ML, Deuster PA in J Appl Physiol 1994 Jun;76(6):2298-303
[91] Laurie Barclay, MD Reviewed. Gary D. Vogin, MD from the American Diabetes Association Annual Meeting: Abstracts 1644-P, 569-P. June 16-17, 2002,
"In a separate study by Dilina N. Marreiro and colleagues from Universidade de Sao Paulo-SP in Brazil, zinc supplementation enhanced insulin sensitivity in obese women who were not zinc-deficient."
[92] Ubiquitous overexpression of CuZn superoxide dismutase does not extend life span in mice. Huang TT, Carlson EJ, Gillespie AM, Shi Y, Epstein CJ in J Gerontol A Biol Sci Med Sci 2000 Jan;55(1):B5-9
[93a] Urinary biotin analogs increase in humans during chronic supplementation: the analogs are biotin metabolites. Mock DM, Heird GM in Am J Physiol 1997 Jan;272(1 Pt 1):E83-5
[93b] Biotin supplementation improves glucose and insulin tolerances in genetically diabetic KK mice. Reddi A, DeAngelis B, Frank O, Lasker N, Baker H Life Sci 1988;42(13):1323-30
[93c] Oral glucose tolerance test after high-dose i.v. biotin administration in normoglucemic hemodialysis patients. Koutsikos D, Fourtounas C, Kapetanaki A, Agroyannis B, Tzanatos H, Rammos G, Kopelias I, Bosiolis B, Bovoleti O, Darema M, Sallum G in Ren Fail 1996 Jan;18(1):131-7
[93d] [Enhancement of glucose-induced insulin secretion and modification of glucose metabolism by biotin] Furukawa Y in Nippon Rinsho 1999 Oct;57(10):2261-9
[93e] Biotin administration improves the impaired glucose tolerance of streptozotocin-induced diabetic Wistar rats. Zhang H, Osada K, Sone H, Furukawa Y in J Nutr Sci Vitaminol (Tokyo) 1997 Jun;43(3):271-80
[93f] A high biotin diet improves the impaired glucose tolerance of long-term spontaneously hyperglycemic rats with non-insulin-dependent diabetes mellitus. Zhang H, Osada K, Maebashi M, Ito M, Komai M, Furukawa Y in J Nutr Sci Vitaminol (Tokyo) 1996 Dec;42(6):517-26
[94] I’m indebted to John de Rivaz for this observation.
[95a] Aging and mortality: manifestations of increasing informational entropy of the genome? Riggs JE in Mech Ageing Dev 1993 Jan;66(3):249-56
[95b] DNA damage as the primary cause of aging. Gensler HL, Bernstein H in Q Rev Biol 1981 Sep;56(3):279-303
[95c] Age-related changes of accuracy and efficiency of protein synthesis machinery in rat. Mariotti D, Ruscitto R in Biochim Biophys Acta 1977 Mar 2;475(1):96-102
[96a] Skin cancer chemoprevention. Mukhtar H, Agarwal R in J Investig Dermatol Symp Proc 1996 Apr;1(2):209-14
[96b] Colon cancer chemoprevention with ginseng and other botanicals. Wargovich MJ in J Korean Med Sci 2001 Dec;16 Suppl:S81-6
[96c] Chemoprevention of bladder cancer. Kamat AM, Lamm DL in Urol Clin North Am 2002 Feb;29(1):157-68
"There is a mistaken notion that simply because an agent is naturally occurring, it cannot be as beneficial as taking a substance synthesized in the laboratory."
[96d] Antimicrobial properties of Allium sativum (garlic). Harris JC, Cottrell SL, Plummer S, Lloyd D in Appl Microbiol Biotechnol 2001 Oct;57(3):282-6
[96e] Current concepts in optimum nutrition for cardiovascular disease. Platt R in Prev Cardiol 2000 Spring;3(2):83-87
[96f] Phytochemicals: guardians of our health. Craig WJ in J Am Diet Assoc 1997 Oct;97(10 Suppl 2):S199-204
[96h] Mechanisms by which garlic and allyl sulfur compounds suppress carcinogen bioactivation. Garlic and carcinogenesis. Milner JA in Adv Exp Med Biol 2001;492:69-81
[97a] A prospective study of folate intake and the risk of breast cancer. Zhang S, Hunter DJ, Hankinson SE, Giovannucci EL, Rosner BA, Colditz GA, Speizer FE, Willett WC in JAMA 1999 May 5;281(17):1632-7
[97b] Dietary folate intake, alcohol, and risk of breast cancer in a prospective study of postmenopausal women. Sellers TA, Kushi LH, Cerhan JR, Vierkant RA, Gapstur SM, Vachon CM, Olson JE, Therneau TM, Folsom AR in Epidemiology 2001 Jul;12(4):420-8
[98] Alpha-lipoic acid as a new treatment option for Azheimer type dementia. Hager K, Marahrens A, Kenklies M, Riederer P, Munch G in Arch Gerontol Geriatr 2001 Jun;32(3):275-282
"600 mg alpha-lipoic acid was given daily to nine patients with AD and related dementias […] The treatment led to a stabilization of cognitive functions in the study group"
[99] Cross-talk between iron metabolism and diabetes. Fernandez-Real JM, Lopez-Bermejo A, Ricart W in Diabetes 2002 Aug;51(8):2348-54
[100] Intake of selected micronutrients and risk of colorectal cancer. La Vecchia C, Braga C, Negri E, Franceschi S, Russo A, Conti E, Falcini F, Giacosa A, Montella M, Decarli A in Int J Cancer 1997 Nov 14;73(4):525-30
"For most micronutrients, ORs [odds ratios] were below unity with increasing quintile of intake. The most consistent protective effects were for carotene, riboflavin and vitamin C […] Inverse relationships were observed also for calcium and vitamin D (ORs of 0.85 and 0.93, respectively). When the combined effect of calcium and vitamin D and selected anti-oxidants was considered, the OR reached 0.46 in subjects reporting high calcium/vitamin D and high anti-oxidant intake compared to those reporting low intake of both groups of micronutrients."
[101a] Serum and cerebrospinal fluid vitamin B12 levels in demented patients with CH3-B12 treatment--preliminary study. Mitsuyama Y, Kogoh H in Jpn J Psychiatry Neurol 1988 Mar;42(1):65-71
"The serum and CSF-VB12 levels of the demented patients did not show any significant elevation after the oral administration of CH3-B12, 2 mg per day. On the other hand, there was a marked elevation of both the serum and CSF-VB12 after an oral medication (2 mg per day) plus intramuscular administrations (500 micrograms per day)."
[101b] [Effects of mecobalamin on testicular dysfunction induced by X-ray irradiation in mice] Oshio S, Yazaki T, Umeda T, Ozaki S, Ohkawa I, Tajima T, Yamada T, Mohri H in Nippon Yakurigaku Zasshi 1991 Dec;98(6):483-90
Human equivalent oral dose of 10mg/d of methylcobalamin was effective, 1mg/d ineffective.
[102] [Effect of riboflavin (vitamin B2) on spontaneous gonarthrosis in the mouse] Wilhelmi G, Tanner K in in Z Rheumatol 1988 May-Jun;47(3):166-72
[103] B-vitamin supplementation of diets for feedlot calves. Zinn RA, Owens FN, Stuart RL, Dunbar JR, Norman BB in J Anim Sci 1987 Jul;65(1):267-77
"B-vitamin supplementation of diets for 144 shipping-stressed crossbred calves (116 kg) at levels up to 10 times that recommended for growing pigs did not influence (P greater than .20) weight gain or feed conversion during a 56-d receiving trial. However, [the extra] vitamin supplementation tended (P less than .10) to reduce morbidity."
[104a] Treatment of Alzheimer-type dementia with intravenous mecobalamin. Ikeda T, Yamamoto K, Takahashi K, Kaku Y, Uchiyama M, Sugiyama K, Yamada M in Clin Ther 1992 May-Jun;14(3):426-37
"We conclude that mecobalamin is a safe and effective treatment for psychiatric disorders in patients with Alzheimer-type dementia."
[104b] Vitamin B12 deficiency and dementia. Cunha UG, Rocha FL, Peixoto JM, Motta MF, Barbosa MT in Int Psychogeriatr 1995 Spring;7(1):85-8
"All of the patients who showed some improvement (MMSE returned to normal values) had mild dementia with a history of less than 2 years. Thus, screening for B12 deficiency should be considered in patients with recent onset of mild mental status changes."
[104c] Treatment of cobalamin deficiency in dementia, evaluated clinically and with cerebral blood flow measurements. Nilsson K, Warkentin S, Hultberg B, Faldt R, Gustafson L in Aging (Milano) 2000 Jun;12(3):199-207
"Fifteen patients who showed mild to moderate dementia improved clinically, and also showed a concomitant increase in their general CBF after treatment. In contrast, 9 patients who were severely demented showed no obvious clinical improvement, and no general blood flow change, although some regional flow increases were seen in sensory motor areas."
[104d] Effects of vitamin B12 on bright light on cognitive and sleep-wake rhythm in Alzheimer-type dementia. Ito T, Yamadera H, Ito R, Suzuki H, Asayama K, Endo S in ] Psychiatry Clin Neurosci 2001 Jun;55(3):281-2
"These results suggest that VB12 has some efficiency to enhance vigilance for ATD patients."
[104e] The frequently low cobalamin levels in dementia usually signify treatable metabolic, neurologic and electrophysiologic abnormalities. Carmel R, Gott PS, Waters CH, Cairo K, Green R, Bondareff W, DeGiorgio CM, Cummings JL, Jacobsen DW, Buckwalter G, et al in Eur J Haematol 1995 Apr;54(4):245-53
"Although the long-standing dementia does not improve, treating such patients with cobalamin has other concrete benefits."
[105a] Double-blind, placebo controlled study of acetyl-l-carnitine in patients with Alzheimer's dementia. Rai G, Wright G, Scott L, Beston B, Rest J, Exton-Smith AN in Curr Med Res Opin 1990;11(10):638-47
"The results suggest that acetyl-l-carnitine may have a beneficial effect on some clinical features of Alzheimer-type dementia, particularly those related to short-term memory."
[105b] Acetyl-L-carnitine: a drug able to slow the progress of Alzheimer's disease? Carta A, Calvani M in Ann N Y Acad Sci 1991;640:228-32
"A review of a series of controlled clinical studies suggests that ALC may also slow the natural course of AD."
[105c] Long-term acetyl-L-carnitine treatment in Alzheimer's disease. Spagnoli A, Lucca U, Menasce G, Bandera L, Cizza G, Forloni G, Tettamanti M, Frattura L, Tiraboschi P, Comelli M, et al in Neurology 1991 Nov;41(11):1726-32
"In a double-blind, placebo-controlled, parallel-group, randomized clinical trial, we studied the efficacy of long-term (1-year) oral treatment with acetyl-L-carnitine in 130 patients with a clinical diagnosis of Alzheimer's disease. […] Adjusting for initial scores with analysis of covariance, the treated group showed better scores on all outcome measures, reaching statistical significance"
[105d] Double-blind parallel design pilot study of acetyl levocarnitine in patients with Alzheimer's disease. Sano M, Bell K, Cote L, Dooneief G, Lawton A, Legler L, Marder K, Naini A, Stern Y, Mayeux R in Arch Neurol 1992 Nov;49(11):1137-41
"These results suggest that acetyl levocarnitine may retard the deterioration in some cognitive areas in patients with Alzheimer's disease"
[105e] Clinical and neurochemical effects of acetyl-L-carnitine in Alzheimer's disease. Pettegrew JW, Klunk WE, Panchalingam K, Kanfer JN, McClure RJ in Neurobiol Aging 1995 Jan-Feb;16(1):1-4
"Compared to AD patients on placebo, acetyl-L-carnitine-treated patients showed significantly less deterioration in their Mini-Mental Status and Alzheimer's Disease Assessment Scale test scores. […] This is the first direct in vivo demonstration of a beneficial effect of a drug on both clinical and CNS neurochemical parameters in AD."
[105f] A 1-year multicenter placebo-controlled study of acetyl-L-carnitine in patients with Alzheimer's disease. Thal LJ, Carta A, Clarke WR, Ferris SH, Friedland RP, Petersen RC, Pettegrew JW, Pfeiffer E, Raskind MA, Sano M, Tuszynski MH, Woolson RF in Neurology 1996 Sep;47(3):705-11
"The study suggests that a subgroup of AD patients aged 65 or younger may benefit from treatment with ALCAR whereas older individuals might do more poorly."
[105g] Acetyl L-carnitine slows decline in younger patients with Alzheimer's disease: a reanalysis of a double-blind, placebo-controlled study using the trilinear approach. Brooks JO 3rd, Yesavage JA, Carta A, Bravi D in Int Psychogeriatr 1998 Jun;10(2):193-203
"ALC slows the progression of Alzheimer's disease in younger subjects [age<61], and the use of the trilinear approach to estimate the average rate of change may prove valuable in pharmacological trials."
[105h] Acetyl-L-carnitine physical-chemical, metabolic, and therapeutic properties: relevance for its mode of action in Alzheimer's disease and geriatric depression. Pettegrew JW, Levine J, McClure RJ in Mol Psychiatry 2000 Nov;5(6):616-32
"ALCAR is reported in double-blind controlled studies to have beneficial effects in major depressive disorders and Alzheimer's disease (AD)"
[106a] Thiamine and Alzheimer's disease. A pilot study. Blass JP, Gleason P, Brush D, DiPonte P, Thaler H in Arch Neurol 1988 Aug;45(8):833-5
"Global cognitive rating by the Mini-Mental State Examination was higher during three months with 3 g/d of oral thiamine hydrochloride than with niacinamide placebo. Behavioral ratings, however, did not differ significantly, nor did clinical state when it was judged subjectively."
[106b] Preliminary findings of high-dose thiamine in dementia of Alzheimer's type. Meador K, Loring D, Nichols M, Zamrini E, Rivner M, Posas H, Thompson E, Moore E in J Geriatr Psychiatry Neurol 1993 Oct-Dec;6(4):222-9
"we examined the effects of 3 to 8 g/day thiamine administered orally. Our results suggest that thiamine at these pharmacologic dosages may have a mild beneficial effect in dementia of Alzheimer's type."
[106c] Thiamine therapy in Alzheimer's disease. Mimori Y, Katsuoka H, Nakamura S in Metab Brain Dis 1996 Mar;11(1):89-94
"Only mildly impaired subjects showed cognitive improvement. Alzheimer patients' blood levels of thiamine before the trial were within the normal range."
[106d] Brain thiamine, its phosphate esters, and its metabolizing enzymes in Alzheimer's disease. Mastrogiacoma F, Bettendorff L, Grisar T, Kish SJ in Ann Neurol 1996 May;39(5):585-91
"Clinical data suggest that high-dose thiamine (vitamin B1) may have a mild beneficial effect in some patients with Alzheimer's disease (AD). [....] The TDP decrease could be explained by a cerebral cortical deficiency in AD of ATP, which is needed for TDP synthesis."
[106e] Low thiamine diphosphate levels in brains of patients with frontal lobe degeneration of the non-Alzheimer's type. Bettendorff L, Mastrogiacomo F, Wins P, Kish SJ, Grisar T, Ball MJ in J Neurochem 1997 Nov;69(5):2005-10
"We compared the thiamine and thiamine phosphate contents in the frontal, temporal, parietal, and occipital cortex of six patients with frontal lobe degeneration of the non-Alzheimer's type (FNAD) or frontotemporal dementia […] These results suggest that decreased contents of TDP, which is essentially mitochondrial, is a specific feature of FNAD. As TDP is an essential cofactor for oxidative metabolism and neurotransmitter synthesis, and because low thiamine status (compared with other species) is a constant feature in humans, a nearly 50% decrease in cortical TDP content may contribute significantly to the clinical symptoms observed in FNAD. This study also provides a basis for a trial of thiamine, to improve the cognitive status of the patients."
[107] Improvement of cognitive functions after cobalamin/folate supplementation in elderly patients with dementia and elevated plasma homocysteine. Nilsson K, Gustafson L, Hultberg B in Int J Geriatr Psychiatry 2001 Jun;16(6):609-14
"Patients with mild-moderate dementia and elevated plasma homocysteine levels improved clinically with increased test scores after vitamin substitution, while severely demented patients and patients with normal plasma homocysteine levels did not improve clinically."
[108a] Intake of flavonoids and risk of dementia. Commenges D, Scotet V, Renaud S, Jacqmin-Gadda H, Barberger-Gateau P, Dartigues JF in Eur J Epidemiol 2000 Apr;16(4):357-63
"We conclude that the intake of antioxidant flavonoids is inversely related to the risk of incident dementia."
[108b] Cancer preventive effects of flavonoids--a review. Le Marchand L in Biomed Pharmacother 2002 Aug;56(6):296-301
"A cancer protective effect from plant-derived foods has been found with uncommon consistency in epidemiologic studies. […] In recent years, experimental studies have provided growing evidence for the beneficial action of flavonoids on multiple cancer-related biological pathways (carcinogen bioactivation, cell-signaling, cell cycle regulation, angiogenesis, oxidative stress, inflammation)."
[109] Life Extension: A Practical Scientific Approach. Durk Pearson & Sandy Shaw (1982). ISBN 0446879908. Concentrates on free-radicals. Got me started on dietary supplements.
[110a]Effect of riboflavin supplementation on zinc and iron absorption and growth performance in mice. Agte VV, Paknikar KM, Chiplonkar SA in Biol Trace Elem Res 1998 Nov;65(2):109-15
"Percent zinc absorption, for the low-riboflavin diet, the supplemented diet, and the synthetic control diet were 16.4+/-5.7, 33.7+/-8.9, and 44.6+/-4.0, respectively, indicating the beneficial effect of riboflavin supplementation on iron and zinc utilization."
[110b] Single versus multiple deficiencies of methionine, zinc, riboflavin, vitamin B-6 and choline elicit surprising growth responses in young chicks. Baker DH, Edwards HM 3rd, Strunk CS, Emmert JL, Peter CM, Mavromichalis I, Parr TM in J Nutr 1999 Dec;129(12):2239-45
"A soy-protein isolate diet that was deficient in methionine (Met), zinc (Zn), riboflavin, vitamin B-6 and choline for chick growth (Assay 1) was used to study individual or multiple deficiencies of several of these nutrients. In all cases, adding all three deficient nutrients together resulted in growth responses that were superior to those resulting from supplementation with any pairs of deficient nutrients."
[110c] [Effects of riboflavin administration on vitamin B6 metabolism] Kodentsova VM, Iakushina LM, Vrzhesinskaia OA, Beketova NA, Spirichev VB in Vopr Pitan 1993 Oct-Dec;(5):32-6
[110d] [The effect of riboflavin supply on metabolism of water-soluble vitamins] Kodentsova VM, Vrzhesinskaia OA, Sokol'nikov AA, Beketova NA, Spirichev VB in Vopr Med Khim 1993 Sep-Oct;39(5):29-33
"Increase of vitamin B6 derivatives by 36% in liver tissue, decrease in content of thiamine by 20%, of ascorbic acid--by 35%, of oxidized nicotinamide coenzymes--by 27%, […] This suggests that evaluation of pyridoxine and/or niacin deficiency in food ration should be related with the rate of riboflavin consumption."
[111] Interaction among niacin, vitamin B6 and zinc in rats receiving ethanol. Vannucchi H, Kutnink MD, Sauberlich M, Howerde E in Int J Vitam Nutr Res 1986;56(4):355-62
"The main conclusion is that zinc repletion per se caused activation of niacin metabolism, increasing the excretion of niacin metabolites. This emphasizes the role of zinc in the function of these vitamins."
[112] [Effect of pantothenate on indices related to cobalamin metabolism in vitamin B 12 deficiency] Moiseenok AG, Bud'ko TN, Sheibak VM in Vopr Pitan 1982 May-Jun;(3):48-51
"Ten-fold administration of cyanocobalamine (0.5 microgram/kg), calcium pantothenate (3.3 mg/kg) or of both the preparations concurrently removed the aforesaid disorders of cobalamine metabolism, with the most complete therapeutic effect being attained upon combined use of the vitamin preparations."
[113] [B group vitamin metabolism in duodenal ulcer disease, hypertension, and ischemic heart disease] Kodentsova VM, Vrzhesinskaia OA, Kharitonchik LA, Spirichev VB in Vopr Med Khim 1994 Mar-Apr;40(2):41-5
"deficiency in riboflavin caused considerable impairments of vitamin B6 and niacin metabolism."
[114a] [Effect of flavin coenzymes on the pyridoxine treatment of avitaminosis B6] Stroev EA, Kazakova NT in Vopr Pitan 1981 Jan-Feb;(1):43-5
[114b] [Effect of the combined use of flavin coenzyme preparations and pyridoxine on the body vitamin balance in animals] Stroev EA, Kazakova NT in Farmakol Toksikol 1980 Sep-Oct;43(5):601-3
[115a] Impaired functioning of thermolabile methylenetetrahydrofolate reductase is dependent on riboflavin status: implications for riboflavin requirements. McNulty H, McKinley MC, Wilson B, McPartlin J, Strain JJ, Weir DG, Scott JM in Am J Clin Nutr 2002 Aug;76(2):436-41
"The high tHcy concentration typically associated with homozygosity for the 677C-->T variant of MTHFR occurs only with poor riboflavin status." The mutant, thermolabile version of MTHFR, present in 10-15% of the European genotype renders the co-enzyme FAD prosthetic group ~10 times more likely to disassociate. Extra riboflavin stabilises MTHFR.
[115b] Riboflavin as a determinant of plasma total homocysteine: effect modification by the methylenetetrahydrofolate reductase C677T polymorphism. Hustad S, Ueland PM, Vollset SE, Zhang Y, Bjorke-Monsen AL, Schneede J in Clin Chem 2000 Aug;46(8 Pt 1):1065-71
"The riboflavin-tHcy relationship was modified by genotype (P = 0.004) and was essentially confined to subjects with the C677T transition of the MTHFR gene. CONCLUSIONS: Plasma riboflavin is an independent determinant of plasma tHcy."
[116a] Effect of dietary vitamin E on lipofuscin accumulation with age in the rat brain. Monji A, Morimoto N, Okuyama I, Yamashita N, Tashiro N in Brain Res 1994 Jan 14;634(1):62-8
"dietary vitamin E clearly had a significant effect on lipofuscin accumulation with age in the rat brain up until middle age, and that the same effect became indistinct in the latter half of their life."
[116b] Effects of vitamin E on the blastogenic response of splenocytes and lipofuscin contents in the hearts and brains of aged mice. Ma XY, Su YB, Zhang FR, Li JF in J Environ Pathol Toxicol Oncol 1996;15(1):51-3
"the lipofuscin level in the brains and hearts of aged mice declined substantially with the VE supplementation (heart: p < 0.001, brain: p < 0.05). Furthermore, the effects of dietary VE on the serum VE and tissue lipofuscin content in aged mice were much more obvious than in the young animals."
[116c] Lipofuscin accumulation and its prevention by vitamin E in nervous tissue: quantitative analysis using snail buccal ganglia as a simple model system. Winstanley EK, Pentreath VW in Mech Ageing Dev 1985 Mar;29(3):299-307
"This diet prevented lipofuscin appearance in the young animals, and reduced the lipofuscin content by 50% in the old animals. The findings provide direct evidence that Vitamin E reduces lipofuscin accumulation in glial cells in intact nervous tissue."
[116d] Long-term variations in cyclic light intensity and dietary vitamin A intake modulate lipofuscin content of the retinal pigment epithelium. Katz ML, Gao CL, Rice LM in J Neurosci Res 1999 Jul 1;57(1):106-16
"lipofuscin content is determined by a balance between the rates at which lipofuscin is formed and at which it is eliminated"
[116e] Increased plasma lipidperoxidation in vitamin B-6 deficient rats. Ravichandran V, Selvam R in Indian J Exp Biol 1991 Jan;29(1):56-8
"lipofuscin like pigments were increased in vitamin B-6 deficiency"
[116f] Tissue vitamin E levels and lipofuscin accumulation with age in the mouse. Blackett AD, Hall DA in J Gerontol 1981 Sep;36(5):529-33
"Vitamin E levels in the supplemented stock were found to be 4 X those of the controls although dietary intake was 250 X control. Lipofuscin levels of supplemented stock were lower than controls throughout the lifespan culminating at 28 months when the levels were consistent with the 23 month levels of the controls."
[117a] Melatonin suppresses iron-induced neurodegeneration in rat brain. Lin AM, Ho LT in Free Radic Biol Med 2000 Mar 15;28(6):904-11
"The antioxidative action of melatonin on iron-induced neurodegeneration in the nigrostriatal dopaminergic system was evaluated in vivo. [….] Our data suggest that melatonin is capable of at least partially preventing the iron-induced neurodegeneration in the nigrostriatal dopaminergic system."
[117b] Glutamate induces oxidative stress not mediated by glutamate receptors or cystine transporters: protective effect of melatonin and other antioxidants. Herrera F, Sainz RM, Mayo JC, Martin V, Antolin I, Rodriguez C in J Pineal Res 2001 Nov;31(4):356-62
[117c] Selective dopaminergic vulnerability: 3,4-dihydroxyphenylacetaldehyde targets mitochondria. Kristal BS, Conway AD, Brown AM, Jain JC, Ulluci PA, Li SW, Burke WJ in Free Radic Biol Med 2001 Apr 15;30(8):924-31
[117d] Neuroprotective effect of vitamin E on the early model of Parkinson's disease in rat: behavioral and histochemical evidence. Roghani M, Behzadi G in Brain Res 2001 Feb 16;892(1):211-7
"There is strong evidence that oxidative stress participates in the etiology of Parkinson's disease (PD). […] repeated intramuscular administration of vitamin E exerts a rapid protective effect on the nigrostriatal dopaminergic neurons in the early unilateral model of PD."
[117e] Vitamin D(3) attenuates 6-hydroxydopamine-induced neurotoxicity in rats. Wang JY, Wu JN, Cherng TL, Hoffer BJ, Chen HH, Borlongan CV, Wang Y in Brain Res 2001 Jun 15;904(1):67-75
[117f] Tissue distribution and neuroprotective effects of citrus flavonoids tangeretin in a rat model of Parkinson's disease. Datla KP, Christidou M, Widmer WW, Rooprai HK, Dexter DT in Neuroreport 2001 Dec 4;12(17):3871-5
"Neuroprotective effects of a natural antioxidant tangeretin, a citrus flavonoid, were elucidated in the 6-hydroxydopamine (6-OHDA) lesion rat model of Parkinson's disease (PD)[…]. The significant protection of striato-nigral integrity and functionality by tangeretin suggests its potential use as a neuroprotective agent."
[117g] The substantia nigra of the human brain. II. Patterns of loss of dopamine-containing neurons in Parkinson's disease. Damier P, Hirsch EC, Agid Y, Graybiel AM in Brain 1999 Aug;122 ( Pt 8):1437-48
[117h] The substantia nigra of the human brain. I. Nigrosomes and the nigral matrix, a compartmental organization based on calbindin D(28K) immunohistochemistry. Damier P, Hirsch EC, Agid Y, Graybiel AM in Brain 1999 Aug;122 ( Pt 8):1421-36
[118a] Effects of vitamin B12 on plasma melatonin rhythm in humans: increased light sensitivity phase-advances the circadian clock? Honma K, Kohsaka M, Fukuda N, Morita N, Honma S in Experientia 1992 Aug 15;48(8):716-20
[118b] Vitamin B12 treatment for sleep-wake rhythm disorders. Okawa M, Mishima K, Nanami T, Shimizu T, Iijima S, Hishikawa Y, Takahashi K in Sleep 1990 Feb;13(1):15-23
[118c] Circadian rhythm sleep disorders in adolescents: clinical trials of combined treatments based on chronobiology. Okawa M, Uchiyama M, Ozaki S, Shibui K, Ichikawa H in Psychiatry Clin Neurosci 1998 Oct;52(5):483-90
[119] Synergy literally means having an effect in combination greater than the sum of the effects separately. However synergy is often used, vernacularly, to mean having an effect in combination greater than any of the separate effects. Synergy is used here both literally and vernacularly.
[120] Calorie restriction extends Saccharomyces cerevisiae lifespan by increasing respiration. Lin SJ, Kaeberlein M, Andalis AA, Sturtz LA, Defossez PA, Culotta VC, Fink GR, Guarente L in Nature 2002 Jul 18;418(6895):344-8 Comment in: Nature. 2002 Jul 18;418(6895):287-8.
[121] Longevity of cold-exposed rats: a reevaluation of the "rate-of-living theory". Holloszy JO, Smith EK in J Appl Physiol 1986 Nov;61(5):1656-60
"The results of this study provide no support for the concept that increased energy expenditure decreases longevity."
[122a] Vitamin E--its significance in mouse ageing. Blackett AD, Hall DA in Age Ageing 1981 Aug;10(3):191-5
"An increase in mean but not maximum lifespan with vitamin E was attributable to fewer fatalities early in life."
[122b] Lack of an effect of vitamin E on lifespan of mice. Morley AA, Trainor KJ in Biogerontology 2001;2(2):109-12
[123a] Mitochondrial DNA repair of oxidative damage in mammalian cells. Bohr VA, Stevnsner T, de Souza-Pinto NC in Gene 2002 Mar 6;286(1):127-34
"Most of these small base modifications are repaired by the base excision repair (BER) pathway. Despite the initial concept that mitochondria lack DNA repair, experimental evidences now show that mitochondria are very proficient in BER of oxidative DNA damage, and proteins necessary for this pathway have been isolated from mammalian mitochondria. Here, we examine the BER pathway with an emphasis on mtDNA repair."
[123b] Mitochondrial DNA repair pathways. Bohr VA, Anson RM in J Bioenerg Biomembr 1999 Aug;31(4):391-8
"Mitochondrial DNA does not code for any DNA repair proteins, but it has been observed that a number of repair factors can be found in mitochondrial extracts. Most of these participate in the base excision DNA repair pathway which is responsible for the removal of simple lesions in DNA. Recent work has shown that there is efficient base excision repair in mammalian mitochondria and there are also indications of the presence of more complex repair processes."
[124] High-dose vitamin therapy stimulates variant enzymes with decreased coenzyme binding affinity (increased K(m)): relevance to genetic disease and polymorphisms. Ames BN, Elson-Schwab I, Silver EA in Am J Clin Nutr 2002 Apr;75(4):616-58
[125] Influence of lecithin on mitochondrial DNA and age-related hearing loss. Seidman MD, Khan MJ, Tang WX, Quirk WS in Otolaryngol Head Neck Surg 2002 Sep;127(3):138-44
"Lecithin is a polyunsaturated phosphatidylcholine (PPC), which are high energy functional and structural elements of all biologic membranes. PPC play a rate-limiting role in the activation of numerous membrane-located enzymes, [….]Flow cytometry revealed significantly higher mitochondrial membrane potentials in the treated subjects, suggesting preserved mitochondrial function. Finally, the common aging mitochondrial DNA deletion (mtDNA(4834)) were amplified from brain and cochlear tissue including stria vascularis and auditory nerve. This specific deletion was found significantly less frequent in all tissues in the treated group compared with the controls. CONCLUSION: These experiments support our hypothesis and provide evidence that lecithin may preserve cochlear mitochondrial function and protect hearing loss associated with aging."
[126a] Functions of poly(ADP-ribose) polymerase in controlling telomere length and chromosomal stability. d'Adda di Fagagna F, Hande MP, Tong WM, Lansdorp PM, Wang ZQ, Jackson SP in Nat Genet 1999 Sep;23(1):76-80
"In most eukaryotes, poly(ADP-ribose) polymerase (PARP) recognizes DNA strand interruptions generated in vivo. […]mice lacking PARP display telomere shortening compared with wild-type mice. Telomere shortening is seen in different genetic backgrounds and in different tissues, both from embryos and adult mice. In vitro telomerase activity, however, is not altered in Adprt1-/- mouse fibroblasts. Furthermore, cytogenetic analysis of mouse embryonic fibroblasts reveals that lack of PARP is associated with severe chromosomal instability, characterized by increased frequencies of chromosome fusions and aneuploidy."
[126b] Misregulation of gene expression in primary fibroblasts lacking poly(ADP-ribose) polymerase. Simbulan-Rosenthal CM, Ly DH, Rosenthal DS, Konopka G, Luo R, Wang ZQ, Schultz PG, Smulson ME in Proc Natl Acad Sci U S A 2000 Oct 10;97(21):11274-9
"Poly(ADP-ribose) polymerase (PARP) is implicated in the maintenance of genomic integrity, given that inhibition or depletion of this enzyme increases genomic instability in cells exposed to genotoxic agents. [….] The loss of PARP results in down-regulation of the expression of several genes involved in regulation of cell cycle progression or mitosis, DNA replication, or chromosomal processing or assembly. PARP deficiency also up-regulates genes that encode extracellular matrix or cytoskeletal proteins that are implicated in cancer initiation or progression or in normal or premature aging. These results provide insight into the mechanism by which PARP deficiency impairs mitotic function, thereby resulting in the genomic alterations and chromosomal abnormalities as well as in altered expression of genes that may contribute to genomic instability, cancer, and aging."
[126c] Chromosomal aberrations in PARP(-/-) mice: genome stabilization in immortalized cells by reintroduction of poly(ADP-ribose) polymerase cDNA. Simbulan-Rosenthal CM, Haddad BR, Rosenthal DS, Weaver Z, Coleman A, Luo R, Young HM, Wang ZQ, Ried T, Smulson ME in Proc Natl Acad Sci U S A 1999 Nov 9;96(23):13191-6
"Depletion of poly(ADP-ribose) polymerase (PARP) increases the frequency of recombination, gene amplification, sister chromatid exchanges, and micronuclei formation in cells exposed to genotoxic agents, implicating PARP in the maintenance of genomic stability. [….] These results further implicate PARP in the maintenance of genomic stability and suggest that altered expression of p53, Rb, and Jun, as well as undoubtedly many other proteins may be a result of genomic instability associated with PARP deficiency."
[127a] Vitamin B12 absorption test and oral treatment in 14 children with selective vitamin B12 malabsorption. Altay C, Cetin M in Pediatr Hematol Oncol 1999 Mar-Apr;16(2):159-63
"This study lends further support to the use of megadoses of VB12 as an alternative treatment for selective VB12 malabsorption."
[127b] Did we learn evidence-based medicine in medical school? Some common medical mythology. Paauw DS in J Am Board Fam Pract 1999 Mar-Apr;12(2):143-9
"Medical myths occur for many different reasons. A common thread is that they all make some pathophysiologic sense. A good example is the concern about using oral cobalamin when treating pernicious anemia. The difficulty in absorbing vitamin B12 when intrinsic factor is not available does not make oral replacement impossible; the dose just needs to be higher."