Posted on May 03, 2006, 2 p.m.
By Bill Freeman
Can humans really do anything to prolong life? A recent article by Christopher Wanjek in the Washington Post said "Humans can reap no such benefits from the continuing flood of anti-aging potions and precepts, which are at best naively optimistic and at worst fraudulent and harmful. Wanjeck goes on to say that "every book, powder or pill that promises a fountain of youth..... is just plain wrong."
"There is no intervention that has been proven to slow, stop or reverse aging. Period," says Leonard Hayflick, professor of anatomy at the University of California, San Francisco, a leader in the study of aging. Even New Age physician Deepak Chopra chimed in by saying legitimate anti-aging remedies can only keep a person from dying young, but they don't increase the life span.1
Human growth hormone, widely extolled on radio infomercials across America for its anti-aging properties, may produce side effects including the elevation of growth hormones that trigger the growth of tumors. Growth hormone is more appropriate for very old adults who have lost muscle mass and can't get up out of a chair any longer, not for middle-aged adults fighting the first signs of aging.2
So is there anything that adults can do to lengthen the human life span? Scientists want you to wait (as if everybody has the time) for gene therapy. The latest breakthrough is the so-called Methuselah gene, a portion of DNA that confers healthy old age to those who carry its active form.3 But don't wait around for genetics to prolong life. Gene therapy has yet to cure any disease, is likely to be too costly for the average person to afford and is more likely to be inserted in new genes in the offspring of the next generation.
Why wait for an antioxidant breakthrough?
Thomas Johnson at the University of Colorado-Boulder, is looking in another direction. Johnson found that by tweaking a certain gene in roundworms he could create a super antioxidant gene that would double the worm's life span.4
But while researchers conduct their antioxidant studies on roundworms, what can we do? Actually youth seekers need look no further than the vitamin shelf at local stores for a well substantiated. anti-aging compound – vitamin C. While researchers attempt to make careers out of their research and thus delay any conclusions indefinitely, vitamin C may be the anti-aging miracle humanity can begin to use today. The story is not new, it's just not been widely told.
Humans have the capacity to live for hundreds of years
The good news is that there is scientific evidence that humans have the capacity to lengthen their average life span by hundreds of years. The evidence for vitamin C as a key anti-aging agent is compelling and rooted in the genetic makeup of humans. All humans are mutants. Homo sapiens, guinea pigs, monkeys, bats, some fish and many birds, do not produce their own vitamin C. The rest of the animal kingdom synthesizes their own vitamin C. For them, ascorbic acid is a hormone, not a dietary-acquired vitamin. Animals employ different organs to produce vitamin C. Some birds and reptiles use their kidneys and perching birds and mammals make vitamin C in their liver.5
Humans once made vitamin C in their liver by the production of four enzymes which convert circulating sugars into ascorbic acid (vitamin C). Humans today only make 3 of the 4 enzymes required to convert glucose (sugar) into ascorbic acid. A progressive mutation at some time in past generations deactivated the gene for the enzyme gulonolactone oxidase and slowly as the mutation progressed the synthesis of vitamin C came to an end in humans.
Mammals who make their own vitamin C can live 8-10 times beyond their age of physical maturity. Mammals without this ability have a difficult time reaching 3-4 times. Researchers believe the reinstallation of the gulonolactone oxidase enzyme in humans would extend the lifespan to hundreds of years.
This means that humans at one time in the past, prior to this gene mutation, lived for hundreds of years. This doesn't fit with the current evolutionary scheme of biology which postulates that humans evolved from monkeys and early man lived no longer than 40 years.
Darwinian theory off the mark
In 1966 Irwin Stone, a chemical engineer, theorized that the mutation of the gulonolactone oxidase enzyme in humans had been part of human evolution. There had been a branching of the Prosimii and the Anthropoidea orders of monkeys. The Anthropoidea developed the inactive gene for vitamin C and that branch evolved into humans.6
Health writer Jack Challem in 1997 also hypothesized that either a virus or free radical attack caused the genetic defect that disabled the enzyme necessary for vitamin C synthesis and that this in turn led to mutations that propelled the evolution of monkeys to humans.7
Of course, mutations are destructive and regressive, not progressive advancements of the genome. According to Darwin's theory of natural selection (survival of the fittest), humans or monkeys who could not produce their own vitamin C would have been less likely to thrive. Of course these theories are based upon suppositions which depict branch-like evolution from simple life forms to monkeys and finally humans. With no intermediate species (no missing links), these evolutionary tree charts are still nothing more than cartoons.
According to paleontologists early humans lived for about 40 years and only in recent times has the human life span dramatically shifted upwards. But then again, we have that evidence that humans at one time in the past made their own vitamin C. What evidence do we have, if any, that humans at some time in the past lived for hundreds of years?
When did humans live for hundreds of years?
An examination of the historical records of the Holy Bible reveals that Adam was recorded to have lived for 930 years (Genesis 5:5), and Noah for 950 years (Genesis 9:29). According to the Biblical record the human genome was severely narrowed at that time, down to just eight members of Noah's family as gene carriers. Thereafter the human life span was recorded to slowly dissipate. After the Flood, Bible genealogies indicate Shem lived 600 years, followed by Arphaxad who lived 438 years, and through other generations on down to Abraham who lived 175 years and finally to Moses who lived 120 years (Deuteronomy 34:7). This description would fit the progressive mutation of the gulonolactone oxidase gene. Humans still house this gene, it is just defunct and called a pseudogene. Thus the Biblical genealogies may not be far-fetched fairy tales.
Can the enzyme to produce vitamin C be re-installed in humans?
What if the gulonolactone oxidase gene could somehow be re-inserted into the human genome?
We know that guinea pigs who lack gulonolactone oxidase have been given this enzyme by injection and are able to survive on a diet deficient in vitamin C.8
Scientists have taken the gulonolactone oxidase DNA from rat liver and successfully tranplanted it into the tomato genome.9 The gulonolactone oxidase gene has also been successfully transferred into a teleost fish (Oryzias latipes) via microinjection into fertilized fish eggs.10
With all of the widely heralded prospects for gene therapy there hasn't been a peep about the feasability of inserting the gulonolactone oxidase gene into the human genome. Yet the profound impact of such a development, if successful, would obviously be monumental. Diabetes, blood vessel disease, cataracts, gallstones, to name a few age-related maladies, would be eradicated. The breakdown of collagen with advancing age would be slowed. The world human population jumped from 1.6 to 6..1 billion in the past century, 2 billion of that growth coming since 1960, largely from improvements in sanitation, food fortification and modern medicines.11 Imagine the social, political and medical ramifications if humans could live for hundreds of years?
Does vitamin C supplementation work?
As early as 1984 researchers knew that supplementation of drinking water with vitamin C increased the average life span of mice by as much as 20 percent.12
Nobel prize winner Dr. Linus Pauling suggested humans supplement their diet continually through the day to mimic what the liver would make if the gene for the gulonolactone oxidase enzyme were still active. Dr. Pauling advocated supplementation with mineral ascorbates, the same alkaline form of vitamin C the liver produces in mammals, not ascorbic acid which can sometimes be irritating to the stomach and can even eat away tooth enamel.13
How much vitamin C should humans ingest? If you want to get all your vitamin C from foods, consumption of the recommended 5 to 7 servings of fruits and vegetables a day is likely to provide 200-250 milligrams. A mouse makes about 275 milligrams of vitamin C per day per kilogram (2.2 lbs) of body weight. If a mouse weighed 154 pounds, about the weight of a human, this would amount to about 19,250 milligrams of vitamin C per day. A 160-pound goat produces about 13,000 milligrams per day, and more under stress. A dog or cat will produce about 40 milligrams of vitamin C per kilogram of body weight per day, or the equivalent of 2800 mgs per day if these animals were about the same size as humans. So using animals as a rule of thumb, humans may benefit from consumption of anywhere from 2,000-20,000 milligrams per day. The only common side effect from high-dose vitamin C is a transient diarrhea-like buildup of water in the lower bowel. Government health authorities recommend only about 90 milligrams of vitamin C a day for adults, but that's just the minimum amount to prevent scurvy and promote general health, not to achieve optimal health and longevity. Studies indicate the vitamin C intake for Americans is around 110 milligrams per day, but adequate vitamin C status, even with food fortification, is still not guaranteed. According to one study, about 1-2 percent of college students exhibited true deficiency and marginal deficiencies were found in an additional 12-16 percent of students.14
Can vitamin C prolong life?
Is there any evidence that increased vitamin C consumption can prolong the human life span? A study of 11,000 Americans over 10 years revealed that individuals with the highest level of vitamin C intake, only about 300 milligrams, suffered 35 percent fewer deaths than those with the lowest intake, about 50 milligrams a day. This amounts to about 6 added years of life to those who consume higher levels of vitamin C. Since 300 mg of vitamin C is difficult to obtain from dietary sources alone, the primary group that exhibited increased life span were the vitamin C supplement users.15 A person would have to consume five oranges a day to get 300 milligrams of vitamin C from their diet alone.
There are other corroborating studies that back up the idea of vitamin C supplementation and longevity.
A study over a 12-16-year period showed that males with the highest blood serum levels of vitamin C experienced a 57 percent drop in their risk of dying from any cause compared to males with low circulating levels of vitamin C.16
Among men and women ages 45-79 years, just a 50 milligram increase in vitamin C consumption was able to reduce the relative all-cause mortality rate by 20 percent.17
Another study published in 2001 also confirms a 25-29 percent decreased all-cause mortality rate among adults with normal to high circulating levels of vitamin C.18
It is interesting to note that vitamin C acts as an agent in various models of anti-aging. Vitamin C would be a key antioxidant in the free radical theory of aging.19 Researchers have demonstrated that vitamin C slows down telomere shortening by 52-62 percent in a controlled experiment.20 Telomeres are the end caps of DNA that shorten with many generations and limit the number of replications of DNA.
Is high-dose vitamin C genotoxic?
However, with all of this positive information about vitamin C, the news media recently chose to widely circulate a misleading test-tube study claiming high-dose vitamin C is toxic to DNA which could cause cancer. Researchers recommended vitamin C supplements be restricted to no more than 200 milligrams per day. This report caused the public to temporarily pause regarding vitamin C supplements.21 However, the 200-milligram limit conflicts with government health authorities who recommend consumption of 5-7 servings of fruits and vegetables per day which would likely provide more than the 200 milligram amount. Virtually all evidence from dietary studies confirm the health benefits of foods that provide high amounts of vitamin C. Another earlier study published in Nature indicated 500 milligrams of vitamin C in humans may produce damage to DNA in lymphocytes, a type of white blood cell.22 However, other studies reveal that vitamin C actually protects against DNA damage to lymphocytes but this protective effect is greatly enhanced when accompanied by bioflavonoids which usually accompany vitamin C in nature.23 Bioflavonoids are plant pigments commonly found in citrus, berries, grapes and tea leaves. The better store brands of buffered vitamin C powder (mineral ascorbates) include bioflavonoids. Furthermore, five other subsequent human studies were conducted using high-dose vitamin C up to 5000 milligrams per day and could not find evidence that vitamin C induces gene mutations.24
Then there is the aforementioned evidence from the animal kingdom where animals produce thousands of milligrams of vitamin C daily without evidence this induces cancer. A modern mountain gorilla living in its natural habitat, that produces no vitamin C on its own, would obtain 4,500 milligrams of vitamin C per day from native foodstuffs.25 A 15 pound howler monkey takes in 600 milligrams of vitamin C per day and an 18 pound spider monkey consumes about 744 mg of vitamin C per day.26 There is no evidence that these levels of vitamin C from dietary sources induce any DNA mutations or cancer in these animals.
Furthermore, there are studies which reveal significant health benefits for humans who consume vitamin C in excess of the newly established 90 milligram reference daily intake. For example, human studies reveal that 300 milligrams of daily vitamin C appears to reduce the risk of blinding cataracts, an otherwise inevitable consequence of aging, by 77-83 percent.27 A 500-milligram daily dose of vitamin C has been found to significantly reduce blood pressure among hypertensive patients who previously had to use prescription medications.28
Anyone interested in anti-aging should begin with vitamin C, the missing human hormone.
Part II: What we can learn about anti-aging from mynah birds, fruit flies and leeches
1. Wanjek C, Time in a bottle, Washington Post, Jan 29, 2002
2. Riedl M, et al, Growth hormone in the elderly man, Wien Med Wochenschr 151: 426-29, 2001.
3. McKie R, Discovery of Methuselah gene unlocks secret of long life, The Observer, Feb. 3, 2002.
4. Fischer JS, The cells of immortality, US New Online, March 20, 2000.
5. McCluskey ES, Which vertebrates make vitamin C?, Origins 12: 96-100, 1985.
6. Stone I, The natural history of ascorbic acid in the evolution of the mammals and primates and its significance for present day man, Orthomolecular Psychiatry 1: 82-89, 1972; Stone I, Homo sapiens ascorbicus, a biochemically corrected robust human mutant, Medical Hypotheses 5: 711-21, 1979..
7. Challem JJ, Did the loss of endogenous ascorbate propel the evolution of Anthropoidea and Homo sapiens? Medical Hypotheses 48: 387-92, 1997.
8. Sato PH, et al, Treatment of a metabolic disease, scurvy, by administration of a missing enzyme, Biochem Med Metab Biol 35: 59-64, 1986; Hadley K, Sato P, A protocol for the successful long-term enzyme replacement therapy of scurvy in guinea pigs, J Inherit Metabolic Diseases 11: 387-96, 1988.
9. Tsuyoshi I, et al, The American Society of Plant Physiologists, Plant Biology '97, Abstract 1545.
10. Toyohara H, et al, Transgenic expression of L-gulono-gamme-lactone oxidase in medaka (Oryzias latipes), a teleost fish that lacks this enzyme necessary for L-ascorbic acid biosynthesis, Biochem Biophys Res Commun 223: 650-53, 1996.
11. Human population: fundamentals of growth, Population Reference Bureau, 2002.
12. Massie HR, et al, Dietary vitamin C improves the survival of mice, Gerontology 30: 371-75, 1984
13. Pauling L, How to Live Longer and Feel Better, July 1996.
14. Johnston CS, et al, Vitamin C status of a compus population: college students get a C minus, J Am College Health 46: 209-13, 1998.
15. Cowley G, Church V, Live longer with vitamin C, Newsweek May 18, 1992 and Enstrom JE, et al, Vitamin C intake and mortality among a sample of the United States population, Epidemiology 3: 194-202, 1992.
16. Loria CM, et al, Vitamin C status and mortality in US adults, American Journal Clinical Nutrition 72: 139-45, 2000.
17. Khaw, K, et al, Relation between plasma ascorbic acid and mortality in men and women in EPIC-Norfolk prospective study: a prospective population study, The Lancet 357: March 3, 2001.
18. Simon JA, et al, Relation of serum ascorbic acid to mortality among US adults, J Am College Nutrition 20: June 2001.
19. Harman D, Piette LH, Free radical theory of aging: free radical reactions in serium, J Gerontology 21: 560-65, 1966.
20. Furumoto K, et al, Age-dependent telomere shortening is slowed down by enrichment of intracellular vitamin C via suppression of oxidative stress, Life Sciences 63: 935-48, 1998.
21. Lee SH, et al, Vitamin C-induced decomposition of lipid hydroperoxides to endogenous genotoxins, Science 292: 2083-86, 2001.
22. Podmore ID, et al, Vitamin C exhibits pro-oxidant properties, Nature 392: 559, 1998.
23. Noroozi M, et al, Effects of flavonoids and vitamin C on oxidative DNA damage to human lymphocytes, Am J Clin Nutrition 67: 1210-18, 1998.
24. Sardi B, The two faces of vitamin C, Science 293: 5537, 2001.
25. Bourne C, Vitamin C and immunity, British J Nutrition 2: 341, 1949.
26. Milton K, Eating what comes naturally: an examination of some differences between the dietary components of humans and wild primates, Dept. Antropology, University of Calif. Berkeley, 14th Intl' Congress on Anthropological and ethnological Sciences, July 26, 1998.
27. Jacques PF, et al, Long-term vitamin C supplement use and prevalence of early age-related lens opacities, Am J Clinical Nutrition 66: 911-16, 1997.
28. Duffy SJ, et al, Treatment of hypertension with ascorbic acid, The Lancet 354: Dec. 11, 1995.
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