A large body of experimental research indicates that oxidative stress contributes to the processes related to aging and to the pathogenesis of several age-related diseases. Vitamins and antioxidant enzymes have a fundamental role in defending the organism from oxidative stress.
...From these results, it is evident that healthy centenarians show a particular profile in which high levels of vitamin A and vitamin E seem to be important in guaranteeing their extreme longevity.
PMID: 10889454 [PubMed - indexed for MEDLINE]
- Antioxidants help protect the body from chronic degenerative diseases, such as heart disease and cancer, combat premature aging, and support a healthy immune system.
- An intake of antioxidants in excess of the Recommended Dietary Allowances (RDAs) is probably necessary for optimal health protection.
A combination of antioxidants may be more effective than single antioxidants.
- The role of free radicals (unruly molecules that damage the body) as instigators of disease is now an accepted fact in most scientific quarters. However, continuing research in the antioxidant field clarifies the role of antioxidants in disease and uncovers antioxidant links to new health conditions.
HEART PROTECTION
It was almost a year ago that vitamin E gained new respect for guarding against heart disease. The Cambridge Heart Antioxidant Study (CHAOS) assigned 2,002 men and women diagnosed with atherosclerosis to take vitamin E supplements (containing either 400 I.U. or 800 I.U.) or a placebo daily. After 17 months of using the supplements, the risk of non-fatal heart attack was reduced by 77%. The risk of fatal heart attacks was also significantly reduced. (Stephens, N.G., Lancet, 1996;347:781-786.)
Researchers from the University of Minnesota School of Public Health assessed the diets of 34,486 women and followed their health for 7 years. When intakes of vitamin E were compared to mortality, it was found that the risk of dying from heart disease decreased as dietary vitamin E intakes increased. The women in the highest vitamin E group had a 58% lower risk compared to women in the lowest group. (Kushi, L., et al., New England Journal of Medicine, 1996;334:1156-1162.)
Clearly, lifelong high levels of antioxidant nutrients protect against the development of heart disease, but it may never be too late for heart disease patients to benefit from antioxidants. High doses of antioxidants (vitamins A, C, and E, and beta-carotene) in the month following an acute heart attack can significantly reduce the number of deaths, as well as the extent of cardiac damage in non-fatal cases. (Singh, R.B., et al., American Journal of Cardiology, February 1, 1996;77:232-236.)
ROLE IN CANCER PREVENTION
Antioxidants' reputation has taken a beating in the press lately Some studies show no effect of antioxidants on cancer, and other studies -- such as a study of beta-carotene in smokers -- actually show a detrimental effect. Researchers at the Center for Vitamins and Cancer Research at the University of Colorado Health Sciences Center may have an explanation for the apparent inconsistencies of antioxidants and cancer risk.
It appears that combinations of antioxidant vitamins are the most effective in inhibiting tumor growth, and "in the absence of knowledge of doses and the effect of potential interaction, cancer prevention trials among high-risk populations or cancer treatment trials can be ineffective. Therefore the current clinical trials on cancer prevention in which one or two arbitrarily selected vitamins at arbitrarily selected doses are used are likely to yield inconsistent results." (Prasad, K.N., et al., Nutrition and Cancer, 1996;26:11-19.)
ANTIOXIDANTS AND LONGEVITY
A group of researchers from Italy recently compared the antioxidant blood levels, free radical activity, and state of health of 100 healthy and 62 disabled 80+ year old adults with 91 middle-aged adults. Those over 80 years old showed greater systemic oxidative stress and lower levels of antioxidants, such as vitamin C and vitamin E. Within the elderly group, those who were unhealthy (that is aging unsuccessfully compared to those who were aging successfully) showed the greatest systemic oxidant load. (Mezzetti, A., Journal of the American Geriatrics Society, 1996;44:823-827.)
When crucial strands of protein in the cells of the brain and immune system deteriorate with age, they send a signal to the body that the cell is old and should be destroyed. This protein, called band 3 protein, is a sign of immune system and neurological aging. Vitamin E has been found to prevent, or at least delay, this indication of aging and prolong the life of cells in the laboratory. (Kay, M.B., et al., Proceedings of the National Academy of Sciences, May 1996;93:5600-5603.)
ANTIOXIDANTS SLOW OSTEOARTHRITIS
High doses of antioxidant vitamins can slow the progression of osteoarthritis of the knee, says Timothy E. McAlindon, D.M., and colleagues in Arthritis & Rheumatism (1996;39(4):648-656). High intake of vitamin C may slow the progression of osteoarthritis by as much as three-fold; the benefits of betacarotene and vitamin E were not as strong.
VITAMIN E PRESERVES FERTILITY
Male smokers may have dangerously high levels of sperm damage, compared to non-smokers, which could "lead to cancer, birth defects, and genetic diseases in [their] offspring," says a study in Mutation Research (1996;351:199-203). One marker of sperm DNA damage was 50% higher and vitamin E levels were 32% lower in smokers. The antioxidant activity of vitamin E and other antioxidants could reduce smoking-related sperm damage.
UPPING VITAMIN C RECOMMENDATIONS
Dr. Mark Levine at the National Institutes of Health recommends that the RDA for vitamin C should triple to about 200 mg. daily. Dr. Levine's study examined vitamin C absorption and excretion in only seven men, but the conditions of the study were rigorously controlled.
Daily intakes of vitamin C at the highest level tested (2,500 mg.) caused no adverse effects. In contrast, even a marginal deficiency of vitamin C resulted in feelings of fatigue and irritability. (Levine, M., Proceedings of the National Academy of Sciences, 1996;93:3704-3709.) *caution - large doses of vitamin C can cause intestinal upset; increase dosage gradually.
NEW ANTIOXIDANTS DISCOVERED
Most antioxidants are limited in where they work in the body. That is, they either protect the watery areas, such as the bloodstream, or the fatty areas, such as cell membranes. A new antioxidant, alpha-lipoic acid, has the unique ability to fight free radicals in both water-soluble and fat-soluble areas.
Dr. Lester Packer, an expert on this antioxidant, believes that "the therapeutic potential of alpha-lipoic acid is just beginning to be explored, but this compound holds great promise." (Packer, L., et al., Free Radical Biology & Medicine, 1996;20(4):625-626.)
Several flavonoids are recognized for their antioxidant and anti-viral activity. For example, researchers at the University of Arizona investigated the potential of Pycnogenol (a pine bark extract source of flavonoids) to fight infections, in particular HIV infection. This study determined that Pycnogenol restored the production of interleukin (cells that help the immune system communicate) and also restored the activity of natural killer cells, which go on "seek and destroy missions" for virus-infected cells. This is especially beneficial because depressed natural killer cell activity often leads to a rapid progression from HIV to full-blown AIDS. (Watson R.R., et al., Life Sciences, 1996;58(5):87-96).
To Your Total Success
Fran
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