Antioxidants Misunderstood (New Scientist)

Antioxidants Misunderstood By Neil E. Levin, CCN, DANLACertified Clinical Nutritionist, Diplomate in Advanced Nutritional Laboratory Assessment In the August 5, 2006 issue of New Scientist the article, “The Antioxidant Myth” somehow failed to uncover some of the truths about antioxidants, raising questions about the depth of the reporting and the lack of understanding of the interactions between antioxidants that is so critical to their functioning. It is telling that much of the criticism of antioxidants comes from science that is testing single nutrients, using a drug model. But knowledgeable antioxidant researchers are aware that this is a “family” of nutrients that can synergistically “recharge” each other, making single nutrient studies fairly irrelevant as to the holistic interaction of these substances in vivo. For example, a study in Finland was halted early because of a widely reported increase in cancer rates among male smokers taking beta-carotene. (1) A more complete analysis published in July 2004 took another look at data from that same study, but now taking into account total antioxidant intake, which exonerated beta-carotene as a cause of the cancers/deaths. The smokers’ risk of getting lung cancer was strongly associated with low total antioxidants in the diet. (2) Another large study has noted that high carotenoid intake, confirmed by measures of blood levels, was associated with lower mortality rates among the elderly over a ten year period. (3) Still, news reports continue to refer to beta-carotene as harmful, and even the NIH has failed to consider the evolution of the data showing that low total antioxidant status is the key risk factor, one that even supplementation with beta carotene alone cannot be expected to correct. Vitamin E is another example. The New Scientist article says that “There is even some evidence that vitamin E supplements can be harmful”, right before quoting a scientist as saying that a re-analysis of the data showed “no change in mortality”, asserting that the “evidence” of the vitamin causing harm was “flawed”. This was due to the use of a poor statistical model (4) that was corrected in a later publication (5) and should not reflect on Vitamin E’s fine safety record (6). The article also questioned the use of Vitamin E and other antioxidants as dietary supplements, rather than from food, though published studies have shown that Vitamin E from dietary supplements is clinically effective. (7-8, 13-17) Levels of Vitamin E above 100 IU daily are associated with decreased risk of coronary heart disease and certain types of cancer, as well as enhancement of immune function. These vitamin E intakes are considerably above levels obtainable from diet alone. (9-11) Antioxidants are also shown to help against aging. Lutein supplements have been shown to be useful against age-related macular degeneration, a leading cause of blindness in the elderly, in the Veterans LAST study (Lutein Antioxidant Supplementation Trial). Vitamin E has been shown to reduce formation of cataracts. (12) The Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study demonstrated a 32% reduction in prostate cancer incidence in response to daily alpha-tocopherol (Vitamin E) supplementation. (13) ALS (amyotrophic lateral sclerosis) mortality was 62% lower among long-term users of vitamin E than among nonusers. (14) In a study of cancer patients done for the US Dept. of Health and Human Services, “Subgroup analysis did identify a statistically significant 9% reduction in all cause mortality” and “13% reduction in all-cancer mortality associated with supplemental vitamin E in combination with other micro-nutrients.” (15) In a study done by Tufts University, the USDA and the National Institute on Aging, published in JAMA, it was reported that with 200 IU per day of vitamin E given to elderly people, “we observed a protective effect of vitamin E supplementation on upper respiratory tract infections, particularly the common cold, that merits further investigation”. (16) In another clinical trial, Vitamin E (VE) “strongly affected the expression of an array of genes encoding for proteins directly or indirectly involved in the clearance of amyloid beta, changes which are consistent with a protective effect of VE on Alzheimer's disease progression”. (17) Much of the negativity about antioxidants in the article comes from a single scientist in Singapore and does not accurately express the state of the science on the topic. Other problems commonly arise from the use of meta-analyses, a statistical analysis of previously published studies that often multiplies confounding variables and can produce inaccurate results if done by people unfamiliar with the intricacies of nutrition and supplementation. Unfortunately, this article in New Science uses old science that has been virtually repudiated and has not included a fair representation of the whole body of science in which antioxidants do have documented benefits for problems associated with aging. REFERENCES: 1. N Engl J Med. 1994 Apr 14;330(15):1029-35. The effect of vitamin E and beta carotene on the incidence of lung cancer and other cancers in male smokers. The Alpha-Tocopherol, Beta Carotene Cancer Prevention Study Group. 2. July 2004 American Journal of Epidemiology Development of a Comprehensive Dietary Antioxidant Index and Application to Lung Cancer Risk in a Cohort of Male Smokers. Margaret E. Wright , Susan T. Mayne, Rachael Z. Stolzenberg-Solomon, Zhaohai Li, Pirjo Pietinen, Philip R. Taylor, Jarmo Virtamo and Demetrius Albanes 3. Am J Clin Nutr 2005;82:879–886. Plasma carotene and alpha-tocopherol in relation to 10-y all-cause and cause-specific mortality in European elderly: The Survey in Europe on Nutrition and the Elderly, a Concerted Action (SENECA). Buijsse B, Feskens EJ, Schlettwein-Gsell D, Ferry M, Kok FJ, Kromhout D, de Groot LC. 4. Edgar R. Miller, III, MD, PhD; et al. High-dose vitamin E supplementation may increase all-cause mortality, a dose response meta-analysis of randomized trials. Annals of Internal Medicine: Online: Nov. 10, 2004: Print: 4 January 2005 Volume 142 Issue 1 5. John N Hathcock, et al. REVIEW ARTICLE: Vitamins E and C are safe across a broad range of intakes. American Journal of Clinical Nutrition, Vol. 81, No. 4, 736-745, April 2005. 6. Food and Nutrition Board, Institute of Medicine. Dietary reference intakes for vitamin C, vitamin E, selenium, and carotenoids. A report of the Panel on Dietary Antioxidants and Related Compounds, Subcommittees on Upper Reference Levels of Nutrients and Interpretation and Uses of Dietary Reference Intakes, and the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. Washington, DC: National Academy Press, 2000. 7. Emmert DH, Kirchner JT. The role of vitamin E in the prevention of heart disease. Arch Fam Med. 1999 Nov-Dec;8(6):537-42. 8. Stampfer MJ, et al. Vitamin E consumption and the risk of coronary disease in women. N Engl J Med 1993;328:1444-9 9. Bauernfeind, J. Tocopherols in Foods. In: Vitamin E: A Comprehensive Treatise. Marcel Dekker, Inc., New York and Basel, pp. 99-167, 1980. 10. Horwitt, M.K. The Promotion of Vitamin E. J. Nutr. 116:1371-1377, 1986. 11. Weber, P., Bendich, A. and Machlin, L.J. Vitamin E and Human Health: Rationale for Determining Recommended Intake Levels. Nutrition 13:450-460, 1997. 12. Annals of Ophthalmology. Vol. 123 No. 4, April 2005 13. Journal of the National Cancer Institute, Vol. 97, No. 5, 396-399, March 2, 2005 14. Ann Neurol. 2004. Volume 57, Issue 1 , Pages 104 – 110 15. Evid Rep Technol Assess (Summ). 2003 Oct;(75):1-3. Review. PMID: 15523748 16. JAMA. Vol. 292 No. 7, August 18, 2004 17. Gene study suggests vitamin E helps blocks Alzheimer's. Nutr Neurosci. 2005 Feb;8(1):21-9. PMID: 15909764