ADVERTISEMENT

Antioxidants

The scientifically respected free-radical theory of aging36 serves as a basis for the prominent role that antioxidants have in the antiaging movement. The claim that ingesting supplements containing antioxidants can influence aging is often used to sell antiaging formulations. The logic used by their proponents reflects a misunderstanding of how cells detect and repair the damage caused by free radicals and the important role that free radicals play in normal physiological processes (such as the immune response and cell communication).37,38,39 Nevertheless, there is little doubt that ingesting fruits and vegetables (which contain antioxidants) can reduce the risk of having various age-associated diseases, such as cancer,40 heart disease,41,42 macular degeneration and cataracts.43,44 At present there is relatively little evidence from human studies that supplements containing antioxidants lead to a reduction in either the risk of these conditions or the rate of aging, but there are a number of ongoing randomized trials that address the possible role of supplements in a range of age-related conditions,45,46,47,48,49 the results of which will be reported in the coming years. In the meantime, possible adverse effects of single-dose supplements, such as beta-carotene,50 caution against their indiscriminate use. As such, antioxidant supplements may have some health benefits for some people, but so far there is no scientific evidence to justify the claim that they have any effect on human aging.51,52


36Harman D. Aging: A theory based on free radical and radiation chemistry. J Gerontol. 1956;11:298-300.

37Robert L, Labat-Robert J. Aging of connective tissues: from genetic to epigenetic mechanisms. Biogerontology. 2000;1:123-131.

38F¿l¿p Jr T, Douziech N, Jacob MP, Hauck M, Wallach J, Robert L. Age-related alterations in the signal transduction pathways of the elastin-laminin receptor. Pathol Bio. 2001;49:339-348.

39Labat-Robert J. Cell-matrix interactions, alterations with aging and age associated diseases. A review. Pathol Bio. 2001;49:349-352.

40World Cancer Research Fund. American institute for cancer research. Food, nutrition and the prevention of cancer: A global perspective; 1997.

41Tavani A, La Vecchia C. Beta-carotene and risk of coronary heart disease. A review of observational and intervention studies. Biomed Pharmacother. 1999;53(9):409-416.

42Hu FB, Willett WCJ. Diet and coronary heart disease: findings from the Nurses¿ health study and health professionals¿ follow-up Study. Nutr Health Aging. 2001;5(3):132-138.

43Van Duyn MA, Pivonka EJ. Overview of the health benefits of fruit and vegetable consumption for the dietetics professional: selected literature. Am Diet Assoc. 2000;100(12):1511-1521.

44Christen WG. Antioxidant vitamins and age-related eye disease. Proc Assoc Am Physicians. 1999;111(1):16-21.

45MRC/BHF Heart Protection Study Collaborative Group. MRC/BHF heart protection Study of cholesterol-lowering therapy and of antioxidant vitamin supplementation in a wide range of patients at increased risk of coronary heart disease death: early safety and efficacy experience. Eur Heart J. 1999;20:725-741.

46Manson JE, Gaziano M, Spelsberg A, et al for the WACS Research Group: A secondary prevention trial of antioxidant vitamins and cardiovascular disease in women. Rationale, design, and methods. Ann Epidemiol. 1995;5:261-269.

47Egan DA, Garg R, Wilt TJ, et al for the ADMIT Investigators: Rationale and design of the arterial disease multiple intervention trial (ADMIT) Pilot Study. Am J Cardiol. 1999;83:569-575.

48The Age-Related eye disease research group: The age-related eye disease study (AREDS): Design implications. AREDS Report No. 1. Control Clin Trials 1999;20:573-600.

49Tikellis G, Robman LD, Harper CA, et al. The VECAT study: methodology and statistical power for measurement of age-related macular features. Ophthalmic epidemiology. 1999;6:181-194.

50Paolini M, Abdel-Rahman SZ, Cantelli-Forti G, Legator LS. Chemoprevention or Antichemo- prevention? A salutary warning from the Beta-Carotene experience. J Natl Cancer Inst. 2001;93(14):1110-1111.

51Morley AA, Trainor KJ. Lack of an effect of vitamin E on lifespan of mice. Biogerontology. 2001;2:109-112.

52de Grey ADN. Noncorrelation between maximum life span and antioxidant enzyme levels among homeotherms: implications for retarding human aging. J Anti-Aging Med. 2000;3:25-36.


Next: Telomeres

Back to The Truth about Human Aging

Share this Article:

Comments

You must sign in or register as a ScientificAmerican.com member to submit a comment.
Scientific American Holiday Sale

Give a Gift &
Get a Gift - Free!

Give a 1 year subscription as low as $14.99

Subscribe Now! >

X

Email this Article

X