High doses of antioxidants in supplement form, including ß-carotene, vitamin C, vitamin E, and zinc, reduce progression of age-related macular degeneration (AMD). To assess whether dietary antioxidants can prevent primary AMD, researchers evaluated data from a population-based prospective cohort study among older residents of Rotterdam, the Netherlands. Overall, 4170 participants (mean age, 67) had reliable dietary assessments and physical examinations at baseline, and underwent at least one physical exam during a mean 8 years of follow-up.
Incident AMD was diagnosed in 560 subjects. In analyses adjusted for potential confounders, above-average zinc consumption was associated with a modest but significant reduction in AMD risk; the reduction associated with high vitamin E intake was of borderline significance. Subjects who consumed more than the median level of all four antioxidants, compared with those who consumed less than the median amount of at least one, had a significant 35% reduction in risk. Controlling for antioxidant supplement use did not alter the results substantially.
In this study, high dietary intake of zinc, ß-carotene, and vitamins C and E was associated with substantially reduced risk for age-related macular degeneration. These data demonstrate the value of consuming a diet rich in all beneficial antioxidants, rather than focusing on supplements of specific antioxidants.
Reference:
van Leeuwen R et al. Dietary intake of antioxidants and risk of age-related macular degeneration. JAMA 2005 Dec 28; 294:3101-7.