Intake of zinc and antioxidant micronutrients and early age-related maculopathy lesions

Abstract

Background: Macular degeneration, the end stage of age-related maculopathy (ARM), is the leading cause of legal blindness worldwide, and few modifiable risk factors are known. The high concentration of carotenoids in the macula, plus evidence linking oxidative stress to ARM and carotenoids to antioxidation, generated the hypothesis that higher antioxidant intakes can prevent ARM. Results of observational and intervention studies have been inconsistent.

Objective: To evaluate associations between intakes of zinc and antioxidant micronutrients and early ARM.

Methods: Between 1993 and 1995, ARM was assessed in 398 Boston-area women aged 53-74 y using the Wisconsin Age-related Maculopathy System of grading retinal fundus photographs. The women were a subset of the Nurses' Health Study cohort. Micronutrient intake was assessed by semi-quantitative food frequency questionnaires administered four times between 1980 and the baseline eye examinations.

Results: After multivariate adjustment for potential confounders, 1980 energy-adjusted intakes of alpha-carotene, beta-carotene, lycopene, total retinol, total vitamin A, and total vitamin E were significantly inversely related to the prevalence of pigmentary abnormalities (PA). Furthermore, increasing frequency of consuming foods high in alpha-or beta-carotene was associated with lower odds of PA; compared to women consuming these foods < 5 times/wk, odds ratios (95% CI) were 0.7 (0.3-1.6) for 5-6 times/wk, 0.6 (0.2-1.3) for 7-9.5 times/wk, and 0.3 (0.1-0.7)for > or =10 times/wk. Lutein/zeaxanthin intakes and more recent intakes of most carotenoids were unrelated to PA, and intakes of zinc and antioxidant micronutrients were unrelated to having large or intermediate drusen alone.