Association of zinc and antioxidant nutrients with age-related maculopathy

Abstract

Objective: To quantify relationships between dietary intake of zinc and antioxidant nutrients and early and late age-related maculopathy (ARM).

Design: A retrospective longitudinal cohort design using data pertaining to diets in the past (1978-1980), which were assessed retrospectively using a food frequency questionnaire.

Setting: Beaver Dam, Wis.

Patients: A 50% random sample of free-living Beaver Dam Eye Study participants, 43 to 86 years of age (N = 1968).

Main outcome measure: The presence of early and late ARM determined from fundus photography.

Results: People in the highest vs lowest quintiles for intake of zinc from foods had lower risk for early ARM (odds ratio = 0.6, 95% confidence interval, 0.4-1.0, P for trend < .05). This relationship appeared to be stronger for some types of early ARM (increased retinal pigment) than for others. Zinc intake was unrelated to late ARM. However, small numbers (n = 30) of people with this condition limit the ability to draw conclusions about this later stage. Levels of carotenoids were unrelated to early or late ARM. Odds for early ARM were lower in people in the highest vs lowest quintiles for the intake of vitamins C or E. However, these associations were not statistically significant.

Conclusions: The data are weakly supportive of a protective effect of zinc on the development of some forms of early ARM. Prospective studies are needed to further evaluate the potential influence of these and other nutritional factors on different types and stages of age-related macular degeneration.