PLASMA ANTIOXIDANTS AND RISK OF CORTICAL AND NUCLEAR CATARACT

We evaluated nutritional risk factors for cataract in 660 subjects enr olled in the Baltimore Longitudinal Study on Aging. As a part of a reg ular cycle of visits, nuclear and cortical lens photographs were taken over a 2-year period. Measurements of plasma antioxidants (beta-carot ene, ascorbic acid, and alpha-tocopherol) were obtained in this cohort as part of the study protocol up to 4 years before lens photographs w ere taken. We found that plasma beta-carotene and ascorbic acid levels were not associated with risk of nuclear or cortical lens opacities. Higher levels of plasma alpha-tocopherol, however, were associated wit h a reduced risk of nuclear opacity [odds ratio (OR) for highest quart ile vs lowest quartile = 0.52, 95% confidence interval (CI) = 0.27-0.9 8; OR for middle two quartiles vs lowest quartile = 0.55, 95% CI = 0.3 0-0.98], after adjusting for age, sex, and history of diabetes. Middle levels of alpha-tocopherol were associated with a reduced risk of cor tical opacity (OR = 0.57, 95% CI = 0.32-1.02), but no such association was observed for high levels of alpha-tocopherol. We constructed an i ndex of overall antioxidant status, which indicated that higher levels of plasma antioxidants were not associated with risk of nuclear or co rtical opacities.