Dietary carbohydrate intake and glycemic index in relation to cortical and nuclear lens opacities in the Age-Related Eye Disease Study

Background: Little is known about the association between dietary carbohydrates and cataract in nondiabetic persons. Objective: The aim was to test whether recent dietary carbohydrate intakes or glycemic index (GI; a measure of carbohydrate intake quality) was associated with the presence of cortical or nuclear opacities. Design: A modified Block food-frequency questionnaire was used to obtain dietary information from 3377 participants (aged 60 - 80 y; 56% were women) in the Age-Related Eye Disease Study (AREDS). Lens status was evaluated by using the AREDS System for Classifying Cataracts. Associations were examined for eyes with only a single, or pure, type of lens opacity by using the generalized estimating approach to logistic regression to account for the lack of independence between the eyes of a person. Results: For participants in the highest quartile, dietary GI was associated with a higher prevalence of all pure nuclear opacities [grade > 2; odds ratio (OR): 1.29; 95% CI: 1.04, 1.59; P for trend = 0.02] and moderate nuclear opacities (grade greater than or equal to 4; OR: 1.43; 95% Cl: 0.96, 2.14; P for trend = 0.052). The OR in a comparison of the highest with the lowest quartile of intake was 1.27 (95% CI: 0.99, 1.63; P for trend = 0.09) for cortical opacities of any severity (> 0% of area opaque), and the OR increased somewhat for moderate cortical opacities (> 5% of area opaque; OR: 1.71; 95% CI: 1.00, 2.95; P for trend = 0.056). Conclusions: Results from the cross-sectional analysis of AREDS baseline data suggest that dietary glycemic quality and dietary carbohydrate quantity may be associated with prevalent nuclear and cortical opacities, respectively.