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 > or =4; OR: 1.43; 95% CI: 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.