Abstract
Background: :
Dietary carbohydrates comprise a large proportion of our energy source. In vitro and animal studies indicate that carbohydrates damage lens proteins. Nevertheless, literature regarding relations between dietary carbohydrates and cataract development in non–diabetics is very limited (1).
Purpose: :
To test whether recent dietary carbohydrate intake or glycemic index (GI), a measure of carbohydrate intake quality, is associated with the presence of cortical or nuclear opacities.
Design: :
A modified Block food frequency questionnaire was used to obtain dietary information from participants in the Age–Related Eye Disease Study (AREDS). Lens status was evaluated using the AREDS System for Classifying Cataracts. Associations were examined for eyes (3377 persons; 5929 eyes) with only a single, or pure, type of lens opacity. The generalized estimating approach to logistic regression was used to account for the lack of independence between the eyes of an individual.
Results: :
For persons in the highest quartile of dietary GI, dietary GI was associated with more frequent occurrence of all grades of pure nuclear opacities (grade > 2) (odds ratio (OR) = 1.29, 95% CI, 1.04–1.59; Ptrend = 0.02) and moderate nuclear opacities (grade ≥ 4) (OR = 1.43, 95% CI, 0.96–2.14; Ptrend = 0.052). Carbohydrate nutrition was also associated with risk for cortical opacities. After adjusting for dietary GI and other potential confounders, there was a marginally statistically significant positive trend for cortical opacities of any severity (>0% area opaque), suggesting they are more common among participants with higher carbohydrate intake. The OR comparing the highest with the lowest quartile of intake was 1.27 (95% CI, 0.99–1.63; Ptrend = 0.09). The OR was somewhat higher for moderate cortical opacities (> 5% area opaque) (OR = 1.71, 95% CI, 1.00–2.95; Ptrend = 0.056). These associations were not modified by gender, education level, vitamin C intake, smoking status, or body mass index.
Conclusions: :
Carbohydrate nutrition may be associated with prevalent nuclear and cortical opacities. Dietary carbohydrate quantity and dietary glycemic quality may play different roles in the development of cortical and nuclear lens opacities. (1) Chiu et al., Long–term dietary carbohydrate intake, glycemic index and odds for early nuclear and cortical lens opacities. Am. J. Clin. Nut. (2005) 81,1411–6.
Keywords: cataract • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • clinical (human) or epidemiologic studies: risk factor assessment