Abstract
Purpose: :
To examine the relationship between dietary lipid intake and cataract prevalence, type, and severity.
Methods: :
The 4477 people in this analysis were 60 to 80 years of age at enrollment, had at least 1 natural lens, and best–corrected visual acuity of 20/32 or better in at least one eye. The AREDS System for Classifying Cataracts was used to assess cataract type and severity from slit lamp and retro–illumination photographs. The cataract classification scheme used in this report is described in AREDS Report 5 (Ophthalmol. 2001;108:1400–8). Nutrient intake was estimated from responses to a validated food frequency questionnaire administered at enrollment; the lowest quintile of intake represented the referent group for other quintiles. Nutrient intake estimates were energy–adjusted using the nutrient density model. Standardized questionnaires yielded demographic, lifestyle, medical, and ocular data. We used repeated measures logistic regression to evaluate the relationship of major dietary lipids (eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), monounsaturated fat, saturated fat, total cholesterol, arachidonic acid, linoleic acid, and α–linolenic acid) with cortical and nuclear cataract. People with moderate and mild cataract were compared to those with no cataract. There were 615 and 2044 persons with moderate and mild nuclear cataract, respectively; 1818 had none. There were 1068 and 2601 persons with moderate and mild cortical cataract, respectively; 808 had none.
Results: :
The likelihood of having moderate cortical cataract was lower among participants reporting highest consumption of EPA (OR = 0.7, 95% CI = 0.5–0.9) after statistically controlling for non–nutrient covariates. The likelihood of having moderate nuclear cataract was significantly reduced among subjects reporting highest intake of DHA (OR = 0.6, 95% CI = 0.5–0.9) and EPA (OR = 0.7, 95% CI = 0.5–1.0). In no other instances were lipid–cataract relationships observed between highest and lowest intake quintiles. Trend tests for other relationships did not attain statistical significance.
Conclusions: :
Higher EPA intake was associated with a 30% decrease in the likelihood of having moderate cortical or nuclear opacity. Higher DHA intake was associated with a similar reduction in the likelihood of having moderate nuclear cataract. Weaknesses of this retrospective observational study include the potential exposure misclassification and uncontrolled confounding.
Keywords: cataract • lipids • nutritional factors