Diet and cataract: the Blue Mountains Eye Study.

PURPOSE To investigate relationships between a wide range of macro- and micronutrients, including antioxidant vitamins, and the three main types of cataract in older people. DESIGN Population-based cross-sectional study. PARTICIPANTS Two thousand nine hundred people aged 49 to 97 years living in an urban community near Sydney, Australia. TESTING Food frequency questionnaires and lens photography. MAIN OUTCOME MEASURE Lens photographs were graded for presence and severity of cortical, nuclear, and posterior subcapsular cataracts. RESULTS Higher intakes of protein, vitamin A, niacin, thiamin, and riboflavin were associated with reduced prevalence of nuclear cataract. After adjusting for multiple known cataract risk factors, the odds ratios for those in the highest intake quintile groups compared to those in the lowest intake quintiles were 0.5 (95% confidence interval [CI], 0.3-0.8) for protein, 0.5 (95% CI, 0.3-0.9) for vitamin A, 0.6 (95% CI, 0.4-0.9) for niacin, 0.6 (95% CI, 0.4-0.9) for thiamin, and 0.5 (95% CI, 0.3-0.9) for riboflavin. Intake of polyunsaturated fats was associated with reduced prevalence of cortical cataract. No nutrients were associated with posterior subcapsular cataract. CONCLUSIONS The nucleus of the lens is particularly sensitive to nutrient deficiencies. Protein, vitamin A, niacin, thiamin, and riboflavin protected against nuclear cataract in this study.