Total Antioxidant Capacity of the Diet and Risk of Age-Related Cataract A Population-Based Prospective Cohort of Women

IMPORTANCE To our knowledge, no previous epidemiologic study has investigated the association between all antioxidants in the diet and age-related cataract. The total antioxidant capacity (TAC) concept aims to measure the capacity from all antioxidants in the diet by also taking synergistic effects into account. OBJECTIVE To investigate the association between the TAC of the diet and the incidence of age-related cataract in a population-based prospective cohort of middle-aged and elderly women. DESIGN, SETTING, AND PARTICIPANTS Questionnaire-based nutrition survey within the prospective Swedish Mammography Cohort study, which included 30 607 women (aged 49-83 years) who were observed for age-related cataract incidence for a mean of 7.7 years. EXPOSURE The TAC of the diet was estimated using a database of foods analyzed with the oxygen radical absorbance capacity assay. MAIN OUTCOMES AND MEASURES Information on incident age-related cataract diagnosis and extraction was collected through linkage to registers in the study area. RESULTS There were 4309 incident cases of age-related cataracts during the mean 7.7 years of follow-up (234 371 person-years). The multivariable rate ratio in the highest quintile of the TAC of the diet compared with the lowest was 0.87 (95% CI, 0.79-0.96; P for trend = .03). The main contributors to dietary TAC in the study population were fruit and vegetables (44.3%), whole grains (17.0%), and coffee (15.1%). CONCLUSIONS AND RELEVANCE Dietary TAC was inversely associated with the risk of age-related cataract. Future studies examining all antioxidants in the diet in relation to age-related cataract are needed to confirm or refute our findings.