The 492 nondiabetic subjects were chosen from the Nurses Health Study cohort, a group of women nurses in the Boston area whose diet and health information has been followed up biennially since 1976. The participants received detailed eye examinations for the detection of several different forms of cataracts, and information on their long-term vitamin intake and supplement use was collected from food frequency questionnaires from 1980 through 1993 to 1995. Of all eyes examined, 34% had cortical opacities, a common form of cataracts involving intermediate fiber cells of the cortex. Thirty-nine percent of the eyes had other forms of cataracts, with one-third having lens clouding in more than one location. Most of the women had very early opacities and so had not experienced visual symptoms.
A significant interaction was observed between age, vitamin C intake, and the prevalence of cataracts. For women younger than 60 years, the consumption of vitamin C 362 mg/day was associated with a 57% lower risk of developing cortical opacities, and the use of vitamin C supplements for at least 10 years was associated with a 60% reduction in the risk of cataracts, when compared to no supplement use. Additionally, the incidence of posterior subcapsulary cataracts was considerably lower in women who had never smoked and who had high intakes of folate and carotenoids. These results add to a growing body of
Contact: Elizabeth Horowitz
American Journal of Clinical Nutrition