BETHESDA--Researchers have shown that taking vitamin C supplements for more than 10 years lowers risk of lens opacities that can lead to cataract surgery in older women.
The study appears in the October issue of the American Journal of Clinical Nutrition, the peer-reviewed publication of the American Society for Clinical Nutrition.
Paul F. Jacques, Sc.D., Scientist and Epidemiologist at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, along with 7 colleagues from Tufts and Harvard University, showed that use of vitamin C supplements for more than 10 years was associated with a 77% lower prevalence of early lens opacities and a 83% lower prevalence of moderate lens opacities in a group of women whose average age was slightly over 62-1/2.
As a person ages, cataracts in the eye result from an increasing loss of lens transparency. Opacity, or the condition of becoming opaque, comes from changes in the delicate protein fibers within the eye lens which gradually do not allow clear visual light rays to pass through to the retina. Opacification tends to progress with age. After 65, almost everyone has some degree of cataract formation, but interference with vision is often minor since many opacities are either small or on the edges of the lens.
The study participants were 247 Boston-area women aged 56 to 71 years who were selected from the Nurses Health Study (NHS).
The NHS began in 1976 when 121,700 female nurses, ages 30 to 55 and residing in 11 states, completed a mailed questionnaire on known and suspected risk factors for cancer and heart disease. Every 2 years since 1976, the women have been contacted to provide updated information.
Eligible members of the NHS were ranked according to high or low vitamin C intake, using total consumption (dietary plus supplements) from five prior NHS reports.
"Between 1990 and 1992, we invited about 300 eligible women with the highest
Contact: Paul F. Jacques, ScD
American Society for Clinical Nutrition/American Society for Nutritional Sciences