Vitamin C Supplementation Linked to Prevention and Treatment Of Cataracts

James Meschino DC, MS, ROHP

Researchers from Tufts University recently reported the results of their most recent study in the American Journal of Clinical Nutrition. They followed 492 non-diabetic participants from 1980 to 1995, extracting pertinent dietary, lifestyle and supplementation practices as well as performing a cataract screening assessment on each subject. Thirty-four percent of the group was found to have cataracts (cortical opacities). A review of the data indicated a significant link between age and Vitamin C intake for a very common form of cataracts, known as cortical cataracts.
For women younger than 60, a Vitamin C intake greater than 362 mg/day reduced risk of cataracts by 57% compared with those who had an intake of less than 140 mg/day. Those who took Vitamin C supplements for more that 10 years had a 60% reduction in risk compared to non-supplement users. Researchers also found that women who never smoked and had high intakes of folate and carotenoids showed a reduction in cataracts.
Dr Ronald Plotnik, an associate professor of ophthalmology at the University of Rochester, N.Y. was quoted as stating, “I think it makes sense that Vitamin C and other antioxidants might have a protective effect in terms of cataracts.” As he explains, previous research suggests that free radicals (from UV light and cigarettes) could contribute to the development of cataracts.
In the same month (February/02) the journal Ophthalmic Epidemiology, published the findings of the Roche European American Cataract Trial (REACT). This study was a randomized clinical trial to investigate the efficacy of an oral antioxidant, micronutrient mixture to slow progression of age-related cataracts. After 3 years, the subjects taking the Vitamin mixture, consisting of 18 mg Beta-carotene, 750 mg Vitamin C and 600 IU of Vitamin E, demonstrated a small, but significant deceleration in the progression of age-related cataracts. There were no reported adverse side effects in the treatment group. Together, these results imply that antioxidant vitamin supplementation, at moderate doses, is a safe and effective means to potentially prevent cataract development and should be considered therapeutically to help slow the progression of existing age-related cortical opacities.

References:

1) United Press International, Boston, Feb. 22, 2002
2) Chylack LT et al, The Roche European American Cataract Trial (REACT). Ophthalmic Epidemiol. 2002, 9; 1: 49-80.