Jan 14, 2008
Women who have higher dietary intake of lutein and zeaxanthin—compounds found in yellow or dark, leafy vegetables—as well as more vitamin E from food and supplements appear to have a lower risk for developing cataracts, according to a report in the January issue of Archives of Ophthalmology, one of the JAMA/Archives journals.
"The oxidative hypothesis of cataract formation posits that reactive oxygen species can damage lens proteins and fiber cell membranes and that nutrients with antioxidant capabilities can protect against these changes," the authors write as background information in the article. Vitamin E, vitamin C, beta carotene, lutein and zeaxanthin are all believed to have antioxidant properties. Lutein and zeaxanthin are the only carotenoids—yellow plant pigments—present in the lens of the human eye and may also protect against cataracts by filtering harmful blue light.
William G. Christen, Sc.D., of Brigham & Women's Hospital and Harvard Medical School, Boston, and colleagues analyzed dietary information from 35,551 female health professionals who enrolled in the Women's Health Study in 1993. The women were then followed for an average of 10 years, and the diets of those who developed cataracts were compared with the diets of those who did not.
A total of 2,031 women developed cataracts during the study. When the participants were split into five groups based on the amount of lutein and zeaxanthin they consumed, those in the group who consumed the most (about 6,716 micrograms per day) had an 18 percent lower chance of developing cataracts than those who consumed the least (1,177 micrograms per day). The one-fifth who consumed the most vitamin E from food and supplements—about 262.4 milligrams per day—were 14 percent less likely than the one-fifth who got the least (4.4 milligrams per day).
"In conclusion, these prospective data from a large cohort of female health professionals indicate that higher intakes of lutein/zeaxanthin and vitamin E are associated with decreased risk of cataract," the authors write. "Although reliable data from randomized trials are accumulating for vitamin E and other antioxidant vitamins, randomized trial data for lutein/zeaxanthin are lacking. Such information will help to clarify the benefits of supplemental use of lutein/zeaxanthin and provide the most reliable evidence on which to base public health recommendations for cataract prevention by vitamin supplementation."