Vitamins E and C Disappoint in Cataract Prevention


T he longest placebo-controlled trial to date to test whether antioxidant vitamins reduce the risk of cataracts has failed to fnd such a beneft for the supplements. Because oxidative damage is a prominent feature of cataracts, one focus of nutrition research has been the link between dietary intake of nutrients with antioxidant potential, particularly vitamins E and C, and the risk of cataract, explained William G. Christen, ScD, of Brigham and Womens Hospital and Harvard Medical School, and col- leagues, writing in Archives of Ophthalmology.To investigate that possible link, Christen and colleagues analyzed data from the Phy- sicians Health Study II, which was primarily designed to look for benefts of supplements on cardiovascular disease. But the study of 14,641 older male doctors also followed-up on the development of cataracts among the participants. After an average of eight years, the men experienced a total of 1,174 cata- racts and 801 surgeries to remove cataracts.Participants had been randomly as- signed to receive vitamin E or placebo and vitamin C or placebo. Those in the vitamin E group received 400 international units (IU) of vitamin E daily or placebo. Those in vitamin C group received 500 milligrams of vitamin C on alternate days or placebo.The incidence of cataracts among the vitamin E versus placebo groups and the vitamin C versus placebo groups was almost identical. The researchers determined that there was no apparent beneft of vitamin E at any point during the trial. The results for vitamin C were even less encouraging: The effect of vitamin C on cataract and extrac- tion [removal] did not differ appreciably within categories of known or possible risk factors, other than a possible, but statisti- cally non-signifcant trend toward increased risk in those with a reported history of cardiovascular disease.Christen and colleagues concluded, In summary, these randomized trial data from a large population of middle-aged and older, generally well-nourished men indicate that long-term supplementation with high-dose vitamin E and vitamin C, either alone or in combination, has little effect on rates of cataract diagnosis and extraction.It could be, however, that supplementa- tion might still have an effect on subjects less well-nourished than the physicians in the study. Image analysis, rather than extraction, might also better quantify early grades of cataract. Archives of Ophthalmology, November 2010; abstract at< tent/full/128/11/1397>


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