Supplements fail to halt cataracts, study finds

New findings from a large, national study that included San Antonio men found that two popular diet supplements, vitamin E and selenium, had little or no benefit in lowering the risk of developing cataracts.

A few smaller studies had suggested supplements, especially vitamin E, might prevent cataract development. But the latest findings, published in the journal JAMA Ophthalmology, cast doubt on any benefits.

“Although vitamin E and selenium are antioxidants that are found in the eye and have been variously touted as supplements that reduce the risk of cataracts, we found no evidence that either had such an effect,” said Dr. Ian Thompson, director of the UT Health Science Center’s Cancer Therapy and Research Center, who led the local arm of the study.

The Selenium and Vitamin E Cancer Prevention Trial, or SELECT, began in 2001 and followed more than 35,000 men age 50 and older in North America, including about 100 in San Antonio. It was designed to look at whether either supplement prevented prostate cancer. The study was stopped in early 2008 after becoming apparent they did not.

More than 11,000 participants in the overall study also took part in the eye study. They were randomly selected to take either a 400 IU dose of vitamin E daily, 200 micrograms of selenium daily, or a placebo.

Over about 5½ years, 389 men developed cataracts. There was virtually no difference in the risk of cataracts among men in the vitamin E group versus those taking placebo. Of the men taking selenium, 185 developed cataracts compared to 204 in the placebo group — statistically a similar number.

“Our very large study shows that no recommendation can be made for either selenium or vitamin E to reduce the risk of cataracts,” Dr. Thompson said.

Photo courtesy National Eye Institute