Vitamin E & Selenium For The Treatment Of Cataracts

Cataracts, a clouding of the lens in the eye that causes vision loss, occurs commonly as people age, affecting more than half of all Americans by the time they reach age 80, according to the National Eye Institute. Surgical lens removal effectively treats the vision loss. Vitamin supplements to prevent cataract progression has had mixed results. Talk with your medical practitioner before taking vitamins to treat cataracts.

Definition

Vitamin E, a fat-soluble vitamin, acts as an antioxidant, protecting cells from damage from free radicals, substances produced by the breakdown of toxins. Selenium, a mineral, appears to increase the absorption of antioxidants such as vitamin E. Giving both together may potentiate vitamin E.

Cataract Formation

The lens in the eye consists mostly of water and protein. As part of the aging process, proteins may start to clump together, causing the lens to turn cloudy. Smoking and having diabetes may worsen cataracts. Ultraviolet light may also contribute to cataract formation. Because vitamin E acts as an antioxidant, it may protect the lens from protein breakdown.

Changes

When a cataract develops, the amount of selenium in the lens of the eye drops to around 15 percent of normal levels, according to the website Protect-Your-Eyesight. The levels of one of the main antioxidant enzymes in the lens, glutathione peroxidase, also drop because its activation requires adequate amounts of selenium.

Studies

A 1998 study conducted by the University Medical Center at Stony Brook found that of 764 people those who took multivitamin supplements decreased their risk of cataract development by 33 percent, while those who took vitamin E supplements and who had higher blood levels of vitamin E reduced their risk by 50 percent. However, a four year study conducted by Monash University in Australia that followed 1,193 people with early or no cataract, found no difference in cataract development in the group taking 500 IU of vitamin E.

In animal trials, selenium has not proven beneficial in preventing cataracts; selenium exacerbated cataracts in some rat studies, according to the EnCognitive website. A current study using data from the SELECT study, which stands for Selenium and Vitamin E Cancer Prevention Trial, which examined the effects of vitamin E and selenium in men with prostate cancer, is ongoing until 2012.

Risks

Because vitamin E is fat-soluble, it can be stored in your body, making it easy to overdose if you take too much. Side effects of vitamin E overdose include impaired blood clotting that can cause excessive bleeding, especially in people who take blood thinners or who have underling bleeding disorders. Do not take vitamin E supplements to treat cataracts without discussing their effect with your physician. Taking more than 800 IU of vitamin E may increase your chances of death "from any cause," meaning that no matter what condition you have, you're more likely to die from it if you take large amounts of vitamin E, a Johns Hopkins University study found. In high doses, selenium can cause nausea, vomiting and loss of energy, among other effects.