Dietary supplements reduce risk of vision loss from AMD, study says

BETHESDA, Md. — A dietary supplement of high levels of antioxidants and zinc significantly reduces the risk of advanced age-related macular degeneration (AMD) and its associated vision loss, according to a recent study.

The findings from a nationwide clinical trial, reported in the October issue of Archives of Ophthalmology, states that people at high risk of developing advanced stages of AMD lowered their risk by about 25% when treated with a high-dose combination of vitamin C, vitamin E, beta carotene and zinc. In the same high risk group — which includes people with intermediate AMD, or advanced AMD in one eye but not the other eye — the supplements reduced the risk of vision loss caused by advanced AMD by about 19%. For those participants who had either no AMD or early AMD, the supplements did not provide an apparent benefit.

The supplements evaluated by the Age-Related Eye Disease Study (AREDS) contained 500 milligrams of vitamin C; 400 IU of vitamin E; 15 milligrams of beta carotene; 80 milligrams of zinc as zinc oxide; and 2 milligrams of copper as cupric oxide. Copper was added to the AREDS formulations containing zinc to prevent copper deficiency, which may be associated with high levels of zinc supplementation, according to researchers. The National Eye Institute, sponsor of the AREDS, collaborated with Bausch & Lomb in this study. The company provided the supplements evaluated by the AREDS researchers and financially supported the laboratory testing and distribution of medications.

The AREDS involved 4,757 participants 55 to 80 years of age in 11 clinical centers nationwide. Participants in the study were given one of four treatments: 1) zinc alone; 2) antioxidants alone; 3) a combination of antioxidants and zinc; or 4) a placebo.

In the cataract portion of the study, researchers discovered that the same supplements had no significant effect on the development or progression of age-related cataract.