New Study Finds That Supplements Help People with Age-related Macular Degeneration Keep Their Vision

The Age-Related Eye Disease Study (AREDS) was a major study sponsored by the National Eye Institute and conducted at 11 medical research centers around the country. This large-scale clinical trial was undertaken because age-related macular degeneration (AMD) is the leading cause of vision impairment among people 65 and older, and because the treatments for preventing its advanced forms are very limited. Started in 1992, the results of this study were reported in mid-October.

Over 3,600 older participants were followed for about six years during the trial. Patients were initially assigned to different categories based on the extent and type of their disease from early to intermediate, and more advanced stages of AMD. They then received one of four supplements: a placebo, high-dose zinc with copper and antioxidants (vitamins C, E and beta-carotene), or a combination of zinc and copper plus the antioxidants.

Both the antioxidants and the mineral supplements each appeared to offer protection. But the benefits were greatest for those who received the antioxidant and zinc combination, and who were in the highest-risk categories (patients with intermediate and advanced forms). Supplementation with antioxidants and zinc significantly reduced the risk of progressing to more advanced AMD in these groups by 25%, and reduced their risk of vision loss by 27%.

The study was not able to show that supplements could prevent AMD, or restore vision already lost. But supplements can play a key role in helping people at risk for advanced AMD curb its advancement and preserve their vision. With the caveats that high dose beta-carotene should be avoided by smokers and ex-smokers, and that supplement takers need to be routinely monitored, the study confirmed the general safety and benefit of these high-potency supplements in maintaining vision.

While the researchers considered including lutein along with vitamins C and E, this carotenoid was not available when the study started. Instead they chose beta-carotene, which was being studied at the time in heart disease.

Reference

1. Age-Related Eye Disease Study Research Group. A Randomized, Placebo-Controlled, Clinical Trial of High-Dose Supplementation with Vitamins C and E, Beta Carotene, and Zinc for Age-Related Macular Degeneration and Vision Loss. Arch Ophthalmol 119:1417-36, 2001.