The United States National Eye Institute performed two prospective evaluations of thousands of people with macular degeneration, called the Age-Related Eye Disease Studies, or "AREDS."
The initial AREDS research in 2001 showed that five ingredients were more effective than placebo in slowing the progression of macular degeneration. These ingredients included beta-carotene, Vitamin C and E, and the minerals zinc and copper.
The subsequent AREDS 2 research showed some improvement over the original AREDS. Its findings are summarized below: