The AREDS study evaluated the effect of certain vitamins and supplements on vision loss and progression of dry age-related macular degeneration (dry ARMD). The original AREDS formulation was composed of:
- 500 mg of vitamin C
- 400 IU of vitamin E
- 15 mg of beta-carotene
- 80 mg of zinc
- 2 mg of cupric oxide
The AREDS study concluded that patients with intermediate and advanced ARMD (defined by extensive intermediate drusen, at least one large drusen, or geographic atrophy) who received the AREDS formulation had a 25% decrease in risk of disease progression and 19% decrease in risk of vision loss at 5 years compared to the control group.
The subsequent AREDS2 study investigated the effect of omega-3 fatty acids and the antioxidants lutein and zeaxanthin on ARMD. Lutein and zeaxanthin were substituted for beta-carotene, which in prior studies had been associated with increased risk of lung cancer among smokers. AREDS2 found that while omega-3 fatty acids had no effect on ARMD, lutein and zeaxanthin were a safe and effective alternative to beta-carotene.