The first Age-Related Eye Disease Study (AREDS) showed that the AREDS formulation of vitamin and mineral supplements consisting of vitamin C, vitamin E, beta-carotene (an anti-oxidant), and zinc can reduce the risk of progression in age-related macular degeneration (AMD).
The second study, AREDS2, was developed to determine the effects of adding omega-3 fatty acids, replacing beta-carotene with lutein and zeaxanthin, and lowering the dose of zinc in people at risk for progression of AMD. The results of the study found that the addition of omega-3 fatty acids had no significant effect on progression of AMD, nor did the reduction of the zinc dosage. People who took the AREDS formulation with lutein and zeaxanthin, but without beta-carotene, reduced their risk of progression of AMD by 18% compared with those who took the AREDS formulation with beta-carotene, but without lutein or zeaxanthin. People who had very low intake of lutein and zeaxanthin in their diet and who took lutein and zeaxanthin in their supplements had a further lowered risk of progression of AMD. People who had formerly smoked and who took beta-carotene had an increased risk of lung cancer; there was no increase associated with lutein and zeaxanthin.
In summary, the results of these two studies indicate that people who are at risk for progression of AMD can further reduce their risk by taking the AREDS dietary supplement with lutein and zeaxanthin, without beta-carotene. Although beta-carotene does not appear to pose a risk of lung cancer to people who have never smoked, lutein and zeaxanthin do not increase the risk of lung cancer regardless of smoking history. Omega-3 fatty acid supplements did not have any effect in this study, but they are still valuable and necessary nutrients. Also, the intake of these nutrients in their food sources, such as fish and leafy green vegetables, is associated with better overall health as well as eye health.