The researchers concluded that high levels of antioxidants and zinc can reduce some people's risk of developing advanced AMD by about 25 percent.
Studies in 2016[3] and 2018[4] later showed that this average 25 percent reduction in risk from the combination of anti-oxidants and zinc varies by genotype.
The original AREDS study was followed by AREDS2, a five-year study that started in 2006 to test whether the original AREDS formulation would be improved by adding omega-3 fatty acids; adding lutein and zeaxanthin; removing beta-carotene; or reducing zinc.
[6][8] The study reported that there was no overall additional benefit from adding omega-3 fatty acids or lutein and zeaxanthin to the formulation.
[9] According to Dr. Emily Chew, "Because carotenoids can compete with each other for absorption in the body, beta-carotene may have masked the effect of the lutein and zeaxanthin in the overall analysis.