Participants were randomized to receive lutein (10 mg) and zeaxanthin (2 mg), DHA (350 mg) + EPA (650 mg), lutein + zeaxanthin and DHA + EPA, or placebo. All participants were also asked to take the original AREDS formulation or accept a secondary randomization to 4 variations of the AREDS formulation, including elimination of beta carotene, lowering of zinc dose, or both.
A total of 1,608 participants had experienced at least 1 advanced AMD event by the end of the study (1,940 events in 6,891 study eyes). The researchers found that the probabilities of progression to advanced AMD by 5 years were 31 percent for placebo, 29 percent for lutein + zeaxanthin, 31 percent for DHA + EPA, and 30 percent for lutein + zeaxanthin and DHA + EPA. In the primary analyses, comparisons with placebo demonstrated no statistically significant reductions in progression to advanced AMD.
"There was no apparent effect of beta carotene elimination or lower-dose zinc on progression to advanced AMD. More lung cancers were noted in the beta carotene vs. no beta carotene group (23 [2 percent] vs. 11 [0.9 percent]), mostly in former smokers," the authors write.
None of the nutrients affected development of moderate or worse vision loss.
The researchers add that "these null results may be attributable to the true lack of efficacy. Other factors to consider include inadequate dose, inadequate duration of treatment, or both."
"Based on apparent risks of beta carotene and possible benefits that are only
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