COMMENTARY

Do Omega-3 Fatty Acids Help Prevent AMD?

Vaidehi S. Dedania, MD; Sophie J. Bakri, MD

Disclosures

January 16, 2014

In This Article

Study Findings

By the end of the study, 1608 participants had experienced at least 1 advanced AMD event. No statistically significant difference in progression was noted among the primary randomization study groups. In the secondary randomization study groups, no statistically significant effect on progression to advanced AMD was observed with lower doses of zinc and/or with the elimination of beta carotene. Serum levels of lutein at year 5 were lower in patients receiving lutein + zeaxanthin and beta carotene than in patients receiving lutein + zeaxanthin without beta carotene (P = .02). Exploratory secondary analyses of treatment main effect demonstrated a protective effect for lutein + zeaxanthin for progression to advanced AMD, with a 10% reduction beyond that provided by the AREDS1 formulation (P = .05). A protective effect of lutein + zeaxanthin on the progression to advanced AMD was observed in participants in the lowest quintile of dietary lutein + zeaxanthin intake (P = .01). This effect was not demonstrated with increasing dietary lutein + zeaxanthin intake. Post hoc analysis comparing lutein + zeaxanthin and the AREDS1 formulation without beta carotene with the AREDS1 formulation with beta carotene resulted in a statistically significant difference in progression to advanced AMD (P = .02) and neovascular AMD (P = .01), but not to central geographic atrophy (P = .67). This leads us to believe that lutein + zeaxanthin has a protective effect beyond that of beta carotene. Development of moderate or worse vision loss was similar across all 4 treatment groups, and the elimination of beta carotene or reduction in the zinc dose had no effect on vision.

In the primary randomization, there was no statistically significant difference in serious adverse events. However, there were more lung cancers in the beta carotene group than in the no beta carotene group (P = .04) in the secondary randomization, which excluded participants who were current smokers. Of the participants who developed lung cancer, 91% were former smokers. Gastrointestinal disorders and hospitalization for genitourinary disease, previously attributed to high-dose zinc, occurred at similar rates in the low-dose zinc and high-dose zinc treatment groups.

Daily oral supplementation with lutein + zeaxanthin, DHA + EPA, or lutein + zeaxanthin with DHA + EPA in addition to the AREDS1 formulation did not further reduce progression to advanced AMD. No changes in visual acuity were observed with dietary supplementation with lutein + zeaxanthin, DHA + EPA, or lutein + zeaxanthin with DHA + EPA in addition to the AREDS1 formulation. These null results may be attributed to a true lack of efficacy or to factors such as inadequate dose, inadequate treatment duration, and/or competitive absorption of carotenoids. Furthermore, although no statistically significant overall effect was observed in the primary randomization, exploratory analyses suggest a possible beneficial effect in participants taking lutein + zeaxanthin, especially in participants with low serum lutein levels.

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