Fish Oil Cuts Risk of Geographic Atrophy in Half: AREDS Report No. 23 A new report from the AREDS study group report that dietary ω-3 long-chain polyunsaturated fatty acid (fish oil) intake is associated with a 50% decreased risk of progression from bilateral drusen to central geographic atrophy (CGA). A reduced likelihood of progression from bilateral drusen to CGA was found among people who reported the highest levels of EPA and EPA+DHA consumption.

Docosahexaenoic acid (DHA), the major dietary and structural ω-3 long-chain polyunsaturated fatty acid (LCPUFA) of the retina, has the capacity to modulate processes implicated in AMD pathogenesis. Eicosapentaenoic acid (EPA), the precursor to DHA and the other major dietary ω-3 LCPUFA, can exert similar actions to DHA.

Report 20 from the Age-Related Eye Disease Study (AREDS) describes a 40% to 50% reduced likelihood of having neovascular (NV) AMD among participants who reported the highest levels of ω-3 LCPUFA consumption; these findings are concordant with those from other studies examining relationships of ω-3 LCPUFAs and ω-3 LCPUFA-rich food intake with various stages of incident and prevalent AMD. Although statistical relationships did not always exist in these studies, measures of association were consistently in the direction of benefit. Higher levels of ω-3 LCPUFA and fish intake were associated with a decreased likelihood of progression to advanced AMD in subgroups from the 2 published studies examining this issue.

The investigators analyzed 2132 AREDS category 2 and 3a participants who responded to the AREDS Food Frequency Questionnaire (FFQ) at baseline. Categories 2 and 3a; participants in these categories had bilateral visual acuity of 20/32 or better. Category 2 participants had mild or borderline age-related macular changes (small drusen or intermediate drusen and/or pigment abnormalities). Category 3a participants had large drusen, extensive intermediate drusen, and/or geographic atrophy (GA) that did not involve the center of the macula. This study population was chosen to represent participants at mild-to-moderate risk of progression to advanced AMD in both eyes. Median follow-up was 6.3 (range, 1-8) years.

CGA developed in 113 participants. Participants who reported the highest levels of DHA intake were half as likely to experience progression to CGA as those who reported the lowest intake. Participants who reported the highest EPA intake and EPA+DHA intake were 60% less likely to progress to CGA.

Neovascular AMD developed in 198 participants. No relationships of EPA, DHA, or EPA+DHA intake with incident NV AMD were observed. People who reported the most frequent tuna intake were approximately half as likely to experience progression to NV AMD as those who reported the least frequent intake.

This study is the first to report separate outcomes on progression to NV AMD and CGA as they may relate to ω-3 LCPUFA intake. Associations of nutrients and AMD attained statistical significance for CGA only. The absence of an association between ω-3 LCPUFA intake and NV AMD is unexpected in the context of emerging evidence. AREDS2, a 4000-person randomized clinical trial, is designed to examine the efficacy of ω-3 LCPUFA supplementation on prevention of progression to CGA and NV AMD and should help shed light on this issue.

The investigators conclude that participants with bilateral drusen who reported the highest levels of EPA and EPA+DHA intake had a 50% decreased likelihood of progression to CGA relative to their peers.

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Arch Ophthalmol. 2008;126(9):1274-1279.