Adherence to the Mediterranean Diet and Progression to Late Age-Related Macular Degeneration in the Age-Related Eye Disease Studies 1 and 2.

PURPOSE: To determine whether closer adherence to a Mediterranean diet (and its individual components) was associated with altered risk of progression to late age-related macular degeneration (AMD) and large drusen. Additional objectives were to assess interactions with AMD genotype. DESIGN: Retrospective analysis of 2 controlled clinical trial cohorts: Age-Related Eye Disease Study (AREDS) and AREDS2. PARTICIPANTS: Eyes with no late AMD at baseline in AREDS participants (n = 4255) and AREDS2 participants (n = 3611): total of 13 204 eyes (7756 participants). Mean age was 71 years (standard deviation, 6.6); 56.5% were female. METHODS: Color fundus photographs were collected at annual study visits and graded centrally for late AMD. The modified Alternative Mediterranean Diet Index (aMedi) score was calculated for each participant from food frequency questionnaires. MAIN OUTCOME MEASURES: Progression to late AMD, geographic atrophy (GA), and neovascular AMD; progression to large drusen. RESULTS: Over a median follow-up of 10.2 years, of the 13 204 eyes, 34.0% progressed to late AMD. Hazard ratios (HRs) for progression in aMedi tertile 3 versus 1 were 0.78 (95% confidence interval [CI], 0.71-0.85, P < 0.0001) for late AMD, 0.71 (0.63-0.80, P < 0.0001) for GA, and 0.84 (0.75-0.95, P = 0.005) for neovascular AMD. For fish consumption, HRs for late AMD in quartile 4 versus 1 were 0.69 (0.58-0.82, P < 0.0001; AREDS) and 0.92 (0.78-1.07, P = 0.28; AREDS2). In AREDS, both aMedi and its fish component interacted with CFH rs10922109 for late AMD (P = 0.01 and P = 0.0005, respectively); higher aMedi and fish intake were each associated with decreased risk only in participants with protective alleles. In separate analyses (n = 5029 eyes of 3026 AREDS participants), the HR for progression to large drusen in aMedi tertile 3 versus 1 was 0.79 (0.68-0.93, P = 0.004). CONCLUSIONS: Closer adherence to a Mediterranean-type diet was associated with lower risk of progression to late AMD and to large drusen. The signal was greater for GA than neovascular AMD. Fish intake contributed to this protective association. CFH genotype strongly influenced these relationships. These findings may help inform evidence-based dietary recommendations.