PURPOSE: To examine associations between adherence to a Mediterranean diet and prevalence of age-related macular degeneration (AMD) in countries ranging from Southern to Northern Europe.
DESIGN: Cross-sectional, population-based epidemiologic study.
PARTICIPANTS: Of 5060 randomly sampled people aged 65 years or older from 7 study centers across Europe (Norway, Estonia, United Kingdom, France, Italy, Greece, and Spain), full dietary data were available in 4753. The mean age of participants was 73.2 years (standard deviation, 5.6), and 55% were women.
METHODS: Participants underwent an eye examination and digital retinal color photography. The images were graded at a single center. Dietary intake during the previous 12 months was assessed by using a semiquantitative food-frequency questionnaire (FFQ). A previously published Mediterranean Diet Score (MDS) was used to classify participants according to their responses on the FFQ. Multivariable logistic regression was used to investigate the association of the MDS score and AMD, taking account of potential confounders and the multicenter study design.
MAIN OUTCOME MEASURES: Images were graded according to the International Classification System for age-related maculopathy and stratified using the Rotterdam staging system into 5 exclusive stages (AMD 0-4) and a separate category of large drusen (≥125 μm). Age-related macular degeneration 4 included neovascular AMD (nvAMD) and geographic atrophy (GA).
RESULTS: Increasing MDS was associated with reduced odds of nvAMD in unadjusted and confounder-adjusted analysis. Compared with the lowest MDS adherence (≤4 score), those in the highest category MDS adherence (>6 score) showed lower odds of nvAMD (odds ratio, 0.53; 0.27-1.04; P trend = 0.01). The association with MDS did not differ by Y204H risk allele (P = 0.89). For all early AMD (grade 1-3), there was no relationship with MDS (P trend = 0.9). There was a weak trend (P = 0.1) between MDS and large drusen; those in the highest category of MDS had 20% reduced odds compared with those in the lowest (P = 0.05).
CONCLUSIONS: This study adds to the limited evidence of the protective effect of adherence to a Mediterranean dietary pattern in those with late AMD, although it does not support previous reports of a relationship with genetic susceptibility. Interventions to encourage the adoption of the Mediterranean diet should be developed, and methods by which such behavior change can be achieved and maintained investigated.