Associations between the Mediterranean lifestyle and incident age-related eye diseases: a longitudinal analysis from the UK Biobank

Background: The Mediterranean lifestyle (MEDLIFE) is generally considered to have a positive effect on several health outcomes. However, little is known about its impact on age-related eye diseases. We aimed to assess the effect of MEDLIFE on the risk of three such diseases: cataract, glaucoma, and age-related macular degeneration (AMD). Methods: We included 113 829 participants from the UK Biobank who were free of age-related eye diseases at baseline and followed them up prospectively for disease occurrence. Adherence to MEDLIFE was assessed using 25 items, categorised under three blocks: 'Mediterranean food consumption' (block 1), 'Mediterranean dietary habits' (block 2), and 'physical activity, rest, social habits' (block 3). We used a Cox proportional hazard model to examine the associations of the MEDLIFE index and each of its blocks with incident age-related eye diseases. Results: During a median follow-up of 10.5 years, 9954 cases of cataract, 1956 cases of glaucoma, and 1736 cases of AMD were identified. We noted an inverse association between the MEDLIFE index and new-onset cataract (P-value for trend = 0.005). A one-point increment in the MEDLIFE score was associated with a 1.5% (95% confidence interval (CI) = 0.7-2.3) reduction in the risk of cataract, and with a 2.4% (95% CI = 0.5-4.3) reduction in AMD incidence. Analysis of MEDLIFE blocks indicated that block 2 (hazard ratio (HR) = 0.97; 95% CI = 0.95-0.99) and block 3 (HR = 0.97; 95% CI = 0.95-0.99) were associated with lower risk of cataract. Block 2 was further related to reduced risk of AMD (HR = 0.95; 95% CI = 0.91-0.99). Although we found no association between the MEDLIFE index and incident glaucoma, block 3 was associated with lower glaucoma risk (HR = 0.94; 95% CI = 0.90-0.98). Conclusions: Higher adherence to MEDLIFE was associated with decreased incidence of cataract and AMD, while the 'physical activity, rest, and social interactions' block was related to a lower risk of glaucoma. Our findings suggest that MEDLIFE may serve as a potential behavioural intervention for preventing age-related eye diseases.