https://doi.org/10.1016/j.ophtha.2024.12.005
This study investigated the potential protective effects of omega-3 fatty acids on age-related macular degeneration (AMD) using both a prospective cohort study and Mendelian randomization (MR) analyses.
The cohort study included 258,350 AMD-free individuals of European descent from the UK Biobank, with plasma omega-3 and docosahexaenoic acid (DHA) measurements.
Over a 12.9-year follow-up, 5,068 (1.9%) participants developed AMD. Higher plasma levels of omega-3 and DHA were associated with a lower risk of AMD diagnosis, with hazard ratios of 0.80 and 0.65 respectively.
The MR analyses used genome-wide association study data on plasma omega-3/DHA levels and AMD from large databases. These analyses showed causal relationships between genetic predisposition to higher plasma omega-3 levels and lower risk of dry AMD, wet AMD, and any AMD. Similarly, genetic predisposition to higher DHA levels was causally associated with lower risk of wet AMD and any AMD.
The study adjusted for systemic covariates and AMD polygenic risk score in the cohort analysis. It also tested for interaction effects between omega-3/DHA levels and genetic risk factors but found no significant interactions.
Multiple MR models were used to ensure robustness of the causal inferences. Overall, both the prospective cohort and MR analyses suggest a protective effect of omega-3 and DHA on AMD risk. The authors conclude this supports the need for further clinical trials to test the effectiveness of omega-3 fatty acids in AMD prevention and treatment.
The study’s strengths include its large sample size, long follow-up, and use of both observational and genetic approaches to examine causality.
