Genetic Influence of Oily Fish Intake on Age-Related Macular Degeneration Risk: A Two-Sample Mendelian Randomization Analysis.

PURPOSE

Emerging research indicates a link between the intake of fatty fish and age-related macular degeneration (AMD). However, observational studies fall short in establishing a direct causal link between oily fish intake and AMD. We wanted to determine whether causal association lies between oily fish intake and age-related macular degeneration (AMD) risk in human beings.

METHODS

This two-sample mendelian randomization (MR) study used the MR method to probe the genetic causality in the relationship between oily fish intake and AMD. The genome-wide association study (GWAS) data for AMD were acquired from a Finnish database, whereas the data on fish oil intake came from the UK Biobank. The analysis used several approaches such as inverse-variance weighted (IVW), MR Egger, weighted median, simple mode, and weighted mode MR. In addition, the Cochran's Q test was used to evaluate heterogeneity in the MR data. The MR-Egger intercept and MR-pleiotropy residual sum and outlier (MR-PRESSO) tests were used to assess the presence of horizontal pleiotropy. A leave-one-out sensitivity analysis was conducted to determine the reliability of the association.

RESULTS

The IVW method revealed that the intake of oily fish is an independent risk factor for AMD (P = 0.034). It also suggested a minimal likelihood of horizontal pleiotropy affecting the causality (P > 0.05), with no substantial heterogeneity detected in the genetic variants (P > 0.05). The leave-one-out analysis confirmed the reliability and stability of this correlation.

CONCLUSIONS

This research used a two-sample MR analysis to provide evidence of a genetic causal relationship between the eating of oily fish and AMD. This discovery held potential significance in AMD prevention.