Association of genetics and the adherence to the Mediterranean diet: the risk for age-related macular degeneration

Abstract

Purpose : To explore the association of the genetic risk score (GRS) for the onset of Age-Related Macular Degeneration (AMD) with the adherence to the Mediterranean diet (MedDiet) – the Coimbra Eye Study (CES).

Methods : 612 subjects (161cases/451 controls) who completed a validated lifestyle and food frequency questionnaire were genotyped in collaboration with the European Eye Epidemiology Consortium. Cases were participants staged 2, 3 or 4 and controls were participants staged 0 (> 60 years-old) or 1 (> 70 years-old), Rotterdam Classification. The adherence to the MedDiet was calculated with mediSCORE (range 0-9) calculated by the sum of nine food group: vegetables, legumes, fruits, cereals, fish, meat, dairy products, fats and alcohol. High adherence to the MedDiet was defined as a mediSCORE equal or >6 (range: 6–9). A GRS was calculated using the 52 single nucleotide polymorphism identified by the International AMD Genomics Consortium. GRS was considered missing if at least one genotype of the major risk variants (CFH rs570618, CFH rs10922109, C2/CFB/SKIV2L rs429608, ARMS2 rs3750846 or C3 rs2230199) was missing. High GRS was classified as greater than or equal to the median. A multivariate logistic regression model with generalized estimating equations for 1216 individual eyes was used to examine the association of AMD, GRS and mediSCORE, controlled by age, sex, smoking and physical exercise.

Results : A higher adherence to the MedDiet was significantly associated with a decreased risk of AMD (OR=0.61, 95%CI 0.39-0.94, p=0.024) and a higher GRS was significantly associated with an increased risk of AMD (OR=2.44, 95%CI 1.66-3.58, p<0.0001). However, no statistical significant interaction was found between the GRS and MedDiet (p=0.284). Despite this, the adherence to the MedDiet was found to be protective for AMD in people with low GRS (OR=0.44, 95%CI 0.21-0.94, p=0.034), while no benefit was observed for people whose GRS was high (OR=0.70, 95%CI 0.40-1.22, p=0.212).

Conclusions : The MedDiet may be protective against the development of AMD, and this protection may depend on the genetic risk. However, it is crucial to carry out further studies on different populations, to clarify the interplay of AMD risk factors, particularly on the MedDiet, in the establishment of the pathophysiology of the disease.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.