Purpose
To investigate associations between dietary omega-3 fatty acids and other fat intake, genes related to age-related macular degeneration (AMD) and progression to geographic atrophy (GA).
Methods
Participants included 2531 individuals from the Age-Related Eye Disease Study, among whom 525 eyes progressed to GA and 4165 eyes did not. Eyes without advanced AMD (GA or neovascular disease) at baseline were evaluated for progression to GA. Behavioral data, including smoking and body mass index measurements were collected at baseline. Dietary data was collected from food frequency questionnaires (FFQ) at baseline. Omega-3 fatty acids (docosahexaenoic acid or DHA and eicosapentaenoic acid or EPA), omega-6 fatty acids, monounsaturated, saturated, polyunsaturated and total fat were adjusted for sex and caloric intake and divided into quintiles. Eight SNPs in 7 genes: CFH, ARMS2/HTRA1, CFB, C2, C3, CFI, and LIPC were genotyped. Cox proportional hazards models were used to test for associations between incident GA and intake of dietary lipids, as well as interaction effects between dietary fat intake and genetic variation on risk of GA.
Results
Increased intake of DHA was significantly associated with reduced risk of progression to GA in multivariate models with behavioral factors (Model A) plus genetic variants (Model B) (P trend=0.008 and 0.03, respectively). Omega-3 long chain polyunsaturated (DHA + EPA) fatty acid intake was significantly associated with reduced risk of progression in Model B (P trend =0.02). Monounsaturated fat was associated with increased risk in Model A (P trend=0.05). DHA intake was significantly associated with reduced risk of incident GA among those with the ARMS2/HTRA1 homozygous risk genotype (HR Q5 vs Q1 = 0.4, P = 0.002); DHA was not associated with reduced risk of GA among those with the homozygous non-risk genotype (HR = 1.0, P= 0.90, P interaction between ARMS2 and fat intake = 0.05).
Conclusions
Increased self- reported dietary intake of omega-3 fatty acids is associated with reduced risk of GA and may modify genetic susceptibility for progression to GA.
Keywords: 412 age-related macular degeneration •
464 clinical (human) or epidemiologic studies: risk factor assessment