Purpose: We assessed the associations of serum, red blood cell membranes (RBCM) and dietary long-chain n-3 polyunsaturated fatty acids (LC-PUFAs) with neovascular age-related macular degeneration (AMD).
Methods: We included 290 patients of the Nutritional AMD Treatment 2 Study (NAT2) with neovascular AMD in one eye and early AMD lesions in the other eye, and 144 normal vision controls without AMD. Dietary intake of seafood was estimated by food frequency questionnaire. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) composition in serum and RBCM were determined by gas chromatography from 12-hour fasting blood samples and was expressed as percentages of total fatty acids profile. Logistic regressions estimated associations of neovascular AMD with dietary intake of seafood and circulating n-3 LC-PUFAs.
Results: Dietary oily fish and seafood intake were significantly lower in AMD patients than in controls. After adjustment for all potential confounders (age, sex, CFH Y402H, ARMS2 A69S, and ApoE4 polymorphisms, plasma triglycerides, hypertension, hypercholesterolemia, and family history of AMD), serum EPA was associated significantly with a lower risk for neovascular AMD (odds ratio [OR] = 0.41; 95% confidence interval [CI], 0.22-0.77; P = 0.005). Analysis of RBCM revealed that EPA and EPA+DHA were associated significantly with a lower risk for neovascular AMD (OR = 0.25; 95% CI, 0.13-0.47; P < 0.0001 and OR = 0.52; 95% CI, 0.29-0.94; P = 0.03, respectively).
Conclusions: The RBCM EPA and EPA+DHA, as long-term biomarkers of n-3 dietary PUFA status, were associated strongly with neovascular AMD and may represent an objective marker identifying subjects at high risk for neovascular AMD, who may most benefit from nutritional interventions. (http://www.controlled-trials.com/isrctn number, ISRCTN98246501).
Keywords: age-related macular degeneration; case-control study; epidemiology; omega-3 fatty acids.