Abstract
Purpose:
High dietary intake of omega3 polyunsaturated fatty acids (n-3 PUFAs) and fish have been consistently associated with a decreased risk for age-related macular degeneration (AMD). We report the associations of neovascular AMD with omega-3 serum and red-blood cell membranes (RBCM) n-3 PUFAs, which represent a more objective assessment of n-3 PUFAs status.
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 using a 165 items, semi-quantitative, food frequency questionnaire (FFQ). Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) composition in serum and RBCM were determined by gas chromatography from 12h-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 PUFAs. The omega 3 index was calculated as RBCM EPA+DHA.
Results:
In AMD patients as well as in controls, serum and RBCM n-3 LC-PUFAs closely reflected type of seafood intake, while they appeared independent from medical, lifestyle or genetic markers of AMD. Dietary oily fish and seafood intake were significantly lower in AMD patients than in controls, consistent with an omega-3 index <4 (RBCM EPA+DHA = 3.8 (2.1-5.9) AMD versus 4.3 (2.6-6.5) controls, p=0.001). After adjustment for all potential confounders (age, gender, CFH Y402H, ARMS2 A69S, and ApoE4 polymorphisms, plasma triglycerides, hypertension, hypercholesterolemia and family history of AMD), serum EPA was significantly associated with a lower risk for neovascular AMD (OR=0.41 (0.22-0.77); p=0.005). Analysis of RBCM revealed that EPA and EPA+DHA were significantly associated with a lower risk for neovascular AMD (OR=0.25 (0.13-0.47); p<0.0001 and OR=0.52 (0.29-0.94); p=0.03, respectively).
Conclusions:
RBCM EPA and EPA+DHA, as long-term biomarkers of n-3 dietary PUFA status, were strongly associated with neovascular AMD and may represent an objective marker identifying subjects at high risk for neovascular AMD, whom may most benefit from nutritional interventions.
Keywords: 412 age-related macular degeneration •
618 nutritional factors •
464 clinical (human) or epidemiologic studies: risk factor assessment