Dietary Antioxidant Intake Reduces Risk of AMD. The Rotterdam Study.

Abstract

Abstract: : Purpose: To study the association between baseline dietary antioxidant intake and incident ageing macular disease (iAMD) in a population–based setting. Methods:In 4139 independently living subjects with normal cognition, at risk for both early and late iAMD food intake was analyzed at baseline by a two–step food–frequency questionnaire. Respondents filled in at home a checklist of food and drink items that they had ingested at least twice a month over the last year. Next they were interviewed by a dietician based on this checklist using a semi–quantitative food frequency questionnaire. Data were converted to total energy and nutrient intake using the computerized Netherlands Food Composition Table. AMD was graded on color stereo fundus transparencies according to the international classification system. Odds ratios (ORs) were calculated with logistic regression analysis adjusted for follow–up time and usual confounders. Results: After a mean follow–up of 5.3 years iAMD was found in 362 subjects. Per standard deviation of increased intake of vitamin E the OR for iAMD was 0.88 (95%CI 0.78–0.99), for iron 0.83 (0.74–0.93), for zinc 0.85 (0.76–0.96). Apart from iron these associations also were present when highest versus lowest quartiles were compared. Below–median dietary ingestion of the AREDS supplement contents (vitamins C and E, beta–carotene, zinc) significantly increased the risk of AMD by 33%, above–median ingestion decreased it by 56%. Exclusion of subjects using dietary supplements (13.4%) did not significantly change the results. Conclusions:High dietary intake of antioxidants reduces and low intake raises the risk of iAMD. The optimum (dietary) dose still has to be established.

Keywords: antioxidants • age–related macular degeneration • nutritional factors