Intake of Fish and n-3 Fatty Acids and Future Risk of Metabolic Syndrome

Background: Whether or not fish and n-3 fatty acid intake is associated with the metabolic syndrome risk has not been carefully evaluated. This study investigated the effect of fish and n-3 fatty acid intake on the incidence of metabolic syndrome and on the individual risk factors for the syndrome. Methods: A population-based prospective cohort study included 3,504 male and female Koreans aged 40 to 69 years from the Korean Genome Epidemiology Study. At the beginning of follow-up, all individuals were free of metabolic syndrome and known cardiovascular disease. Each participant completed a food frequency questionnaire. Incident cases of metabolic syndrome were identified by biennial health examinations during a follow-up period between April 17, 2003, and November 17, 2006. Pooled logistic regression analysis was applied to obtain an odds ratio (OR) of metabolic syndrome with its 95% confidence interval (CI) for fish or n-3 fatty acid intake. Results: After controlling for potential cardiovascular risk factors, multivariate OR for metabolic syndrome was 0.43 (95% CI 0.23 to 0.83) for men who ate fish daily when compared with those eating fish less than once a week. Similarly, metabolic syndrome risk was halved for men in the top decile of n-3 fatty acid intake when compared with those in the bottom decile (OR 0.53, 95% CI 0.28 to 0.99). In particular, fish intake was significantly associated with triglyceride level and high-density lipoprotein cholesterol level among the metabolic syndrome components. For women, apparent associations were not observed between fish intake or n-3 fatty acid intake and metabolic syndrome risk. Conclusions: In a prospective study, high consumption of fish and n-3 fatty acids was significantly associated with a lower risk of metabolic syndrome among men, but not among women. Whether or not encouraging fish intake can help prevent the development of metabolic syndrome warrants further studies.