Fish consumption and risk of myocardial infarction: a systematic review and dose-response meta analysis suggests a regional difference

Limited evidence suggests that the association between fish consumption and risk of cardiovascular disease may be confounded by some regional-related factors. We aimed to quantify the association of fish consumption with risk of myocardial infarction (MI) and to clarify the shape of the dose-response relation in Western and Asian countries. A systematic literature review was performed in PubMed and Scopus from inception to January 2018. Prospective observational studies reporting risk estimates of MI for 3 or more quantitative categories of fish intake were included. A random-effects dose-response meta-analysis was conducted. Eleven prospective cohort studies, comprising a total of 398,221 participants and 8468 cases of MI, were analyzed. A significant inverse association was found for the highest compared with the lowest category of fish intake (relative risk: 0.73, 95% confidence interval: 0.59-0.87; I-2 = 72%) and for a 15-g/d (105 g/wk, approximately equal to a 1 serving/wk) increment in fish consumption (relative risk: 0.96, 95% confidence interval: 0.94-0.99; I-2 = 65%). A subgroup analysis showed a significant inverse association only in the subgroup of Asian studies as compared to Western studies. A nonlinear dose-response analysis suggested a linear decrement in the risk with the increase in fish consumption in the analysis of Asian studies. A modest U-shaped association was observed in the analysis of Western studies. In conclusion, higher fish consumption was associated with a lower risk of MI. However, considering the observed regional difference in this association, further observational studies are needed to provide more detailed explanations about this difference. (C) 2018 Elsevier Inc. All rights reserved.