Fish Consumption and the Risk of Chronic Disease: An Umbrella Review of Meta-Analyses of Prospective Cohort Studies.

We aimed to present a comprehensive review of published meta-analyses of prospective cohort studies on the association of fish consumption and the risk of chronic disease. A systematic search was undertaken in Pubmed and Scopus to October 2019 to find meta-analyses of observational studies evaluating the association of fish consumption and the risk of chronic disease. Retrospective and cross-sectional studies and studies with unadjusted risk estimates were excluded. The summary relative risk (SRR) for each meta-analysis was recalculated by using a random-effects model. The methodological quality of included meta-analyses and the quality of the evidence were assessed by the AMSTAR and NutriGrade tools, respectively. A total of 34 meta-analyses of prospective observational studies, reporting SRRs for 40 different outcomes obtained from 298 primary prospective cohort studies, were included. Moderate-quality evidence suggested that each 100-g/d increment in fish consumption was associated with a lower risk of all-cause mortality (SRR: 0.92; 95% CI: 0.87, 0.97), cardiovascular mortality (SRR: 0.75; 95% CI: 0.65, 0.87), coronary heart disease (SRR: 0.88; 95% CI: 0.79, 0.99), myocardial infarction (SRR: 0.75; 95% CI: 0.65, 0.93), stroke (SRR: 0.86; 95% CI: 0.75, 0.99), heart failure (SRR: 0.80; 95% CI: 0.67, 0.95), depression (SRR: 0.88; 95% CI: 0.79, 0.98), and liver cancer (SRR: 0.65; 95% CI: 0.48, 0.87). For cancers of most sites, there was no significant association and the quality of the evidence was rated low and very low. In conclusion, evidence of moderate quality suggests that fish consumption is associated with a lower risk of cardiovascular disease, depression, and mortality and, therefore, can be considered as a healthy animal-based dietary source of protein. Further research is needed for outcomes for which the quality of the evidence was rated low and very low, considering types of fish consumed, different methods of cooking fish, and all potential confounding variables.