Fish consumption and CHD mortality: an updated meta-analysis of seventeen cohort studies

Objective: Results of studies on fish consumption and CHD mortality are inconsistent. The present updated meta-analysis was conducted to investigate the up-to-date pooling effects. Design: A random-effects model was used to pool the risk estimates. Generalized least-squares regression and restricted cubic splines were used to assess the possible dose-response relationship. Subgroup analyses were conducted to examine the sources of heterogeneity. Setting: PubMed and ISI Web of Science databases up to September 2010 were searched and secondary referencing qualified for inclusion in the study. Subjects: Seventeen cohorts with 315 812 participants and average follow-up period of 15.9 years were identified. Results: Compared with the lowest fish intake (<1 serving/month or 1-3 servings/month), the pooled relative risk (RR) of fish intake on CHD mortality was 0.84 (95% CI 0.75, 0.95) for low fish intake (1 serving/week), 0.79 (95% CI 0.67, 0.92) for moderate fish intake (2-4 servings/week) and 0.83 (95% CI 0.68, 1.01) for high fish intake (>5 servings/week). The dose-response analysis indicated that every 15 g/d increment of fish intake decreased the risk of CHD mortality by 6% (RR = 0.94; 95% CI 0.90, 0.98). The method of dietary assessment, gender and energy adjustment affected the results remarkably. Conclusions: Our results indicate that either low (1 serving/week) or moderate fish consumption (2-4 servings/week) has a significantly beneficial effect on the prevention of CHD mortality. High fish consumption (>5 servings/week) possesses only a marginally protective effect on CHD mortality, possibly due to the limited studies included in this group.