Associations of Fish Consumption With Risk of Cardiovascular Disease and Mortality Among Individuals With or Without Vascular Disease From 58 Countries

Abstract

Dietary guidelines recommend at least 2 servings of fish per week for the prevention of cardiovascular disease (CVD).^1,2 Fish is a major source of the long-chain ω-3 fatty acids docosahexaenoic acid and eicosapentaenoic acid, which have been suggested to have beneficial effects on cardiovascular health.^3-5 In interventional studies, fish and ω-3 consumption have been shown to improve some cardiovascular risk markers, including triglycerides and blood pressure, especially in people with triglycerides of 500 mg/dL or greater (to convert to millimoles per liter, multiply by 0.0113).^6,7 Two recent meta-analyses of randomized trials in high-risk individuals showed that ω-3 supplementation (typically approximately 1 g/d) was not associated with risk of cardiovascular events, coronary heart deaths, coronary heart disease events, stroke, heart irregularities, or all-cause mortality.^8,9 By contrast, another recent meta-analysis¹⁰ that included 3 new trials^11-13 showed that ω-3 supplementation was associated with significant benefit against risk of CVD outcomes (summary relative risk of 0.92; 95% CI, 0.86-0.98),¹⁰ even after excluding a recent trial of patients with elevated triglyceride levels that used a much higher dose of fish oil (4 g daily).¹³ Observational cohorts of participants without diagnosed vascular disease have found modest protective associations of moderate fish consumption (approximately ≥2 servings/wk) with fatal coronary heart disease (ie, summary relative risks in multiple meta-analyses ranging from 2% to 15% lower risk) and, usually less strongly, with total CVD.¹⁴ To date, most cohort studies evaluating fish consumption and CVD events have been conducted in Europe, North America, Japan, and China, with little information from other world regions, where varying amounts and types of fish are consumed. Furthermore, whether the associations of fish consumption with CVD events vary between those with and those without vascular disease is unclear.