Chapter 8 – More Fish, Less Meat

Epidemiological evidence suggesting a protective effect of fish intake on cardiovascular disease dates back to ecological studies from the 1970s. Since then, it has become clear that the specific nutritional composition of fish, namely, its high levels of two long-chain omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), confer strong cardiovascular benefits. Intermediary physiological benefits of fish intake via EPA and DHA include lowering plasma triglycerides, reducing heart rate and blood pressure, improving myocardial filling and efficiency, decreasing inflammation, and antiarrhythmic effects. Prospective observational studies and randomized controlled trials have consistently found that fish intake is associated not only with these intermediary benefits but with major reductions in several cardiovascular disease outcomes, most notably coronary heart disease mortality. Conversely, meat intake is associated with increased risk of cardiovascular disease, likely due to its high saturated fat content (palmitic acid, stearic acid), which has been shown to raise LDL cholesterol, which in turn increases risk of cardiovascular disease. In addition to discussing evidence and mechanisms related to fish and meat intake and cardiovascular disease, this chapter also discusses concerns regarding mercury contamination related to fish consumption and cardiovascular disease.