Part II: Benefits for Prevention of Adult Chronic Disease
Most evidence for benefits of seafood consumption and EPA/DHA supplementation associated with coronary heart disease (CHD) mortality is inferred from interventional studies of populations at risk, observational studies in the general population, and mechanistic studies. Early investigations of the association between diet and cardiovascular disease led to the recommendations to restrict dietary fat and cholesterol as a public health intervention to prevent CHD. However, subsequent observations suggest a more complex association between dietary fat intake and cardiovascular pathophysiology (Howard et al., 2006).
Certain populations in the Mediterranean region consuming a diet relatively high in monounsaturated fat from olive oil enjoyed some of the lowest cardiovascular disease rates in the world. Another intriguing observation came from the comparison of Greenland Eskimo populations that had low mortality rates from CHD compared to the mainland Danish population, despite having a diet rich in fat (Bang et al., 1971). Bang et al. (1971) hypothesized that genetics, lifestyle, and the high content of EPA/DHA in the diet (which consisted primarily of fish, sea birds, seal, and whale) may account for the low cardiovascular mortality rate observed in this population. Plasma lipid patterns examined in this study showed that most types of lipids were decreased compared to a Danish cohort control and Eskimos living in Denmark (p<0.001). Remarkably, the levels of pre-β lipoprotein (p<0.001) and, consequently, plasma triglycerides (p<0.001) were much lower among the Greenland Eskimos than the Danish controls. As a result of this and related studies, seafood consumption, including or even especially of seafood rich in fat, has received increased attention as a public health means to decrease the burden of cardiovascular disease.
Several observational studies have shown an inverse association between seafood consumption and the risk of cardiovascular disease, most probably due to reductions of sudden death (reviewed in Wang et al., 2006). Some studies, however, have not found a significant association between seafood consumption and cardiovascular disease. These discrepancies may be due to