Dietary fats, fish, and blood pressure

In humans any effects of dietary saturated fats or omega-6 polyunsaturates on blood pressure appear to be mediated by changes in caloric intake and long-term weight changes. In contrast, omega-3 fatty acids have a mild antihypertensive effect which is seen most clearly in untreated subjects with higher blood pressures, in older people, and during sodium restriction. The mechanism may be due to a combination of effects consequent to incorporation of omega-3 fatty acids into vascular phospholipids, leading to reduced formation of endothelial contractile substances in larger vessels and impairment of sympathetic neuroeffector and other vasoconstrictor mechanisms in resistance vessels.