Blood Pressure Modulating Properties of Omega-3 Polyunsaturated Fatty Acids (PUFA)

Abstract

Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) from fish and fish oils appear to protect against coronary heart disease: their dietary intake is in fact inversely associated to cardiovascular disease morbidity/mortality in population studies. Recent evidence suggests that at least a part of their heart protective effect is mediated by a relatively small but significant decrease in blood pressure level. In fact, ω-3 PUFAs exhibit wide-ranging biological actions that include regulating both vasomotor tone and renal sodium excretion, partly competing with ω-6 PUFAs for common metabolic enzymes and thereby decreasing the production of vasoconstriction rather than vasodilating and anti-inflammatory eicosanoids. PUFAs also reduce angiotensin-converting enzyme activity, angiotensin II formation and tumour growth factor-β expression, enhance endothelial nitric oxide generation and activate the parasympathetic nervous system. The final results are an improved vasodilation and arterial compliance of both small and large arteries. Preliminary clinical trials involving patients with dyslipidaemia, patients with diabetes mellitus and elderly subjects, as well as normotensive and hypertensive subjects, confirm this working hypothesis: two meta-analyses suggest that PUFA are able to slightly, but significantly improve arterial hypertension. Future research will clarify whether PUFA supplementation could improve the antihypertensive action of specific blood-pressure-lowering drug classes and of statins.