Impact of omega-3 polyunsaturated fatty acids on vascular function and blood pressure: relevance for cardiovascular outcomes

Aims: To overview the effects of omega-3 polyunsaturated fatty acids (PUFA) on blood vessels and blood pressure and their relevance for cardiovascular prevention. Data synthesis: The importance of omega-3 PUFA for the cardiovascular system has come under the spotlight during the last decades. These fatty acids are present in variable amounts in cell membranes of mammal species and their content affects a variety of cellular functions. Evidence obtained in animal and human studies suggest that omega-3 PUFA affect many steps of the atherosclerotic process. In blood vessels, omega-3 PUFA improve endothelial function, promote vasodilatation via relaxation of smooth muscle cells, exert antioxidant, antiinflammatory, and antithrombotic actions, delay development of plaques and increase their stability, and decrease wall stiffening. Omega-3 PUFA might affect blood pressure and studies conducted with ambulatory monitoring suggest that supplementation with these fatty acids decreases average 24-hour levels. This effect on blood pressure is related with pretreatment membrane content of omega-3 PUFA and this might explain some inconsistencies among intervention trials. Meta-analyses indicate that omega-3 PUFA have a mild but significant blood pressure lowering effect. While encouraging results were initially obtained with use of omega-3 PUFA supplements in secondary prevention trials, meta-analyses have not confirmed the ability of these fatty acids to decrease the risk of coronary heart and cerebrovascular disease. Conclusions: Omega-3 PUFA are associated with significant improvement of vascular function and lowering of blood pressure. However, the evidence currently supporting a role of these fatty acids in cardiovascular prevention is weak and needs further investigation.