[Hemodynamic effect of unsaturated fatty acids. Do fish oils have an antihypertensive effect?]

While there is still uncertainty about a possible blood pressure lowering effect of omega-6 fatty acids (vegetable oil) in man, a number of reports have described cardiovascular effects of an increased intake of omega-3 fatty acids (fish oil). In normotensive volunteers, unchanged or mildly decreased arterial blood pressure, a decrease in the response to exogenous vasopressors, especially noradrenaline, a rise in renal blood flow, and increased sensitivity of the arterial baroreflex system have been reported. In all studies involving patients with essential hypertension reported to date, omega-3 fatty acids have been shown to decrease arterial blood pressure. So far little is known about the dose-response relationship of this blood pressure-lowering effect. In the short-term studies available to date doses of more than 5 g/day of omega-3 fatty acids were necessary to effectively lower blood pressure. At present, the mechanism of the cardiovascular effects of fish oil is also unknown.