Reduction of blood pressure associated with dietary polyunsaturated fat.

Evidence linking the beneficial effect of dietary polyunsaturated fat on systolic and distolic blood pressure is reported. Under controlled dietary conditions, i.e., when the polyunsaturated fat to saturate fat ratio (P/S) is maintained at about 1.0, with fat providing 25% of total energy intake, blood pressure is significantly lowered in healthy males and females in the 40- to 60-year age group. The subjects selected for these studies were either normotensive or mildly hypertensive. When the subjects resumed their usual diets, their blood pressures reverted to baseline values. Body weights of the subjects remained relatively constant in these studies, and sodium chloride intakes averaged 8 to 12 g per day. It is suggested that the lowering of blood pressure by dietary linoleic acid is mediated through prostaglandins.