Effect of fish oil on blood pressure and serum lipids in hypertension and hyperlipidaemia.

: We studied the antihypertensive and hypolipidaemic effects of fish oil containing eico-sapentaenoic acid and docosahexaenoic acid in a capsule preparation in patients with mild to moderate essential hypertension and in patients with hypercholesterolaemia. In addition, we used two independent procedures to analyse changes in blood pressure, casual and self-recorded blood pressure measurements. A very moderate blood pressure lowering effect of fish oil was confirmed in this study, and a slight antihyperlipidaemic effect in plasma triglycerides was demonstrated. During the fish oil treatment, casual blood pressure values were consistently lower than self-recorded values. It is assumed that this was an observer error due to knowledge of the treatment.