Clinical studies on lipid and blood pressure lowering effect of eicosa-pentaenoic acid-rich diet.

15 volunteers were put on a mackerel (MD) and herring diet (HD) for 2 weeks in a cross-over design. At the end of the dietary periods eicosa-pentaenoic acid (EPA) was predominantly incorporated into cholesterol esters (CE), whereas docosahexaenoic acid (DHA) appeared more in triglycerides (TG). This was more pronounced after MD as compared to HD. After MD a significant decrease of serum TG, total cholesterol (C) and lecithin cholesterol acyl transferase (LCAT) activity could be observed returning to the initial levels 3 months later. After HD only a decrease of LCAT was significant. In addition, a marked decrease in blood pressure (BP) was associated with lower plasma noradrenaline levels after MD, but not after HD. In 14 patients with mild essential hypertension an enhanced percentage of EPA and DHA in the lipids of VLDL, LDL and HDL could be confirmed. After MD serum TG, C, LDL-C and LCAT were significantly decreased, whereas HDL-C appeared increased. After HD the changes were of minor degree. Systolic BP was significantly lower at the end of MD. In 8 patients with type IV and V hyperlipoproteinemia (HLP) similar changes could be seen, the most striking finding being a fall in serum TG, especially if initial values were extraordinarily high. The data suggest a beneficial effect of MD on several parameters known as risk factors of atherosclerosis.