British Journal of Nutrition

Research Article

Microalgal docosahexaenoic acid decreases plasma triacylglycerol in normolipidaemic vegetarians: a randomised trial

Julia Gepperta1, Veronika Krafta1, Hans Demmelmaira1 and Berthold Koletzkoa1 c1

a1 Division of Metabolic Diseases and Nutrition, DR. von Hauner Children's Hospital, Ludwig Maximilians University of Munich, Lindwurmstraβe 4, D-80337 Munich, Germany

Abstract

Triacylglycerol (TG) lowering effects of n−3 long-chain PUFA (n−3 LCPUFA) have been repeatedly demonstrated, but studies investigating the individual effects of EPA or DHA on plasma TG and lipoproteins in man are rare. The effects of a new DHA-rich, almost EPA-free microalgae oil (Ulkenia sp.) on plasma lipids and several safety parameters were investigated in a double-blind, placebo-controlled, parallel design intervention study. Normolipidaemic vegetarians (eighty-seven females, twenty-seven males) consumed daily microalgae oil (0·94g DHA/d) or olive oil (as placebo) for 8 weeks. DHA supplementation decreased plasma TG by 23% from 1·08 (sem 0·07) to 0·83 (sem 0·04) mmol/l (p<0·001). Absolute TG decreases after DHA supplementation were inversely correlated to baseline TG concentrations (r −0·627, p<0·001). Plasma total, LDL and HDL cholesterol increased significantly in the DHA group, resulting in lower TG:HDL cholesterol and unchanged LDL:HDL and total cholesterol:HDL cholesterol ratios. The intake of DHA-rich microalgae oil did not result in any physiologically relevant changes of safety and haemostatic factors. In conclusion, DHA-rich oil from microalgae Ulkenia sp. was well tolerated and can be considered a suitable vegetarian source of n−3 LCPUFA. Although DHA supplementation improved some CHD risk factors (plasma TG, TG:HDL cholesterol ratio), LDL cholesterol increased. Therefore, the overall effects of this intervention on CHD risk deserve further investigation.

(Received April 19 2005)

(Revised November 11 2005)

(Accepted December 06 2005)

Correspondence:

c1 *Corresponding author: Professor Berthold Koletzko, fax +49 89 5160 3336, email Berthold.Koletzko@med.uni-muenchen.de