The influence of different ratios and dosages of an omega 6:omega 3 fatty acid supplement on the lipoprotein cholesterol and fatty acid profile in nonhuman primates on a western atherogenic diet

Vervet monkeys consuming an atherogenic diet were supplemented with either 200 or 800 mg/d of each of four different gamma-linolenic acid:eicosapentaenoic acid ratios (9:1, 4:1, 2:1, and 1:1) for 12 weeks. Plasma and lipoprotein lipids, and low density lipoprotein (LDL) fatty acid analyses were done before and after supplementation. The 4:1 omega 6:omega 3 fatty acid supplement at 200 mg/d elicited the most favourable plasma lipoprotein cholesterol response. The cholesterol concentration in LDL and high density lipoprotein was respectively decreased and increased. Linoleic and arachidonic acid content in the LDL cholesteryl ester remained constant. Dihomo-gamma-linolenic and eicosapentaenoic acid were increased in LDL phosphatidylcholine, while the arachidonic acid content remained relatively constant. It is concluded that the 4:1 ratio at 200 mg/d was the optimum supplement in our model. The long-term effect of this supplement on lipoprotein metabolism and atherosclerosis needs to be investigated. (C) 1997 Elsevier Science Inc.