Effect of palm oil on lipid and lipoprotein metabolism and eicosanoid production in rats.

Palm oil (PA), which is very rich in palmitic acid, influenced the serum cholesterol concentration and tissue eicosanoid profile of rats characteristically. It increased the serum cholesterol concentration compared with safflower oil (SA), but the degree of the elevation was moderate compared with that of olive oil (OL). The proportion of arachidonic acid in tissue lipids was by no means lower on a PA diet than on an SA diet. The ratio of prostacyclin produced by the aorta to thromboxane A2 in plasma was not simply predicted by the dietary level of saturated fatty acid. PA tended to facilitate the utilization of arachidonate for prostacyclin in vitro in peritoneal macrophages compared with SA. Fatty acid profiles of PA rather than the glyceride structure or the tocotrienol appeared to be the major determinant for the specific features of lipid metabolism observed in rats fed PA.