THE POSITIONAL DISTRIBUTION OF FATTY-ACIDS IN PALM OIL AND LARD INFLUENCES THEIR BIOLOGIC EFFECTS IN RATS

Dietary fatty acids in the sn-2 position are preferentially absorbed a s monoacylglycerols. To determine whether they also have more importan t biologic effects, rats were fed for 2 and 4 mo a purified diet conta ining native palm oil, interesterified palm oil, native lard or intere sterified lard. Interesterification that increased or decreased the le vel of fatty acids in position 2 depending on the fat, resulted in sig nificant corresponding changes in the fecal excretion of saturated fat ty acids. Fecal excretion of saturated fatty acids was associated with significant changes in some plasma fatty acids. Interesterification i n lard resulted in significantly lower plasma triglycerides, and in pa lm oil, increased platelet aggregation induced by ADP. Lipemia, platel et aggregation and associated plasma fatty acids (palmitic, heneicosan oic and docosahexaenoic acids) were significantly affected only by die tary fatty acids at the sn-2 position. Even without changes in absorpt ion, only linoleic acid in position 2 was correlated with the plasma c oncentration of the corresponding longer chain arachidonic acid. These results in rats confirm that the fatty acids (saturated and unsaturat ed) in position 2 of dietary triglycerides play a crucial role in the metabolism and biologic effects of these fatty acids.