Metabolic Basis for the Cholesterol-Lowering Action of Dietary Polyunsaturated Fatty Acids

The plasma level of triacylglycerols in horses fed high-fat diets containing either soybean oil or palm oil

The influence of dietary soybean oil versus palm oil on the plasma level of triacylglycerols was determined in a crossover experiment with four horses. Based on published data for humans and laboratory animals it was expected that a diet rich in unsaturated fatty acids in the form of soybean oil compared to saturated fatty acids in the form of palm oil would lower the plasma triacylglycerol level. The feeding of soybean oil versus palm oil for a period of four weeks did not change the level of plasma triacylglycerols in horses. Mean levels of triacylglycerol, free fatty acids and 3-hydroxybutyrate were 0.17 (SE, 0.04), 0.44 (SE, 0.063) and 0.16 (SE, 0.008) mmol/l, respectively. The fatty acid composition of the plasma triacylglycerols reflected the fatty acid composition of the diets. The activity of lipoprotein lipase was not different between the treatments. It is concluded that, under the present experimental conditions, the feeding of soybean oil to horses does not affect triacylglycerol secretion into plasma and thus does not influence the concentration of plasma triacylgycerols, when compared to the feeding of palm oil.