EFFECT OF MODIFIED DAIRY FAT ON POSTPRANDIAL AND FASTING PLASMA-LIPIDS AND LIPOPROTEINS IN HEALTHY-YOUNG MEN

Fatty acid profile of milk fat can be modified by cow feeding strategi es. Our aim was postprandially and after 4 wk to compare the effect of a modified milk fat (M diet) [with 16% of the cholesterolemic saturat ed fatty acid (C12-16) replaced by mainly oleic and stearic acids] wit h the effect of D diet, including a conventional Danish milk fat on pl asma lipids and lipoproteins. A side effect of the cow feeding regime was a 5% (w/w) increase in trans fatty acid in M diet. Eighteen subjec ts were fed for two periods of 4 wk strictly controlled isoenergetic t est diets with 40% of energy from total fat and the same content of di etary cholesterol in a randomized study with cross-over design. Contra ry to expectations, fasting low density lipoprotein (LDL) cholesterol concentration did not differ after the experimental periods. However, M diet resulted in a higher fasting total triacylglycerol concentratio n compared to D diet (P = 0.009). Postprandial samples were taken at t wo different occasions (i) at day 21, after breakfast and lunch and (i i) on the last day of the study 2, 4, 6, and 8 h after a fat load. Pos tprandial plasma triacylglycerol and chylomicron triacylglycerol showe d higher peak Values after D diet than M diet (interaction effect, die t x times P < 0.05). In conclusion, M diet did not lower LDL cholester ol compared to D diet. Thus any cholesterol-lowering effect of oleic a nd stearic acids may have been obscured by the high content of cholest erol-raising saturated fatty acids in mi Ik fat. A higher content of t he trans fatty acids in M diet might have counteracted the cholesterol neutral/decreasing effect and increased plasma triacylglycerol.