Replacement of dietary fat with palm oil: effect on human serum lipids, lipoproteins and apolipoproteins

Thirty-eight male volunteers participated in a double-blind cross-over trial evaluating the effect of replacing the usual sources of saturated fat in the Dutch diet (animal fats and hydrogenated oils) by palm oil, which is virtually free of cholesterol andtrans-fatty acids, on serum lipids, lipoproteins and apolipoproteins. Maximum (about 70%) replacement had no significant effect on serum total cholesterol or most lipoprotein fractions, but resulted in an 11% increase in serum high-density-lipoprotein (HDL)2-cholesterol relative to the control (P2= 0.01). The palm-oil diet also caused an 8% decrease in low-density-lipoprotein (LDL):HDL2+HDL3-cholesterol ratio (P2= 0.02) as well as a 9% decrease in triacylglycerols in the low-density-lipoprotein fractions (P2= 0.01). Palm oil consumption resulted in a 4% increase in serum apolipoprotein AI (P2= 0.008) and a 4% decrease in apolipoprotein B (P2= 0.01) relative to the control diet; the B:AI apolipoprotein ratio was decreased by 8% (P2< 0.0001). These results were not significantly affected by the different lipoprotein E phenotypes of the volunteers. Although the observed differences were relatively modest, the present study, nonetheless, indicates that dietary palm oil, when replacing a major part of the normal fat content in a Dutch diet, may slightly reduce the lipoprotein- and apolipoprotein-associated cardiovascular risk profiles