Low-fat and high-monounsaturated fatty acid diets decrease plasma cholesterol ester transfer protein concentrations in young, healthy, normolipemic men

Background: Cholesterol eater transfer protein (CETP) mediates the transfer of cholesteryl esters from HDL to apolipoprotein (apo) B-containing lipopr oteins. The possible atherogenic role of this protein is controversial. Die t may influence plasma CETP concentrations. Objective: The objective was to determine whether the changes in plasma lip ids observed after consumption of 2 lipid-lowering diets are associated wit h changes in plasma CETP concentrations. Design: We studied 41 healthy, normolipidemic men over 3 consecutive 4-wk d ietary periods: a saturated fatty acid-rich diet (SFA diet: 38% fat. 20% sa turated fat), a National Cholesterol Education Program Step I diet (NCEP St ep I diet: 28% fat, 108 saturated fat), and a monounsaturated fatty acid-ri ch diet (MUFA diet: 38% fat, 22% monounsaturated fat). Cholesterol content (27.5 mg/MJ) was kept constant during the 3 periods. Plasma concentrations of total, LDL, and HDL cholesterol; triacylglycerol; apo A-I and B; and CET P were measured at the end of each dietary period. Results: Compared with the SFA diet, both lipid-lowering diets significantl y decreased plasma total and LDL cholesterol, apo B, and CETP. Only the NCE P Step I diet lowered plasma HDL cholesterol. Positive. significant correla tions were found between plasma CETP and total (r = 0.3868, P < 0.0001) and LDL (r = 0.4454, P < 0.0001) cholesterol and also between changes in CETP concentrations and those of total (r = 0.4543. P < 0.0001) and LDL (r = 0.4 554, P < 0.0001) cholesterol. Conclusions: The isoenergetic substitution of a high-saturated fatty acid d iet with an NCEP Step I or a high-monounsaturated fatty acid diet decreases plasma CETP concentrations.