Impact of adding MUFA to a portfolio diet on in vivo kinetics of apo AI, B100 and B48 in subjects with hypercholesterolemia

This randomized parallel study assessed the impact of adding monounsaturated fatty acids (MUFA) to a dietary portfolio of cholesterol lowering foods on the metabolism of apoAI, VLDL apoB100 and apoB48 in subjects with hypercholesterolemia. Sixteen men and postmenopausal women consumed a run‐in stabilization diet designed according to the National Cholesterol Education Program (NCEP) guidelines for 4 weeks. Subjects were then randomly assigned to an experimental portfolio diet either high or low in MUFA for another 4 weeks. MUFA substituted 13.0% of total calories from carbohydrate in the high‐MUFA portfolio. The high‐MUFA portfolio diet resulted in higher plasma HDL‐cholesterol (C) concentrations and apoAI pool size (PS) compared with the low‐MUFA portfolio diet (+12.5% and +6.1% difference respectively, P ≤ 0.03). The increase in HDL and apoAI with the high MUFA diet was mainly attributable to a reduction in apoAI fractional catabolic rate (FCR, −12.6%, P = 0.02), with no significant change in production rate (PR). There were no between or within‐treatment differences in VLDL apoB100 and apoB48 FCR, PR and PS (all P > 0.08). These data suggest that adding MUFA to a cholesterol‐lowering diet provides an added advantage of raising HDL‐C, primarily through a reduction in HDL clearance rate. Financial support: CIHR, Canada Research Chair Program and Loblaws.