Addition of blended phytosterols to a prudent North American diet improved plasma LDL-cholesterol concentrations by mechanisms that did not result in significant changes in endogenous cholesterol synthesis in hypercholesterolemic men.

These data indicate that, in their free unesterified form, sterols and stanols lower plasma LDL cholesterol equivalently in hypercholesterolemic persons by suppressing cholesterol absorption.

Dietary phytosterols have been shown to reduce plasma cholesterol concentrations when consumed in different food matrices, but their effectiveness in nonfat or low-fat beverages has not been established. The objective of this study was to examine whether phytosterols alter plasma lipid levels when incorporated into nonfat or low-fat beverages. Fifteen moderately hypercholesterolemic men and women consumed three precisely controlled diets for periods of 21 days each in random order. Diets contained either a nonfat placebo beverage (NF), a beverage that is nonfat with added phytosterols (NFPS), or a beverage that is low in fat with added phytosterols (LFPS). Total cholesterol concentrations were not different between groups at endpoint, decreasing ( P Ͻ 0.05) equally by 8.5%, 11.6%, and 10.1% with NF, NFPS, and LFPS consumption, respectively. There was no effect of dietary treatment on LDL cholesterol concentrations, which decreased over time ( P Ͻ 0.05) by 5%, 10.4%, and 8.5% with NF, NFPS, and LFPS, respectively. HDL cholesterol and triacylglycerol concentrations were unaffected by the diets. Provision of phytosterols as part of nonfat and low-fat beverages did not exert any greater hypocholesterolemic effect than a nonfat placebo beverage. These results show that intake of phytosterols in a low-fat beverage format is not efficacious for lipid level modification. Low-fat diets containing less than 30% of energy as fat and less than 10% as saturated fat have long been promoted for lowering plasma cholesterol concentrations in hypercholesterolemic patients. Recently, the National Cholesterol Education Program Adult Treatment Panel III guidelines have added the inclusion of phytosterols as part of their therapeutic lifestyle changes dietary guidelines (1) in addition to the traditional recommendations to lower total fat, saturated fat, and cholesterol intakes.Furthermore, in 2000, the US Food and Drug Administration issued a health claim stating that foods containing plant sterol and stanol esters, when consumed in foods low in saturated fat and cholesterol, reduced the risk of coronary heart disease (2). Phytosterols have traditionally been incorporated into margarines, spreads, and other high-fat foods and have been shown to be efficacious in lowering total cholesterol (TC) and LDL cholesterol (3)(4)(5)(6)(7)(8)(9)(10)(11). In a recent meta-analysis, it was reported that consumption of more than 2 g of phytosterols/day reduced LDL cholesterol concentrations by 0.33 to 0.54 mmol/l, depending on the age of the subjects studied, and that intakes of less than 2 g/day led to reductions in LDL cholesterol of at least 0.4 to 0.5 mmol/l (3). It is thus generally agreed that phytosterol consumption leads to, on average, a 10% reduction in TC and a 13% reduction in LDL cholesterol concentrations.Phytosterols exert their cholesterol-lowering action by suppressing intestinal cholesterol absorption while partially suppressing cholesterol biosynthesis (9, 12, 13). While they are only partially absorbed into the circul...

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It has been suggested that phytosterol and phytostanol esters possess similar cholesterol-lowering properties, however, whether mechanisms responsible are identical has not been addressed. To address this question, cholesterol plasma levels, absorption, biosynthesis, and turnover were measured in 15 hypercholesterolemic subjects consuming prepared diets each over 21 d using a crossover design. Diets contained either i ) margarine (M), ii ) margarine with phytosterol esters (MSE) (1.84 g/d), or iii ) margarine with phytostanol esters (MSA) (1.84 g/d). Cholesterol absorption was measured using the ratio of [ 13 C]cholesterol oral :D 7 -cholesterol IV ; biosynthesis using D incorporation from D 2 O and turnover by D 7 -cholesterol IV decay rates. Plasma total cholesterol level at d 21/22 was lower ( P Ͻ 0.05) for MSE (13.4%) but not MSA (10.2%) versus M (6.0%) diets. Plasma low density lipoprotein-cholesterol (LDL-C) mean reductions at d 21/22 were larger ( P Ͻ 0.05) for MSE (12.9%) and MSA (7.9%) compared with M (3.9%). Plasma TG and high density lipoprotein-cholesterol (HDL-C) levels did not differ across diets. Cholesterol absorption was reduced ( P Ͻ 0.05) 36.2 and 25.9% at d 21 for MSE and MSA versus M, while cholesterol biosynthesis was reciprocally increased ( P Ͻ 0.05) 53.3 and 37.8% for MSE and MSA versus M, respectively. Cholesterol turnover was not influenced by diet. These data indicate that plant sterol and stanol esters differentially lower circulating total and LDL cholesterol levels by suppression of cholesterol absorption in hypercholesterolemic subjects. -