Journal Article

The effects of phytosterols present in natural food matrices on cholesterol metabolism and LDL-cholesterol: a controlled feeding trial

Lefevre, M, Most, M, Racette, S B, Lin, X, Spearie, C A, Ma, L, Ostlund, R E

2010

Overview

Background/Objectives: Extrinsic phytosterols supplemented to the diet reduce intestinal cholesterol absorption and plasma low-density lipoprotein (LDL)-cholesterol. However, little is known about their effects on cholesterol metabolism when given in native, unpurified form and in amounts achievable in the diet. The objective of this investigation was to test the hypothesis that intrinsic phytosterols present in unmodified foods alter whole-body cholesterol metabolism. Subjects/Methods: In all, 20 out of 24 subjects completed a randomized, crossover feeding trial wherein all meals were provided by a metabolic kitchen. Each subject consumed two diets for 4 weeks each. The diets differed in phytosterol content (phytosterol-poor diet, 126 mg phytosterols/2000 kcal; phytosterol-abundant diet, 449 mg phytosterols/2000 kcal), but were otherwise matched for nutrient content. Cholesterol absorption and excretion were determined by gas chromatography/mass spectrometry after oral administration of stable isotopic tracers. Results: The phytosterol-abundant diet resulted in lower cholesterol absorption (54.2±2.2% (95% confidence interval 50.5%, 57.9%) vs 73.2±1.3% (69.5%, 76.9%), P <0.0001) and 79% higher fecal cholesterol excretion (1322±112 (1083.2, 1483.3) vs 739±97 mg/day (530.1, 930.2), P <0.0001) relative to the phytosterol-poor diet. Plasma lathosterol/cholesterol ratio rose by 82% (from 0.71±0.11 (0.41, 0.96) to 1.29±0.14 μg/mg (0.98, 1.53), P <0.0001). LDL-cholesterol was similar between diets. Conclusions: Intrinsic phytosterols at levels present in a healthy diet are biologically active and have large effects on whole-body cholesterol metabolism not reflected in circulating LDL. More work is needed to assess the effects of phytosterol-mediated fecal cholesterol excretion on coronary heart disease risk in humans.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 631/443/319 / 692/700/459/1994 / Absorption / adults / Anticholesteremic Agents - metabolism / Anticholesteremic Agents - pharmacology / Biological activity / Biological and medical sciences / Cardiovascular disease / Cardiovascular diseases / Cholesterol / Cholesterol - blood / Cholesterol - metabolism / Cholesterol, LDL - blood / Cholesterol, LDL - metabolism / Clinical Nutrition / Clinical trials / Confidence intervals / Coronary artery disease / Coronary heart disease / Cross-Over Studies / Diet / Diets / Epidemiology / Excretion / experimental diets / Fecal coliforms / feeding / Feeding trials / Feeding. Feeding behavior / Female / Food / food composition / Fundamental and applied biological sciences. Psychology / Gas chromatography / Health risks / Heart diseases / human nutrition / Humans / Internal Medicine / intestinal absorption / Intestine / Isotopic tracers / Kitchens / Lipid metabolism / Lipoproteins / Lipoproteins (low density) / Low density lipoprotein / Male / Mass spectrometry / Mass spectroscopy / Meals / Medical sciences / Medicine / Medicine & Public Health / Metabolic Diseases / Metabolism / Middle Aged / Natural & organic foods / Nutrient content / Oral administration / original-article / Phytosterols / Phytosterols - metabolism / Phytosterols - pharmacology / Public Health / randomized clinical trials / Tracers / Vertebrates: anatomy and physiology, studies on body, several organs or systems