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This Article Full Text (Publish Ahead of Print[PDF]) All Versions of this Article: 91/1/32    most recent ajcn.2009.28070v1 Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Racette, S. B Articles by Ostlund, R. E PubMed PubMed Citation Articles by Racette, S. B Articles by Ostlund, R. E, Jr Agricola Articles by Racette, S. B Articles by Ostlund, R. E

Dose effects of dietary phytosterols on cholesterol metabolism: a controlled feeding study^1,2,3

¹ From the Washington University School of Medicine, St Louis, MO (SBR, XL, CAS, LM, and REO), and the Pennington Biomedical Research Center, Baton Rouge, LA (ML and MMM).

² Supported by NIH grant R01 HL050420-12 (to REO), the Washington University General Clinical Research Center (grant MO1 RR-00036), the Washington University Mass Spectrometry Resource (grant RR-00954), the Diabetes Research and Training Center (grant P60-DK020579-30), and the Washington University Clinical Nutrition Research Unit (grant P30 DK056341).

³ Address correspondence to SB Racette, Washington University School of Medicine, Campus Box 8502 4444, Forest Park Avenue, St Louis, MO 63108. E-mail: racettes{at}wustl.edu.

ABSTRACT

Background: Phytosterol supplementation of 2 g/d is recommended by the National Cholesterol Education Program to reduce LDL cholesterol. However, the effects of different intakes of phytosterol on cholesterol metabolism are uncertain.

Objective: We evaluated the effects of 3 phytosterol intakes on whole-body cholesterol metabolism.

Design: In this placebo-controlled, crossover feeding trial, 18 adults received a phytosterol-deficient diet (50 mg phytosterols/2000 kcal) plus beverages supplemented with 0, 400, or 2000 mg phytosterols/d for 4 wk each, in random order. All meals were prepared in a metabolic kitchen; breakfast and dinner on weekdays were eaten on site. Primary outcomes were fecal cholesterol excretion and intestinal cholesterol absorption measured with stable-isotope tracers and serum lipoprotein concentrations.

Results: Phytosterol intakes (diet plus supplements) averaged 59, 459, and 2059 mg/d during the 3 diet periods. Relative to the 59-mg diet, the 459- and 2059-mg phytosterol intakes significantly (P < 0.01) increased total fecal cholesterol excretion (36 ± 6% and 74 ± 10%, respectively) and biliary cholesterol excretion (38 ± 7% and 77 ± 12%, respectively) and reduced percentage intestinal cholesterol absorption (–10 ± 1% and –25 ± 3%, respectively). Serum LDL cholesterol declined significantly only with the highest phytosterol dose (–8.9 ± 2.3%); a trend was observed with the 459-mg/d dose (–5.0 ± 2.1%; P = 0.077).

Conclusions: Dietary phytosterols in moderate and high doses favorably alter whole-body cholesterol metabolism in a dose-dependent manner. A moderate phytosterol intake (459 mg/d) can be obtained in a healthy diet without supplementation. This trial was registered at clinicaltrials.gov as NCT00860054.

Received for publication May 14, 2009. Accepted for publication October 9, 2009.