BACKGROUND: Phytosterols are naturally occurring plant compounds found in vegetables and legumes. They have a chemical structure similar to cholesterol, but inhibit the absorption of cholesterol in the intestine. Many studies have found that esterified phytosterols added to margarine can lower blood levels of cholesterol.
RESEARCH: In this study, researchers asked 15 people with elevated cholesterol levels to eat four different dietary treatments, each for a 21- day period. Dietary treatments included 1.8 g per day of unesterified plant sterols, hydrogenated sterols (stanols), a 50:50 mix of sterols and stanols, and corn starch (as a placebo) mixed into butter. The total diet composition was precisely defined and provided to all subjects throughout the study.
RESULTS: Sterols reduced cholesterol absorption by 56 percent, compared with 34.4 percent and 48.9 percent for stanols and the 50:50 combination of sterols and stanols, respectively. The placebo had no significant effect. As compared to the placebo, total blood cholesterol levels declined by 7.8 percent, 11.9 percent, and 13.1 percent and low-density lipoprotein (LDL) cholesterol levels decreased by 11.3 percent, 13.4 percent, and 16 percent, respectively, when the subjects consumed sterols, stanols, and the combination. The reductions in total and LDL cholesterol levels were not statistically significantly different among sterol treatments.
IMPLICATIONS: This study found that unesterified plant sterols and stanols equivalently reduced blood levels of total and LDL cholesterol, but that the sterols were most effective in suppressing cholesterol absorption.
Vanstone CA, Raeini-Sarjaz M, Parsons WE, et al, "Unesterified plant sterols and stanols lower LDL-cholesterol concentrations equivalently in hypercholesterolemic persons," American Journal of Clinical Nutrition, 2002;76:1272-1278.
For the original abstract, visit: http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12450893&dopt=Abstract