Scientists know that plant sterols interfere with cholesterol absorption, but how well do these compounds work to lower cholesterol? To answer this question, investigators fed volunteers a carefully controlled diet with a measured small amount of plant sterols. They were then given a daily beverage with either no, 400 mg or 2000 mg of plant sterols as a supplement. At the highest dose, blood cholesterol levels dropped significantly by almost 9 percent. At the lower level of phytosterol supplementation, there was only a non-significant trend toward lower LDL cholesterol. This lower level can be achieved in the diet without supplementation, however.
[American Journal of Clinical Nutrition, Dec 2009]