The beneficial effects of plant sterols on serum cholesterol.

Phytosterol-enriched margarines are a recent addition to the list of so-called 'functional foods'. The ingestion of phyto-sterols lowers the serum cholesterol by inhibiting intestinal uptake of the sterol. The phytosterols available in consumer products are comprised predominantly of beta-sitosterol and sitostanol. The esterified form of these phytosterols increases their solubility and enhances their residence time in the small intestine. Their ability to displace cholesterol from micelles in the small intestine underlies the mechanism that inhibits cholesterol absorption, leading to a 10% reduction in total serum cholesterol. Numerous well designed studies have documented the beneficial actions of these phytosterols on serum cholesterol.