Phytosterols, phytostanols and their esters: from natural to functional foods

Phytosterols, phytostanols and their esters are a group of steroid alcohols that occur naturally in plants. As natural constituents of plant structures, phytosterols contribute to the regulation of the fluidity and permeability of cell membranes. They are found mostly in vegetable oils, fruits, nuts, cereals and legumes. Themost abundant phytosterols are beta-sitosterol, campesterol and stigmasterol. During the last 15 years the market for phytosterols, as dietary supplements, has lead to a rapidly growingworldwidemarket for functional foods containing phytosterols and stanols. Even though many different clinical trials have clearly demonstrated that phytosterols reduce LDL-cholesterol, it is unclear whether phytosterols have a positive effect on cardiovascular disease. Until now, there are no data related to the effect of phytosterol consumption on the development of cardiovascular diseases. This review focuses on the biochemistry of phytosterols, their metabolism and role in health and in pathological conditions.