REVIEW Phytosterols, phytostanols and their esters: from natural to functional foods T. Bacchetti • S. Masciangelo • V. Bicchiega • E. Bertoli • Gianna Ferretti Received: 14 April 2010 / Accepted: 18 December 2010 / Published online: 20 January 2011 Ó Springer-Verlag 2011 Abstract Phytosterols, phytostanols and their esters are a group of steroid alcohols that occur naturally in plants. As natural constituents of plant structures, phytosterols contrib- ute to the regulation of the fluidity and permeability of cell membranes. They are found mostly in vegetable oils, fruits, nuts, cereals and legumes. The most abundant phytosterols are b-sitosterol, campesterol and stigmasterol. During the last 15 years the market for phytosterols, as dietary supplements, has lead to a rapidly growing worldwide market for functional foods containing phytosterols and stanols. Even though many different clinical trials have clearly demonstrated that phy- tosterols reduce LDL-cholesterol, it is unclear whether phy- tosterols 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. Keywords Phytosterols Á Phytostanols Á Functional foods Introduction Phytosterols, phytostanols and their esters are a group of steroid alcohols that are natural constituents of plant cell membrane and contribute to the regulation of the fluidity and permeability of cell membranes [1]. They are substrates for the synthesis of numerous secondary plant metabolites and act as biogenic precursors of compounds involved in growth. More than 200 different types of phytosterols have been reported in plant species. The chemical structure of phytos- terols differs from that of cholesterol only by minor modi- fications (Fig. 1). b-Sitosterol, campesterol and stigmasterol (Fig. 1) are the most frequent plant sterols in food and rep- resent about in media 65, 30 and 3% of dietary intake [2]. Plant stanols, on the other hand, are the saturated form of plant sterols, meaning they have no double bond in the sterol ring. Saturation of b-sitosterol, campesterol or stigmasterol gives rise to sitostanol, campestanol or stigmastanol, respec- tively. In addition to the free form, phytosterols occur as four types of conjugates, in which the 3 -OH group is esterified to a fatty acid or a hydroxycinnamic acid, or glycosylated with a hexose (usually glucose) or a 6-fatty-acyl hexose (Fig. 2)[1]. During the last 15 years the market for phytosterols as dietary supplements, has led to a rapidly growing worldwide market 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 [3]. Until now, there are no data related to the effect of phytosterol consumption on the development of cardiovascular diseases [4]. This review focuses on the biochemistry of phytosterols, their metabo- lism and role in health and pathological conditions. Phytosterol and phytostanol content in vegetables and functional foods Phytosterols are abundant in vegetable products, such as vegetable oils, fruits, nuts, grains, and pulses (Table 1). T. Bacchetti Á E. Bertoli Á G. Ferretti (&) Dipartimento di Biochimica, Biologia e Genetica, Universita ` Politecnica delle Marche, Via Ranieri, 60131 Ancona, Italy e-mail: g.ferretti@univpm.it S. Masciangelo Á V. Bicchiega Laboratorio Sperimentale di Ricerche Nutrizionali-Istituto Auxologico Italiano (IRCCS), Ospedale S. Giuseppe, Piancavallo (VB), Italy 123 Mediterr J Nutr Metab (2011) 4:165–172 DOI 10.1007/s12349-010-0049-0