Phytosterols: perspectives in human nutrition and clinical therapy

Phytosterols (PSs) are a group of plant derived steroid alcohols, with wide occurrence in vegetables and fruits. They are integral components of plant cell membranes, having stabilizing effects on phospholipids bilayer, just like cholesterol in animal cell membranes. Structural resemblance of PSs with cholesterol enables them to displace low-density lipoprotein (LDL) cholesterol in the human intestine. Protective effects of PSs against cardiovascular diseases (CVDs), colon and breast cancer developments have been widely documented. Several reports have been published on the potential dietary intake of common PSs, such as β-sitosterol, stigmasterol and campesterol, and their safety concerns. Ability of PSs to reduce cholesterol levels and risks associated with heart problems has made them a class of favorite food supplements. Nowadays functional foods supplemented with PSs have become an alternative and healthy tool to lower LDL-cholesterol levels in a natural way. However, excessive use of PSs has been observed to develop premature coronary artery disease in phytosterolemic patients, high risk of atherosclerotic CVDs, myocardial infarction and even impaired endothelial functions. This manuscript will highlight the recent developments in PSs with particular focus on their role as dietary supplements and in treatment of various heart- and cholesterol-related ailments. Recently explored side effects of PSs will also be discussed.