Phytosterols: natural compounds with established and emerging health benefits

Abstract

Phytosterols (plant sterols and stanols) are naturally occurring compounds which are found in all foods of plant origin. The term phytosterols refers to more than 200 different compounds. The most abundant ones in the human diet are sitosterol and campesterol. Their saturated counterparts, sitostanol and campestanol, are found in much lower amounts. Good food sources of phytosterols include vegetable oils, cereal grains, nuts, legumes, and fruits and vegetables. Phytosterols are structurally similar to cholesterol. Despite this structural similarity, they are not absorbed in significant quantities. Absorption is less than 2% for phytosterols, while it is 30-60% for cholesterol. Phytosterols are known to have various bioactive properties, which may have an impact on human health, and as such boosted interest in phytosterols in the past decade. The most important benefit is their blood cholesterol-lowering effect via partial inhibition of intestinal cholesterol absorption. The recommended daily intake of 2 g of phytosterols reduces cholesterol absorption by 30-40% and LDL-cholesterol by 10% on average. Other claimed benefits of phytosterols are possible anti-atherogenic effects as well as, particularly for beta-sitosterol, immune stimulating and anti-inflammatory activities. Furthermore, there is emerging evidence suggesting that particularly plant sterols may have beneficial effects against the development of different types of cancers, like colorectal, breast and prostate cancers. It is not clear whether mechanisms other than the established cholesterol-lowering action of phytosterols as such also contribute to these potential health benefits.

Keywords

• phytosterols
• health benefits
• cholesterol-lowering
• LDL-cholesterol
• atherosclerosis
• immunity
• inflammation
• cancer
• benign prostate hyperplasia