The western diet provides about 100-300 mg/day of plant sterols and 20-50 mg/day of plant stanols. Plants sterols and stanols have been incorporated into various food products, including margarine and salad dressing.
Plants sterols such as sitosterol, campesterol and stigmasterol are structurally similiar. Stanols are saturated sterols without double bonds in the sterol ring structure.
The plant sterols mixtures typically used in supplements to reduce cholesterol levels are usually extracted from pine tree wood pulp or soybean oil.
Plant sterols are often hydrogenated forming stanols, and both sterols and stanols can be extracted to make them soluble in fats, forming stanol and sterol esters. They have similar structure to cholesterol and therefore can be absorbed by the gut instead of cholesterol.
Plant sterols and stanols esters compete with dietary cholesterol for absorption via mixed micelles. They block dietary and biliary cholesterol absorption in the small intestine with subsequent reduction of serum cholesterol and LDL concentration.
Sterols lowered total cholesterol by 6-11% and LDL cholesterol by 7-15%. Stanols lowered total cholesterol by 4-10% and LDL cholesterol by 7-14%.
Natural substances of plant sterols and plant stanols
