Stanol ester is a heterogeneous group of chemical compounds known to reduce the level of low-density lipoprotein (LDL) cholesterol in blood when ingested,[1] though to a much lesser degree than prescription drugs such as statins.[2] The starting material is phytosterols from plants. These are first hydrogenated to give a plant stanol which is then esterified with a mixture of fatty acids also derived from plants. Plant stanol esters are found naturally occurring in small quantities in fruits, vegetables, nuts, seeds, cereals, legumes, and vegetable oils.
Stanol ester is often added to rapeseed oil based margarine or other foods for its health benefits. Studies have indicated that consumption of about 2 grams per day provides a reduction in LDL cholesterol of about 10%. The compound itself passes through the gut without entering the blood stream or lymph. Its presence, however, reduces both the amount of cholesterol the body absorbs from food and the reabsorption of the cholesterol component of bile.
Stanol ester was developed by Ingmar Wester, a Finnish chemist. It is marketed by the Raisio Group with the trade name Benecol.
Sterol esters can also be used for the same purpose. These compounds have the same effect to LDL, but they are partially absorbed by the body. The effects of higher serum plant sterol levels are so far not completely understood.