Plant sterols are cholesterol-like compounds found in plants. They can help lower cholesterol and reduce the risk of heart disease. Since there are low amounts of plant sterols in plant-based foods, these compounds are also available in the form of dietary supplements and functional foods (such as margarine or spreads). Potential side effects of these products include heartburn, nausea, and gas.
Plant sterols are compounds naturally found in the membranes of plant cells. They are the plant versions of cholesterol (which occurs only in animals). These compounds can help lower cholesterol and reduce the risk of heart disease. Although many plant-based foods contain small amounts of plant sterols, there is much interest in using plant sterols as a dietary supplement, especially in the form of functional foods (such as margarines or spreads).
There are many other health benefits that they may provide, some which are more valid than others.
(Click Benefits of Plant Sterols for more information on what they are used for.)
It is thought that they reduce the risk of heart disease mostly by lowering cholesterol. Because they are not absorbed well from the digestive system to the rest of the body, they work mostly within the digestive system. They work primarily by blocking the absorption of cholesterol from the intestine.
There is good evidence that they can lower cholesterol levels and may reduce the risk of heart disease. There is not enough evidence to tell if they are effective for other uses as well (see Do Plant Sterols Work? for more information).