Sterol-enriched margarine. Sterols are naturally occurring substances present in the diet as minor components of vegetable and seed oils. An elevated level of blood cholesterol is a well established risk factor for coronary heart disease. Plant sterols are effective in lowering plasma total cholesterol and low density lipoprotein (LDL) cholesterol. They do this by inhibiting absorption of cholesterol from the small intestine. For a significant reduction to occur, the normal dietary intake of sterols needs to be supplemented for a period of several weeks. It has been found that sterols dissolved in edible fats are more effective than sterols taken in crystalline form.