Cholesterol is a waxy, organic substance found in body cells and in blood. The human body uses cholesterol to make cell membranes, vitamin D, hormones, and bile (a liver product). There are two major types of cholesterol, both produced by the liver.
Total cholesterol levels in the body can be affected by genetics and diet. For example, a person may inherit genes that result in low cholesterol or high cholesterol; or a person may eat large amounts of animal products, such as meat, dairy, and eggs, that are high in cholesterol. Exercise, medications, or changes in diet may help lower LDL blood cholesterol levels in humans. Increasing the amount of fiber in a diet, for example, is one specific action that may lower LDL cholesterol levels.