Waxy organic compound found in blood and all animal tissues. It is a steroid , with molecular formula C 27 H 46 O, containing four rings in its structure. Cholesterol is essential to life; it is a primary component of cell bile acids, other steroid hormones , and vitamin D . It is made in the liver and some other organs, in greater or lesser amounts depending on the amount recently consumed in the diet. It circulates in the blood in compounds called lipoproteins , since it is not water-soluble alone. Excess cholesterol in the blood forms deposits in arteries (see arteriosclerosis ), which can lead to coronary heart disease . Michael Brown
born 1941
and Joseph Goldstein
born 1940
won a Nobel Prize in 1985 for their work in discovering this process.
Since the body makes cholesterol from fats , blood cholesterol cannot be reduced by limiting only the amount of cholesterol in the diet; the amount of fat, especially saturated fat (see {{link=saturation">saturation , fatty acid ) must also be reduced. See also triglyceride .