Cholesterol is a Major Building Block ..

Cholesterol is manufactured in the liver for normal body functions, including the production of hormones, bile acid, and vitamin D. Cholesterol is required to build and maintain cell membranes; it regulates membrane fluidity over a wide range of temperatures. Cholesterol is a building block in many important cell components especially the cell membrane and is the starting point for several hormones. About one third to one fourth of the total amount of cholesterol is HDL cholesterol.

HDL cholesterol is called the "good cholesterol" because HDL cholesterol particles prevent atherosclerosis by extracting cholesterol from the artery walls and disposing of them through the liver. LDL cholesterol is called "bad" cholesterol, because elevated levels of LDL cholesterol are associated with an increased risk of coronary heart disease. Of particular interest is the finding that a high ratio of triglycerides to HDL cholesterol is a powerful risk factor for a major cardiac event even when LDL cholesterol levels are normal. It is now clear that any food that lowers LDL cholesterol or raises HDL cholesterol is what we should be looking for.

Most cholesterol is LDL cholesterol, and this is the kind that's most likely to clog the blood vessels, keeping blood from flowing through the body the way it should. Some cholesterol is normally present in plasma (the liquid part of blood) attached to proteins (lipoproteins) that transport it and other fat molecules around the body. When too much cholesterol is present, plaque (a thick, hard deposit) mayform in the body's arteries narrowing the space for blood to flow to the heart. LDL cholesterol is more likely to clog blood vessels because it carries the cholesterol away from the liver into the bloodstream, where it can stick to the blood vessels.