Keeping Cholesterol Under Control: "Cholesterol is the Jekyll and Hyde of the body.
Like the literary split personality, it has a good side because it is needed for certain important body functions. But for many Americans, cholesterol also has an evil side. When present in excessive amounts, it can injure blood vessels and cause heart attacks and stroke.
The body needs cholesterol for digesting dietary fats, making hormones, building cell walls, and other important processes. The bloodstream carries cholesterol in particles called lipoproteins that are like blood-borne cargo trucks delivering cholesterol to various body tissues to be used, stored or excreted. But too much of this circulating cholesterol can injure arteries, especially the coronary ones that supply the heart. This leads to accumulation of cholesterol-laden 'plaque' in vessel linings, a condition called atherosclerosis.
When blood flow to the heart is impeded, the heart muscle becomes starved for oxygen, causing chest pain (angina). If a blood clot completely obstructs a coronary artery affected by atherosclerosis, a heart attack (myocardial infarction) or death can occur. (See 'How a Heart Attack Happens.')"