Where is Cholesterol Produced in the Body

Cholesterol is a type of fat (lipid) made by the body. About 80% of cholesterol is made by the body; the other 20% comes from the diet. It is produced primarily in the liver while smaller amounts are produced by the lining of the small intestine and the cells of the body. Cholesterol is a building block for cell membranes and is used to produce many hormones (e.g., progesterone, estrogen, and testosterone), vitamin D, and the bile acids that help to digest fat.

Many foods contain cholesterol and high intake of these foods can increase the level of cholesterol in the blood. Having too much cholesterol in the blood is not a disease in itself, but high cholesterol (hypercholesterolemia) can cause the formation and accumulation of plaque deposits in the arteries. Plaque is composed of cholesterol, other fatty substances, fibrous tissue, and calcium. When it builds up in the arteries, it results in the hardening and narrowing of the arteries (atherosclerosis) in the major vascular systems.

Narrowing of the arteries around the heart (coronary heart disease) can prevent the heart from getting as much oxygen-rich blood as it needs, increasing the risk of a heart attack. Decreased blood flow to the brain can cause a stroke, and less blood flowing to the lower limbs may result in exercise-related pain or even gangrene.

Having a high cholesterol level does not cause symptoms and does not make you feel sick. If there is a huge excess, some people develop soft, yellowish skin growths called xanthomas, usually in the area near the eyes. Most people find out they have high cholesterol when they have their blood cholesterol measured as part of a medical check-up.

Types of Cholesterol

Cholesterol is not soluble in water and doesn't mix easily with blood. In order to be able to travel in the bloodstream, the cholesterol made in the liver is combined with protein and other substances. This cholesterol-protein package is called a lipoprotein. Lipoprotein then carries the cholesterol through the bloodstream.

Lipoproteins can be high density (HDL), low density (LDL) or very low density (VLDL), depending on how much protein there is in relation to fat.

LDL (low density lipoprotein)

Low-density lipoprotein (LDL) is called the "bad" cholesterol. About 70% of cholesterol is transported as LDL. This is mostly fat and not much protein. LDL causes cholesterol to be deposited in the arteries. High levels of LDL are associated with an increased risk of coronary heart disease.

HDL (high density lipoprotein)

High-density lipoprotein (HDL) is called the "good" cholesterol. It carries cholesterol from the body's tissues back to the liver. About 20% of cholesterol is transported as HDL, which is mostly protein and not much fat. HDL cholesterol may help protect against atherosclerosis by preventing cholesterol from depositing on arterial walls as it circulates in the bloodstream.

Lifestyle changes such as changing diet, managing weight, increasing exercise, and quitting smoking are the first steps to improving blood levels of cholesterol. If these changes are not enough, your physician might recommend cholesterol-lowering prescription medication.

Knowing where is cholesterol produced in the body can help understand that it is an important nutrient for an overall healthy body. But in this case to much additional cholesterol eaten from high cholesterol and fatty foods is too much of a good thing and can have dangerous consequences to your long term health.