The liver manufactures and secretes LDL cholesterol into the
blood. It also removes LDL cholesterol from the blood by active LDL receptors
on the surface of its cells. A decrease number of liver cell LDL receptors is
associated with high LDL cholesterol blood levels.
Both heredity and diet have a significant influence on a
person's LDL, HDL and total cholesterol levels. For example, familial
hypercholesterolemia (hyper= more + cholesterol + emia= in blood) is a common
inherited disorder whose victims have a diminished number or nonexistent LDL
receptors on the surface of liver cells. People with this disorder also tend to
develop atherosclerosis and heart attacks during early adulthood.
Diets that are high in saturated fats and cholesterol raise
the levels of LDL cholesterol in the blood. Fats are classified as saturated or
unsaturated (according to their chemical structure). Saturated fats are derived
primarily from meat and dairy products and can raise blood cholesterol levels.
Some vegetable oils made from coconut, palm, and cocoa are also high in
saturated fats.