Cholesterol is a soft waxy substance found in the bloodstream. Cholesterol has many positive uses in the body, such as strengthening cellular walls. However, too much cholesterol can lead to heart disease and death.
Molecules of cholesterol are transported through the bloodstream by carrier molecules called lipo-proteins. There are two types of cholesterol carriers, high density lipo-proteins (HDL) and low density lip-proteins (LDL).
LDL is commonly referred to as "bad cholesterol," because it builds up on the arterial walls and can block the flow of blood to and from the heart. HDL is commonly referred to as "good cholesterol," since it removes LDL from the blood and carries it to the liver to be metabolised.
High levels of LDL cholesterol are associated with an increased risk of heart disease and death, according to the American Heart Association. Acceptable LDL levels are 160 milligrams per decilitre of blood in healthy persons, and 100 mg per decilitre of blood or lower in persons at risk for heart disease.
Higher levels of HDL cholesterol provide protection from the negative effects of LDL and are associated with reduced risk of heart disease. Acceptable levels of HDL are a minimum of 40 milligrams per decilitre and ideally 60 milligrams per decilitre or higher.
The American Heart Association has established acceptable levels of total blood cholesterol (HDL and LDL combined) for healthy persons. Normal total blood cholesterol is 200mg/dl or lower, while 240mg/dl and higher is considered high cholesterol.
To reduce the risk of high cholesterol, eat a diet that is low in saturated fats, but high in fruits and vegetables. Avoid tobacco products and excess alcohol consumption, and exercise regularly.