What is Cholesterol?

Cholesterol is a waxy substance the body uses to protect nerves, make tissues and produce certain hormones. Our liver makes most of the cholesterol in the body. Some cholesterol also comes from foods such as eggs, meats and dairy products.

Cholesterol is an essential ingredient of many physiological body functions. For example, it helps produce bile, combines hormones and vitamin D, and metabolises fat-soluble vitamins (A, D, E, K). It is, therefore, important to keep cholesterol levels within an ideal range, not too low and not too high.

Cholesterol problems can result when your digestive organs cannot properly digest the fats or proteins you consume. When your body cannot digest fats or proteins, your liver does not receive the nutrition it needs to process cholesterol correctly. This can cause your cholesterol levels to rise.

The main cause of high blood cholesterol is eating too much fat, especially saturated fat. Saturated fats are found in animal products, such as meats, milk and other dairy products that are not fat free, butter, and eggs. Some of these foods are also high in cholesterol. Fried fast foods and snack foods often have a lot of fat.

Types of Cholesterol

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.

LDL particles actually vary in size and density, and studies have shown that a pattern that has more small dense LDL particles-called "Pattern B"-equates to a higher risk factor for coronary heart disease (CHD) than does a pattern with more of the larger and less dense LDL particles ("Pattern A"). This is because the smaller particles are more easily able to penetrate the endothelium. "Pattern I," meaning "intermediate," indicates that most LDL particles are very close in size to the normal gaps in the endothelium (26 nm). HDL (high density lipoprotein)

High-density lipoprotein (HDL) is called the "good" cholesterol. Medical experts think HDL tends to carry cholesterol away from the arteries and back to the liver, where it's passed from the body. Some experts believe HDL removes excess cholesterol from plaques and thus slows their growth. HDL is called "good" cholesterol because it helps prevent cholesterol from building up in your arteries. It is mostly protein with only a small amount of fat.

For more information, visit Discovery Health Web.