You?re probably just as tired of hearing about cholesterol as I am. But I bet you don?t know nearly enough about triglycerides.
Triglycerides are considered saturated, monounsaturated, or polyunsaturated, depending on the saturation of the fatty acids they contain. Like cholesterol, triglycerides are fats (lipids) that are always present in your blood. Unlike cholesterol, which you?ve never seen, you confront triglycerides all the time because they comprise almost all of the fat in our diets. In fact, butter, margarine, olive oil, and corn oil are pure triglycerides, as is most of the fat you should remove from meat.
The triglycerides in body fat (adipose tissue) serve as our major reservoir of energy. Some of the triglycerides in our blood and adipose tissue come from dietary fat. The liver also converts excessive amounts of dietary carbohydrates (sugars and starches) into triglycerides.
Cells in our intestines package triglycerides absorbed from the diet into particles that transport the triglycerides to muscles for use as energy, to adipose tissue for storage, and to the liver.
The liver uses triglycerides to produce very low density lipoprotein (VLDL), which is released into the blood. Enzymes in the blood remove triglycerides from VLDL to form low density lipoprotein (LDL, which carries the so-called bad cholesterol). Intermediate products of the conversion of VLDL to LDL are termed VLDL remnants. Both VLDL remnants and LDL carry cholesterol into artery walls and form atherosclerotic plaques.
After an overnight fast, normal blood levels of triglycerides are less than 150 mg/dL. Triglyceride levels greater than 500 mg/dL can cause repeated attacks of acute pancreatitis, a painful and life-threatening disorder. More modest elevations of triglycerides, between 200 and 500 mg/dL, increase the risk of atherosclerosis and coronary artery disease in several ways: the blood contains larger amounts of plaque-forming VLDL remnants, levels of protective HDL are often reduced, and LDL is present in a more damaging form. More about triglycerides in coming entries.
For more information read Triglycerides, Part 2: Hypertriglyceridemia.
