Most Americans are familiar with the term "high cholesterol." You probably know that cholesterol is bad, and that too much of it can lead to heart disease and stroke. Cholesterol also plays an important role in many of the body's functions, and some cholesterol is essential to good health.
Function
Cholesterol is a main component of the cell membrane. The cell membrane surrounds each cell in your body. It holds the cell together and regulates the flow of nutrients and wastes from the cell to the bloodstream. Hormones, the chemicals that regulate the functions of metabolism and reproduction, consist largely of cholesterol. Your body also uses cholesterol to make bile, the digestive juice secreted by the small intestine.
Source
Your body not only obtains cholesterol through your diet, but it also makes cholesterol. According to the American Heart Association, your liver makes about 75 percent of the cholesterol in your blood. Dietary sources of cholesterol include meats and fried foods. Although overweight people are more likely to have high cholesterol, thin people can have high cholesterol as well.
Identification
Cholesterol does not dissolve in water, so it is transported through the body in particles called lipoproteins. Lipoproteins consist of cholesterol molecules, fat molecules and proteins. Lipoproteins are identified by their size and density. Low-density lipoproteins carry cholesterol molecules from the liver to the tissues that need them. High-density lipoproteins carry extra cholesterol from the body tissues back to the liver.
Misconceptions
Cholesterol is sometimes labeled "good cholesterol" and "bad cholesterol." Many people assume that there are different types of cholesterol. In fact, all cholesterol molecules are the same. The "good" and "bad" labels are given to the different sizes of lipoprotein particles. Low-density lipoproteins (LDL) are the "bad cholesterol." Although their main function is to carry cholesterol molecules to the tissues of the body, they can also collect on the walls of the arteries to form plaques. These plaques can block the arteries, and sometimes break free to cause heart attack and stroke.
Benefits
"Good Cholesterol," or high-density lipoprotein (HDL), carries unused cholesterol particles from the tissues back to the liver. Along the way, high-density lipoprotein can pick up excess "bad cholesterol" and prevent it from forming plaques on the walls of the arteries. The American Heart Association states that an HDL level of 40 mg/dL (milligrams of cholesterol per deciliter of blood) can protect you from developing heart disease.
Prevention/Solution
When your LDL is too high (above 130 mg/dL) or your HDL is too low (below 40 mg/dL) you have an increased risk of heart disease or stroke. There are several things you can do to keep your cholesterol at optimum levels. Eating a low-fat diet with lots of fruits, vegetables and whole-grain foods can reduce the amount of cholesterol you obtain through food. Also, regular aerobic exercise can help you maintain a healthy cholesterol level. Some people, however, cannot reach a healthy cholesterol level through diet and exercise alone. If this is the case, your doctor may wish to prescribe a cholesterol-lowering drug such as a statin.
