What is Cholesterol?

Cholesterol is a soft, fat-like, waxy substance found in the bloodstream and in all your body’s cells. It’s normal to have cholesterol. It’s an important part of a healthy body because it’s used for producing cell membranes and some hormones, and serves other needed bodily functions. But too high a level of cholesterol in the blood is a major risk for coronary heart disease, which leads to heart attack. It’s also a risk factor for stroke. Hypercholesterolemia is the term for high levels of blood cholesterol.

You get cholesterol in two ways. Your body makes some of it, and the rest comes from cholesterol in animal products that you eat such as meats, poultry, fish, eggs, butter, cheese and whole milk.

Cholesterol and other fats can’t dissolve in the blood. They have to be transported to and from the cells by special carriers called lipoproteins. There are two kinds that you need to know about. Low-density lipoprotein, or LDL, is known as the “bad: cholesterol. Too much LDL cholesterol can clog your arteries, increasing your risk of heart attack and stroke. High-density lipoprotein, or HDL, is known as the “good” cholesterol. Your body makes HDL cholesterol for your protection. It carries cholesterol away from your arteries. Studies suggest that high levels of HDL cholesterol reduce your risk of heart disease.

Why is LDL cholesterol considered “bad”?

When too much LDL cholesterol circulates in the blood, it can slowly build up in the inner walls of the arteries that feed the heart and brain. Together with other substances it can form plaque, a thick, hard deposit that can clog those arteries. This condition is known as atherosclerosis.

Why is HDL cholesterol considered “good”?

About one-third to one-fourth of blood cholesterol is carried by high-density lipoprotein (HDL). HDL cholesterol is known as the “good” cholesterol because a high level of it seems to protect against heart attack. Some experts believe that HDL removes excess cholesterol from plaque in arteries, thus slowing the buildup.

What is Lp(a) cholesterol?

Lp(a) is a genetic variation of plasma LDL. The way an increased Lp(a) contributes to disease isn’t understood.

The triglyceride connection…

Triglyceride is a form of fat. It comes from food and is also made in your body. People with high triglycerides often have a high total cholesterol, a high LDL cholesterol and a low HDL cholesterol level. Many people with heart disease, diabetes or who are obese are also likely to have high triglycerides.

What are Healthy Levels of Cholesterol?

Your total blood cholesterol level will fall into one of these categories:

• Desirable – less than 200 mg/dL
• Borderline high risk – 200 – 239 mg/dL
• High risk – 240 mg/dL and over

Desirable –

Your heart attack risk is relatively low, unless you have other risk factors. Have your cholesterol levels measured every five years – or more often if you’re a man over 45 or a woman over 55.

Borderline high risk –

About a third of American adults are in this (borderline) group; almost half of adults have total cholesterol levels below 200 mg/dL.

Have your cholesterol and HDL rechecked in one to two years if:

• Your total cholesterol is in this range
• Your HDL is less than 40 mg/dL
• You don’t have other risk factors for heart disease

You should also lower your intake of foods high in saturated fat and cholesterol to reduce your blood cholesterol level to below 200 mg/dL. Ask your doctor to discuss you LDL cholesterol with you. Everyone’s case is different.

High Risk –

Your risk of heart attack and stroke is greater. In general, people who have a total cholesterol level of 240 mg/dL have twice the risk of heart attack as people whose cholesterol level is 200 mg/dL. You need more tests. Ask your doctor for advice. About 20 percent of the U.S. population has high blood cholesterol levels.

Your LDL Cholesterol level greatly affects your risk of heart attack and stroke. In fact, it’s a better gauge of risk than total blood cholesterol. Your LDL cholesterol will fall into one of these categories:

If you can’t lower your cholesterol with exercise and a weight management program, medications may also be prescribed to lower your LDL cholesterol.

LDL level at which to consider drug therapy

*In men less than age 35 and premenopausal women with LDL cholesterol levels of 190 to 219 mg/dL, drug therapy should be delayed except in high-risk patients such as those with diabetes.

**In coronary heart disease patients with LDL cholesterol levels of 100 to 129 mg/dL, the doctor should consider whether to initiate drug treatment in addition to the American Heart Association Therapeutic Lifestyle Changes (TLC) diet.

Your HDL cholesterol level –

Low HDL cholesterol puts you at high risk for heart disease. If you have low HDL cholesterol, you can help raise it by:

• Not smoking
• Losing weight (or maintaining a healthy weight)
• Being physically active for at least 30 – 60 minutes a day on most or all days of the week

Progesterone, anabolic steroids and male sex hormones (testosterone) also lower HDL cholesterol levels. Female sex hormones raise HDL cholesterol levels.

Special Message for Women

As a rule, women have higher HDL cholesterol levels than men do. The female sex hormone estrogen tends to raise HDL cholesterol, which may help explain why premenopausal women are usually protected from developing heart disease.

Cholesterol in Children

There is compelling evidence that the atherosclerotic process (buildup of fatty plaque in arteries) begins in childhood and progresses slowly into adulthood. Then it often leads to coronary heart disease, the major cause of death in the United States.

There is evidence that:

• Atherosclerosis or its precursors begin in young people.
• Elevated cholesterol levels early in life may play a role in the development of adult atherosclerosis.
• Eating patterns and genetics affect blood cholesterol levels and coronary heart disease risk.
• Lowering levels in children and adolescents may be beneficial.
• Cigarette smoking should be discouraged.
• Regular aerobic exercise should be encouraged.
• High blood pressure should be identified and treated.
• Obesity should be avoided or reduced.
• Diabetes mellitus should be diagnosed and treated.

Cholesterol levels in children and adolescents 2-19 years old
Total cholesterol (mg/dL)
Acceptable — less than 170
Borderline — 170-199
High — 200 or greater

LDL cholesterol (mg/dL)
Acceptable — less than 110
Borderline — 110-129
High — 130 or greater

Source American Heart Association

Updated: December 28, 2004