What Is Cholesterol?

Cholesterol is a waxy, fat-like substance that is made in the body by the liver. Cholesterol forms part of every cell in the body and serves many vital functions. Our bodies need cholesterol to:

Maintain healthy cell walls
Make hormones (the body's chemical messengers)
Make vitamin D
Make bile acids, which aid in fat digestion

Sometimes, however, our bodies make more cholesterol than we really need, and this excess cholesterol circulates in the bloodstream. High levels of cholesterol in the blood can clog blood vessels and increase the risk for heart disease and stroke.

Our bodies can make too much cholesterol when we eat too much saturated fat - the kind of fat found in animal-based foods such as meat and dairy products.

In addition to making cholesterol, we also get a small percentage of our body's cholesterol from the foods we eat. Only animal-based foods such as meat, eggs, and dairy products contain cholesterol. Plant foods such as fruits, vegetables, and grains do not contain cholesterol.

The Different Types Of Cholesterol

There are different types of cholesterol - and not all cholesterol is harmful.

Low-density lipoprotein (or LDL) cholesterol is a bad type of cholesterol that is most likely to clog blood vessels, increasing your risk for heart disease.

High-density lipoprotein (or HDL) cholesterol is a good type of cholesterol. HDL cholesterol helps clear the LDL cholesterol out of the blood and reduces your risk for heart disease.

Facts About Cholesterol

More than one-half of American adults have blood cholesterol levels that are too high.

Lowering your cholesterol level has a double payback: For every one percent you lower your blood cholesterol level, you reduce your risk for heart disease by two percent.

Even if you already have heart disease, lowering your cholesterol levels will significantly reduce your risk for death and disability.

As blood cholesterol exceeds 220 ml/dl (milligrams per deciliter, which are the units in which blood cholesterol is measured in the United States), risk for heart disease increases at a more rapid rate.

All adults should have their blood cholesterol level measured at least once every five years.

The liver makes most of the cholesterol in our bodies-only a small percentage comes from food. But the more saturated fat we eat, the more cholesterol our bodies make.

Most people can bring down their blood cholesterol levels without medication by changing the way they eat and by becoming more active.

Only animal foods contain cholesterol; plant foods do not contain cholesterol.

A medium egg contains about 213 milligrams of cholesterol, a three-ounce portion of lean red meat or skinless chicken contains about 90 milligrams of cholesterol, and a three-ounce portion of fish contains about 50 milligrams of cholesterol.