If you've ever gone to the grocery store or food market, you've probably seen foods with labels on them that say "low in cholesterol." But what is cholesterol, and why is it a good thing for food to be low in it?

Cholesterol and Your Body

Cholesterol (say: kuh-les-tuh-rawl) is a type of fat found in your blood.

Your liver makes cholesterol for your body. You also can get cholesterol from the foods you eat. Meat, fish, eggs, butter, cheese, and whole or low-fat milk all have cholesterol in them.

You Need a Little, Not a Lot

You need some cholesterol to help your brain, skin, and other organs grow and do their jobs in the body. But eating too much of it is a bad idea, especially for people whose bodies already make too much cholesterol.

It floats around in your blood and can get into the walls of the blood vessels and stay there. If you have too much cholesterol in your bloodstream, a lot can collect in the blood vessel walls, causing these "pipes" to become narrower. This can clog the blood vessels and keep blood from moving freely the way it's supposed to.

If the clogging gets worse over many years, it can cause damage to important body parts, like the heart (heart attack) and brain (stroke). Both kids and adults can have too much cholesterol in their blood.

Doctors can find out what your cholesterol level is by taking a little of your blood and testing it.

Two Types of Cholesterol

There are two main types of cholesterol: HDL and LDL. Most cholesterol is LDL (low-density lipoprotein) cholesterol. LDL cholesterol is more likely to clog blood vessels because it carries the cholesterol away from the liver into the bloodstream, where it can stick to the blood vessels.

HDL (high-density lipoprotein) cholesterol, on the other hand, carries the cholesterol back to the liver where it is broken down.

Here's a way to remember the difference: the LDL cholesterol is the bad kind, so call it "lousy" cholesterol — "l" for lousy. The HDL is the good cholesterol, so remember it as "healthy" cholesterol — "h" for healthy.

Cholesterol and Eating Well

What are some foods that have a lot of cholesterol? Meat, eggs, butter, cheese, and milk (and stuff that's made with some of these things, like most cakes) have cholesterol. Fruits, vegetables, and grains (like oatmeal) don't have any cholesterol.

In addition to cholesterol, it's a good idea to limit the amount of saturated fats and trans fats, which can raise cholesterol levels in your blood. They are most often found in high-cholesterol foods, some margarines, and many store-bought baked goods like cookies, crackers, and snack cakes.

It's also a good idea to get plenty of exercise to help control the amount of cholesterol in your blood and keep your heart and blood vessels healthy.

Reviewed by: Mary L. Gavin, MD
Date reviewed: October 2011