Believe it or not, cholesterol isn't all bad. This soft waxy substance, manufactured in the liver, helps produce hormones, Vitamin D and the bile acids needed to digest fat.
The catch: It takes just a tiny amount of cholesterol to do all this. It's that excess cholesterol in your bloodstream that can lead to arteriosclerosis, a condition in which artery walls can become clogged and narrowed, and arteriosclerosis can cause heart disease or stroke.
What do the numbers mean? Like oil and water, cholesterol (which is fatty) and blood (which is watery) don't mix well. So, cholesterol travels through the bloodstream, together with protein, in packages called lipoprotein. Different kinds of lipoprotein affect your heart.
- Low-density Lipoprotein (LDL): Often called "bad" cholesterol. Low-density lipoprotein carry most of the cholesterol in the blood, and LDL cholesterol is the primary source of artery blockage. The more LDL cholesterol you have in your blood, the higher your risk of heart disease.
- High-density Lipoprotein (HDL): Often called "good" cholesterol. High-density lipoprotein carries cholesterol in the blood from other parts of the body back to the liver, which leads to its removal from the body. So it helps keep cholesterol from building up on artery walls. The higher your HDL level, the better.
- Triglycerides: All fats in the bloodstream, other than cholesterol, are triglycerides. High triglycerides may be a sign of a lipoprotein problem that can lead to heart disease.
Knowing your family medical history helps you determine your risk of developing high cholesterol and possible heart disease. If your parents, uncle, aunt or other close relative developed heart disease at an early age, you're in a high-risk group and should be tested.
Lowering your cholesterol: Want to bring those numbers down? Here are some tips:
- Cut the fat - cutting saturated fats is much more important than avoiding foods containing cholesterol because it's saturated fat that raises cholesterol levels in the body. So, choose poultry, fish and lean meats. Trim meats and remove chicken skin. Substitute skim milk for whole milk. Use tub margarine or liquid vegetable oils, which are higher in polyunsaturated fat (safflower and corn oils, for example) instead of butter, lard and hydrogenated vegetable shortening, which are high in saturated fat. Substitute fruit, veggies and whole grains for highly processed fast foods and snack foods. Buy low-fat mayonnaise and salad dressing. And try fat-free cooking techniques such a broiling, steaming and roasting.
- Lose weight if you're overweight. Losing weight causes overall circulatory fat to go down.
- Get off the couch. Walking even 20 to 30 minutes a day can lower cholesterol.
- Talk to your doctor.
Guide to fats and cholesterol
There are three main types of fats:
- Monounsaturated: Tends to lower LDL-cholesterol levels. Found mostly in plants and seafoods. Olive and canola oil are high in monounsaturated fat.
- Polyunsaturated: Tends to lower both HDL and LDL cholesterol levels. Found mostly in plant and seafoods. Safflower oil and corn oil are high in polyunsaturated fat. Sorry, no oil can help raise HDL levels.
- Saturated: Tends to raise LDL cholesterol levels. Elevated LDL levels are associated with heart disease. Found mostly in animal products such as meat, whole milk, butter and lard.
A new term recently has been added to the diet dictionary: trans fatty acids. These fats don't occur in nature. They are the result of a process called hydrogenation, which converts a liquid fat to a solid fat. Trans fatty acids often are found in baked goods and other highly processed foods and should be avoided by anyone trying to lose weight or lower cholesterol.
How much fat should you eat? The American Heart Association recommends the following guidelines:
- No more than 8 to 10 percent of total calories from saturated fat. People with a history of heart disease should consume less than 7 percent of calories from saturated fat.
- No more than 30 percent of total calories from all types of fat.
- Daily intake of dietary cholesterol should be less than 300 milligrams - less than the amount contained in two eggs - and no more than 200 milligrams for people with a history of heart disease.