Cholesterol: The Good, The Bad, And The Triglycerides

We have come a long way from the time when bacon and eggs were daily standard American breakfast fare to today when most third graders are aware that elevated cholesterol levels are bad. But more than half of all Americans have cholesterol levels that exceed the recommended total; one in five Americans have cholesterol levels that are considered "high". With this in mind, Dr. Donnica Moore addresses what we really need to know about cholesterol and what we should do if our numbers are too high. Dr. Moore discusses the different types of cholesterol and fats and shares some insight on how to best manage your own numbers. . .and the factors that got them that way in the first place.

Cholesterol is a soft, waxy, fat-like substance found in many foods, in your bloodstream and in all your body's cells. It is essential for human and animal life: it forms cell membranes, some hormones, and many necessary tissues. But a high level of cholesterol in the blood - called hypercholesterolemia--is a major risk factor for coronary artery disease (CAD, sometimes just called "heart disease"), which can lead to heart attack, disability, and death.

Cholesterol and other fats (lipids) can't dissolve in our blood. They have to be moved between cells by special carriers of lipids and proteins called lipoproteins. There are several kinds of cholesterol carrying lipoproteins, but the ones you should be aware of are low-density lipoprotein (LDL) and high density lipoprotein (HDL).

Cholesterol comes from two sources: internal and external. Internally, it is made in your liver (about 1,000 milligrams a day). Externally, it comes from your diet: from meat, poultry, fish, seafood and dairy products. Foods from plants (fruits, vegetables, grains, nuts and seeds) do not contain cholesterol.

Eating foods high in saturated fatty acids is the chief culprit in raising blood cholesterol, but dietary cholesterol also plays a part. The average American man eats about 360 milligrams of cholesterol a day; the average woman eats between 220 and 260 milligrams daily. Some excess dietary cholesterol is removed from the body through the liver. Still, the American Heart Association (AHA) recommends that you limit your average daily cholesterol intake to less than 300 milligrams.

People with severe hypercholesterolemia may need to eat even less. Since cholesterol is present in all foods from animal sources, these must be limited and lean or low fat.

LDL (low-density lipoprotein) is the major cholesterol carrier in the blood, popularly called "the bad cholesterol". If you have too much LDL, it can slowly build up on the walls of your arteries, especially those to the heart and brain. When combined with other substances, it can form plaque: a thick, hard deposit that can clog those arteries. This is called "atherosclerosis". (For an effective visual image, just think of what happens to your drainpipes when you pour chicken fat down the sink!) If a clot (or thrombus) forms nearby, this plaque can block blood flow to part of the heart and cause a heart attack. If a clot blocks blood flow to the brain, a stroke may result. Therefore, high levels of LDL increase your risk for heart disease and stroke, the top killers of all Americans.

About one-third to one-fourth of blood cholesterol is carried by HDL (high-density lipoprotein). It is believed to carry cholesterol away from the arteries to the liver, where it is processed, thus "clearing" your system (it's the Drano of the kitchen sink example). HDL may also remove excess cholesterol from atherosclerotic plaques and slow their growth. Higher HDL levels may protect against heart attack and stroke, so HDL is known as "good" cholesterol.