Cholesterol

By Jonny Bowden, PhD, CNS

In recent years, cholesterol has become one of the most maligned molecules on the planet. Most people think of it as a problem, something in our blood that can lead to heart attacks. The obvious response, then, is to try to reduce it to as low a number as possible. But that is a very limited understanding how cholesterol really works.

Cholesterol is soft, waxy matter found among the fats in the bloodstream and in all of the body’s cells. It’s used to create cell membranes and a host of hormones, such as the sex hormones, and hormone-like compounds, including vitamin D. You could not survive without cholesterol.

Good and Bad Cholesterol

For years, experts have known that simply measuring the total amount of cholesterol in the body does not give a complete picture of cardiovascular health. While there are several kinds of cholesterol, most doctors now focus on two types of cholesterol to gauge heart disease risk: HDL (high-density lipoprotein) and LDL (low-density lipoprotein). Lipoproteins in the bloodstream carry cholesterol to and from the cells.

LDL is the major cholesterol carrier in the blood. It is also known as “bad” cholesterol because too much of it may build up in artery walls, leading to plaque and to increased risk for cardiovascular disease. The American Heart Association considers an LDL level of 130 or less optimal for most people, and a level of more than 160 (or more than 130 if you have two other risk factors, such as smoking, high blood pressure or family history of early onset heart disease) a problem. HDL, or “good” cholesterol, transports the remaining cholesterol out of the bloodstream and deposits it in the liver, where it can be processed and excreted. High amounts of HDL protect the heart and levels over 40 are desirable.

It is the ratio of total cholesterol to HDL cholesterol that is the most useful measure of cardiovascular risk. Most health professionals consider a ratio of 4 (or under) to be very low risk. For example, a person with a total cholesterol of 200 and HDL of 50 is at lower risk for heart disease than someone with a total level of 180 and HDL of 30.

Another cardiovascular consideration: triglycerides,a type of fat in your bloodstream. Triglyceride levels of less than 150 are normal, though some doctors like to see numbers that are even lower. A high triglyceride level (200 or over) is an independent risk factor for heart disease and stroke, particularly when coupled with low HDL.

Cholesterol and Your Diet

As anyone who orders an egg white omelette knows, many foods contain varying amounts of cholesterol. Animal products, such as egg yolks, whole-milk dairy products, meat and fish, have more of it, while fruits, vegetables and legumes don’t. But the amount of cholesterol you eat may not have as much to do with the amount in your blood as you might think. In fact, saturated fatty acids and trans fats have stronger effects on your cholesterol levels than the cholesterol in food you consume. In addition, a large proportion of your cholesterol is actually made by your own body, mainly in the liver. So while the American Heart Association recommends that you limit cholesterol -- as well as saturated fats -- avoiding otherwise healthy foods because of their cholesterol content is usually unnecessary. If your LDL levels are too high, consider eating less saturated fats to reach your cholesterol targets. And talk to your doctor about how to best lower your cholesterol.