More Good News About the 'Good' Cholesterol
June 5, 2001 -- High levels of that "good" HDL cholesterol have been known to protect against heart disease. Now a new study shows that high HDL levels also protect people from suffering a stroke. Published in the June 6 issue of Journal of the American Medical Association, the study is the first study to clarify the relationship between cholesterol and stroke.
According to the National Stroke Association, stroke is the third leading cause of death in the U.S. As such, researchers are working hard to determine what places people at particularly high risk for stroke. As with heart disease, cholesterol has long been considered a culprit, but the relationship between cholesterol and stroke is not as clear as the relationship between cholesterol and heart disease.
To complicate matters further, "cholesterol" is another grab bag term referring to several different types of fatty substances found in the blood -- some good and some bad. Traditionally, LDL cholesterol is considered the "bad" unhealthy type that clogs arteries, which can lead to heart disease and stroke. HDL cholesterol, on the other hand, is actually good to have in the blood, as it prevents the fatty substances from building up in the blood vessels.
"Until relatively recently, the relationship between cholesterol and stroke risk, unlike the relationship between cholesterol and heart disease, has been unclear," expert Larry Goldstein, MD, tells WebMD. "One of the nice things about this study is they look very carefully at different stroke subtypes in the population."
In this study, the researchers found that increased HDL protects against strokes called atherosclerotic strokes, which can be triggered when fatty deposits clog the blood vessels. This is similar to how HDL protects against heart disease, says Goldstein, who is director of the Center for Cerebrovascular Disease at Duke University in Durham, N.C., and a member of the National Stroke Association.
Atherosclerotic stroke differs from both embolic stroke, in which a blood clot develops elsewhere in the body and travels to the blood vessels leading to the brain to create a blockage, and hemorrhagic stroke, in which a blood vessel in the brain bursts.