'Good' Cholesterol Not Always Good for Heart Health

A new study suggests that 'good' cholesterol contains proteins that are bad for the heart. The results, which were presented on August 22^nd at the 234^th national meeting of the American Chemical Society, uncovered more information about the specific proteins of good cholesterol and how they interact with the heart.

Although scientists have been aware of the possibility that altered forms of good cholesterol (called high density lipoprotein (HDL)) are not beneficial to the heart, the makeup of HDL cholesterol has largely remained a mystery.

HDL cholesterol works by removing cholesterol from the artery walls. Scientists have long believed that HDL also had antioxidant and anti-inflammatory properties. So called bad cholesterol or low density lipoprotein cholesterol (LDL) leaves cholesterol in the arteries that can cause clots.

The researchers discovered some previously unknown proteins in HDL that could prevent atherosclerotic plaques from breaking apart, causing clots that then lead to heart attacks. They also identified HDL proteins that protected the heart from damage during a heart attack.

However, other proteins within the HDL structure may inhibit the benefits of the other beneficial proteins. These proteins actually encourage cholesterol to build up in arteries, and prevent the other proteins from fully protecting the heart from damage during a heart attack. The proteins sometimes working at cross purposes indicates that raising HDL cholesterol may not always be the appropriate course of treatment for those with heart disease risks.

"Targeting HDL could represent a new horizon in heart disease diagnosis and treatment," says study leader Jay Heinecke, M.D., of the University of Washington School of Medicine in Seattle in a press release. "But simply boosting HDL levels may not be enough to prevent heart disease. You might have to target the right proteins in HDL."

Earlier this year, a company withdrew a drug that increased HDL cholesterol amid reports that it actually increased the chance of a heart attack or death.