The Downside of Good Cholesterol

Rebecca Lewis January 28, 2014

HDL cholesterol, known as the ‘good cholesterol’, is needed to keep arteries clear and the heart healthy. But a new study found that it also has a nasty side effect. The findings, published in the journal Nature Medicine, suggest that good cholesterol can become abnormal, leading to blocked blood vessels.

Low-density lipoprotein (LDL) cholesterol is considered ‘bad’ because it is deposited in the walls of arteries and causes the build-up of plaques that can later on cause blockages, thus, increasing the risk of heart attack and stroke. Meanwhile, high-density lipoprotein (HDL) cholesterol is "good" because the cholesterol is instead shipped to the liver.

According to the researchers, trials aimed at boosting levels of HDL have "not been successful" and the role of good cholesterol is clearly more complicated. One of the researchers, Dr Stanley Hazen, said HDL cholesterol was being modified in the walls of the artery. "In the artery walls it is acting very differently to in the circulation. It can become dysfunctional, and contributes to the development of heart disease.” he told BBC.

Their tests, which involved 627 patients, showed that levels of abnormal HDL in the blood could be used to predict the risk of cardiovascular disease.

"Identifying the structure of dysfunctional apoA1 and the process by which it becomes disease-promoting instead of disease-preventing is the first step in creating new tests and treatments for cardiovascular disease," said Dr. Hazen. "Now that we know what this dysfunctional protein looks like, we are developing a clinical test to measure its levels in the bloodstream, which will be a valuable tool for both assessing cardiovascular disease risk in patients and for guiding development of HDL-targeted therapies to prevent disease."

"This data does not change the message of eat healthily." Instead, findings would be used to develop new tests for abnormal HDL cholesterol and research on drugs to help block its formation, Dr Hazen added.

"This interesting research pins down the exact chemical change that causes the ’good’ HDL cholesterol to become bad.” said Dr Shannon Amoils, a senior research adviser for the British Heart Foundation. "This knowledge could allow scientists to monitor coronary artery disease more closely or even target the ’bad’ HDL with drugs."

Source of this article:

Good cholesterol ’can turn nasty and clog arteries’