"Good" high-density lipoprotein (HDL) cholesterol, which has been always thought to protect against heart disease, may not always live up its reputation. A new study has linked the supposedly good cholesterol to increased heart risks on some people.
The Telegraph reported that the new study from Cambridge University, published in the journal Science, has contradicted to earlier research that recommended HDL cholesterol as protection to the heart. The researchers found that some people with high levels of HDL cholesterol are at much greater risk of heart disease.
The researchers have discovered that one-in-1,700 people suffer a mutation in a gene called SCARB1. Despite having high levels of good cholesterol, people with the rare mutation have an 80 percent increased risk of heart disease, which is just about the same increased risk as for smoking. The researchers found that SCARB1 could prevent the HDL from discarding the fat it had collected in the liver for processing.
"This is significant because we had always believed that good cholesterol is associated with a lower risk of heart disease," Prof. Adam Butterworth, one of the researchers, told the BBC News. "This is one of the first studies to show that some people that have high levels of 'good' cholesterol actually have a higher risk of heart disease so it challenges our conventional wisdom about whether 'good' cholesterol is protecting people from heart disease or not."
According to Prof. Peter Weissberg, British Heart Foundation medical director, the recent study sheds light on one of the major puzzles relating to cholesterol and heart disease. "These new findings suggest that the way in which HDL is handled by the body is more important in determining risk of a heart attack than the levels of HDL in the blood. Only by understanding the underlying biology that links HDL-C with heart attacks can we develop new treatments to prevent them," he stated.
While the recent findings gave direct contradiction to the importance of increased HDL cholesterol levels, the researchers still acknowledged its valuable role in predicting the risk of a heart attack. They added that they will still conduct further study to fully figure out the complex relationship between HDL and risk of heart disease.
