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Good cholesterol may not be so beneficial

Category: Heart Health and Cholesterol

Doctors typically view cholesterol test results that reveal high levels of HDL cholesterol as a good thing. However, new evidence calls into question the assumption that these molecules promote heart health.

Researchers from Massachusetts General Hospital analyzed DNA samples and medical records of about 170,000 individuals. They found no association between genetic variants that produce higher HDL levels and a reduced risk of heart attacks or stroke.

The team said the results show that HDL, commonly known as good cholesterol, may not be as beneficial as once thought. Previous studies have shown that HDL molecules can sweep the arteries of plaque buildups, which are risk factors for heart attacks and strokes. However, the importance of this effect may have been overstated.

These previous studies may have mistaken correlation for cause, the researchers said. There are plenty of biomarkers in the blood that may rise and fall along with a person's disease risk. However, this does not mean that those particles actually play an active role in diseases.

"It's been assumed that if a patient, or group of patients, did something to cause their HDL levels to go up, then you can safely assume that their risk of heart attack will go down," said lead researcher Sekar Kathiresan. "This work fundamentally questions that."