For half a century cholesterol has been divided into good and bad categories. Low-density lipoprotein is considered the “Bad” cholesterol as it’s responsible for blocking arteries and causing stroke or heart attacks, while high-density lipoprotein has been seen as the “Good” form of cholesterol as it catches LDL in the bloodstream and takes it back to the liver.
Back in the 1970s a foundational research project, called the Framingham Heart Study, detected a consistent link between increased HDL levels and decreased heart attack risk. The association has informed clinical practice for the decades since it was found, with doctors frequently suggesting higher HDL levels can be protective against heart attack.
Nathalie Pamir, from the Oregon Health & Science University and senior author on the new study, said it is important to understand the racial differences that could be at play when analyzing the effect of HDL levels on heart attack risk.
“It’s been well accepted that low HDL cholesterol levels are detrimental, regardless of race. Our research tested those assumptions.”
Looking at so-called “Good” HDL cholesterol, the research found low levels only correlated with increased heart disease in White adults. Perhaps most striking, high HDL levels were not associated with less heart attacks in either White or Black study participants.
It’s currently unclear why HDL cholesterol would have a different impact on heart disease risk between ethnicities.
Sean Coady, an epidemiologist from the National Heart, Lung, and Blood Institute said these findings call for more study into the properties of HDL cholesterol.
“HDL cholesterol has long been an enigmatic risk factor for cardiovascular disease,” said Sean Coady, who didn’t work on this new study.