‘Good’ cholesterol may not be good for everyone as previously thought, study finds

“Good” cholesterol may not be as effective in uniformly predicting the risk of heart disease across adults from different racial and ethnic backgrounds, according to a new study.

The research, published on Monday in the Journal of the American College of Cardiology, suggests lower levels of high density lipoproteins or HDL cholesterol – often called “good” cholesterol – were associated with increased risks for heart attacks in white but not black adults.

The study found that higher levels were not protective for either racial group.

Earlier studies shaping perceptions about “good” cholesterol levels and heart health were conducted in the 1970s through research with a majority of white adult study participants, said scientists, including those from the Oregon Health & Science University, in a statement.

In the new study, researchers reviewed data from 23,901 US adults who participated in the Reasons for Geographic and Racial Differences in Stroke Study (REGARDS).

Participants enrolled in the study between 2003-07 and data collected throughout a 10- to 11-year period was analysed.

From the data, scientists could assess how cholesterol levels from Black and white middle-aged adults without heart disease who lived throughout the US overlapped with future cardiovascular events.

“The goal was to understand this long-established link that labels HDL as the beneficial cholesterol, and if that’s true for all ethnicities,” study senior author Nathalie Pamir.

“It’s been well accepted that low HDL cholesterol levels are detrimental, regardless of race. Our research tested those assumptions,” Dr Pamir added.

During the study time period, 664 black adults and 951 white adults experienced a heart attack or heart attack-related death.

Participants with increased levels of low-density lipoprotein (LDL) “bad” cholesterol and triglycerides had modestly increased risks for heart disease, aligning with previous study findings.

But it was found that HDL cholesterol levels only predicted increased cardiovascular disease risk for white adults.

Higher than optimal amounts of “good” cholesterol may not provide cardiovascular benefits for either group as well, the study noted.

“What I hope this type of research establishes is the need to revisit the risk-predicting algorithm for cardiovascular disease. It could mean that in the future we don’t get a pat on the back by our doctors for having higher HDL cholesterol levels,” Dr Pamir said.

Instead of having more HDL, the quality of HDL’s function – in picking up and transporting excess cholesterol from the body – may be more important for supporting heart health.

“The findings suggest that a deeper dive into the epidemiology of lipid metabolism is warranted, especially in terms of how race may modify or mediate these relationships,” said Sean Coady, another author of the study.

Researchers call for future research with diverse populations to explore these connections.

“When it comes to risk factors for heart disease, they cannot be limited to one race or ethnicity. They need to apply to everyone,” Dr Pamir said.