New discovery pinpoints when good cholesterol becomes harmful

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We have heard till now that good cholesterol is good. Right?! But … wait ....

Researchers have discovered that certain components of so-called "good" cholesterol—high-density lipoproteins (HDL)—may be associated with an increased prevalence of cardiovascular disease.

Wait! What?

Surprized? Yes, new data asks for revisits.

Yes, not all cholesterol is born the same. What is not commonly recognized is that each type of cholesterol has two forms—free cholesterol, which is active and involved in cellular functions, and esterified, or bound, cholesterol, which is more stable and ready to be stored in the body. Too much free cholesterol, even if it is in HDL, could contribute to heart disease. Hmmm!

In pre-clinical studies, the research team discovered that HDL with a high content of free cholesterol is likely dysfunctional. To validate their findings and prove their hypothesis, they are currently at the halfway point of the Houston Heart Study in which they will be studying 400 patients with a range of plasma HDL concentrations.

The most surprising finding from this new study thus far is that there is a strong link between the amount of free cholesterol in HDL and how much of it accumulates in white blood cells called macrophages, which can contribute to heart disease.

While it was previously thought that the transfer of free cholesterol to HDL was beneficial for heart health by removing excess cholesterol from tissues, the new data shows that in the context of high plasma HDL concentrations, the reverse is true, wherein free cholesterol transfer from HDL to the white blood cells in blood and tissues could actually raise one's risk for cardiovascular disease.

The researchers say once they reach their immediate goal of showing that excess free cholesterol in HDL is associated with excess cardiovascular disease, they plan to develop new diagnostics and treatments for managing heart disease, as well as use HDL-free cholesterol as a biomarker to identify patients requiring HDL-lowering therapies.

Now that you are confused, what should you do?

Wait for more clarification and confirmation studies while still taking care of your heart's health.

Dedipya Yelamanchili et al, HDL-free cholesterol influx into macrophages and transfer to LDL correlate with HDL-free cholesterol content, Journal of Lipid Research (2024). DOI: 10.1016/j.jlr.2024.100707