It works. Lowering LDL cholesterol reduces heart attacks, strokes and early death. But this doesn’t tell the whole story.
The LDL cholesterol test measures the amount of cholesterol inside low-density lipoprotein particles circulating in the bloodstream. Cholesterol-containing LDL particles can become trapped in artery walls, forming plaques that can eventually block blood flow. Because the test measures the amount of cholesterol, not the number of LDL particles, two people may have the same level of LDL cholesterol but very different numbers of particles, and therefore have different levels of risk.
That difference has led researchers to a different way of measuring risk. Apolipoprotein B, or apoB, refers to the total number of cholesterol-carrying particles in the blood, rather than how much cholesterol they contain. Growing research suggests it is a more accurate way to identify who is at risk and who is not.
It was recognized by the American Heart Association and the American College of Cardiology in March 2026. Their updated cholesterol guidelines acknowledged apoB as a potentially more accurate marker, in line with earlier European recommendations. But they stopped short of recommending apoB as the primary method for testing.
“They review the evidence and find apoB to be superior, but the real rules of the road continue to prioritize LDL,” says Alan Snyderman, a cardiologist at McGill University.
Snyderman was the author of a 2026 JAMA modeling study that analyzed lifetime outcomes of approximately 250,000 American adults eligible for statin treatment. Comparing LDL cholesterol, non-HDL cholesterol, and apoB, the study found that using apoB to guide treatment decisions would prevent more heart attacks and strokes than current methods, while remaining cost-effective.
ApoB testing can be done through standard blood tests. So why wasn’t it filtered into routine care? Not even in Europe, where guidelines have shown its usefulness for years.
Part of the answer is inertia. For decades, LDL cholesterol has been both a scientific breakthrough and a public health success story. It’s simple, widely understood and directly linked to treatments that work.
“For 50 years, LDL cholesterol was an amazing discovery,” says Snyderman. “It’s not that it’s not a good marker. It’s a good marker.”
Borge Nordestgaard, president of the European Atherosclerosis Society, agrees that LDL cholesterol remains central for a reason. He says, “The evidence is overwhelming; This is beyond discussion.” “Statins reduce heart attacks, strokes, and early death by lowering LDL cholesterol.”
That success helped shape a powerful narrative: LDL is the “bad cholesterol” and reducing it saves lives. But that simplicity has also limited the way we understand risk.
“The result is that patients and physicians know little or nothing about apoB,” says Snyderman.
Recent research suggests that the cholesterol picture is more complex, especially in people who are already taking statins. Previous studies led by Nordestgaard have shown that in treated patients, high levels of apolipoprotein B and non-HDL cholesterol remain associated with an increased risk of heart attack and mortality, while LDL cholesterol is not. ApoB, in particular, emerged as the most accurate marker.
For cardiologist Kaushik Ray of Imperial College London, the challenge is not to choose one marker over another, but to understand what each captures, and what it misses.
“We’re not just interested in cholesterol,” says Ray. “We’re trying to prevent heart attacks and strokes.”
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