Testing for ‘Bad Cholesterol’ Doesn’t Tell the Whole Story

For decades, LDL cholesterol has been the standard for assessing heart disease risk, guiding treatments like statins that lower its levels to reduce heart attacks and strokes. However, LDL tests only measure cholesterol content in particles, not the number of particles themselves—meaning two people with identical LDL levels may have vastly different risks. Apolipoprotein B (apoB), which tracks the total number of cholesterol-carrying particles, has emerged as a more precise predictor of risk, according to growing research. In March 2026, the American Heart Association and American College of Cardiology acknowledged apoB’s superiority in updated guidelines but stopped short of endorsing it as the primary testing method. A 2026 JAMA study analyzing 250,000 U.S. adults found apoB-guided statin treatment could prevent more heart attacks and strokes than current LDL-based approaches while remaining cost-effective. Despite this, apoB testing remains rare in routine care, even in Europe, where guidelines have long recognized its value. Allan Sniderman, a cardiologist at McGill University and lead author of the JAMA study, argues that LDL’s dominance stems from decades of public health success and simplicity. ‘For 50 years, LDL cholesterol was an amazing discovery,’ he says, noting its proven link to statin effectiveness. However, recent studies show that in patients already on statins, high apoB levels remain strongly tied to heart attack risk, whereas LDL does not. Børge Nordestgaard, president of the European Atherosclerosis Society, agrees LDL’s evidence is ‘beyond discussion’ but acknowledges apoB’s growing relevance in refining risk assessment. The inertia around apoB testing reflects broader challenges in shifting clinical practice. LDL’s ‘bad cholesterol’ narrative has been deeply ingrained, leaving many patients and physicians unaware of apoB’s potential. Yet, with statins failing to fully address residual risks in treated patients, experts like Sniderman and Nordestgaard emphasize the need for broader adoption of apoB testing to improve precision in heart disease prevention. Standard blood tests can measure apoB, but widespread implementation has yet to occur.