Forget 'good' and 'bad' cholesterol. The number that actually predicts heart attacks is apoB.

For decades, we've been told to watch LDL ("bad cholesterol") and HDL ("good cholesterol"). Attia argues this framing is dangerously oversimplified. The number that actually predicts cardiovascular risk is apoB — the count of atherogenic (artery-damaging) particles in your blood.

Here's why: each LDL particle carries one apoB protein. But LDL particles come in different sizes. A standard LDL-C test measures the total cholesterol mass inside LDL particles, not the number of particles. You could have low LDL-C but many small, dense particles (high apoB) — which is actually more dangerous. Or high LDL-C with fewer large particles (lower apoB) — which is less concerning.

Think of it like traffic: LDL-C measures total cargo on the road. ApoB counts the number of trucks. More trucks means more chances of a crash into the artery wall, regardless of how much cargo each carries.

Attia's view: apoB should be measured routinely, and for maximum longevity, it should be as low as possible — ideally below the 5th percentile. Atherosclerosis begins in your twenties and accumulates for decades. Early intervention with statins or PCSK9 inhibitors, when appropriate, can prevent plaque buildup before it becomes dangerous.