The Most Important Cholesterol Number to Know Is Probably One Your Doctor Doesn’t Test For

When doctors interpret our cholesterol readings for us, they usually give us a cholesterol levels chart, specifying healthy cholesterol levels by age and risk status. There may be an LDL cholesterol levels chart, or an HDL cholesterol levels chart, or maybe some combination cholesterol numbers chart by which we can measure our progress.

But the cholesterol numbers that really count usually aren’t on the chart. In fact, they usually aren’t even tested.

We are usually told that LDL cholesterol is always bad, but the simple fact is, LDL cholesterol isn’t even measured in most lab tests. Medical laboratories estimate LDL cholesterol as by measuring total cholesterol, HDL cholesterol, and triglycerides, and then making LDL 20 per cent of anything that’s left. The problem is, if you start cutting your calories and getting exercise, sending your triglycerides down, then the “guestimate” of your LDL will go up.

It is possible, however, to run a separate LDL cholesterol test for about $500. But even that doesn’t yield the most useful number.

LDL cholesterol comes in two forms. One form of LDL, attached to a protein called apo-A, is fluffier, fresher, and less prone to attack by free radicals. The other form of LDL, attached to a protein called apo-B, is denser, older, and subject to oxidation. It’s the process of oxidation that actually leads to the formation of cholesterol plaques inside the linings of artery walls.

You can have “healthy” total LDL levels and high levels of apo-B, and you are actually at increased risk of cardiovascular disease. You can have “high” LDL with low levels of apo-B, and you actually don’t need cholesterol medication. So why don’t doctors measure the cholesterol number that really counts?

The simple reason is, the medical industry has invested far too much in products for lowering cholesterol numbers that don’t actually make any difference. After 50 years of telling the public that total cholesterol, and then LDL cholesterol, was the culprit behind heart attacks and strokes, many industry leaders in the USA are loathe to tell the public that doctors don’t measure the numbers that count and drugs don’t treat the numbers that count. But European doctors are increasingly switching over to the measurement of the ratio of apoB100 to apo-A1 as the single number that tells it all for high cholesterol.

Prediction of the risk of stroke, incidentally, turns out to have at least as much to do with blood sugar levels and kidney function, so the ratio of apoB100 to apo-A1 is of greatest value for predicting risk of heart disease. Testing apo-A and apo-B does not require you to fast, and it isn’t affected by triglyceride levels. But if you really want to know if you need to take a drug to change your cholesterol levels, get the right test, which is for apoB100 and apo-A1.