As we get older (and we all, for the most part, do), we tend to worry most about diseases like cancer and Alzheimer’s. Understandably so. But what people often forget is that heart attacks are still the biggest killers in the U.S. and in the whole industrial West. But here’s the thing. Unlike those other lethal diseases, cardiovascular disease, or atherosclerosis, shouldn’t be that difficult to prevent or combat. The fatty plaques that can develop in your arteries usually take decades to grow into life-threatening terrors. We know we can stop this progression, especially of early-stage disease, and, in some cases, even reverse it, with the right diet and physical activity and, when necessary, cholesterol-lowering drugs. 

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But what we really want to do is to be able to find out whether you’re at elevated risk for heart disease before there’s any visible plaque formation. To do that, at your next physical, your doctor will almost certainly test your LDL and HDL cholesterol levels. LDL is the cardiac risk factor here -- generally speaking, the higher the levels, the greater the chance the cholesterol inside your coronary arteries develops into plaque. But what your internist most likely won’t do – that is, not unless you specifically ask –  is to order up another test, the ApoB, which many cardiologists now agree is the single most valuable blood test when it comes to predicting future heart attacks. Not getting it – your insurance probably won’t cover it but it’s not expensive, under $100 – is, in my view, simply a missed opportunity to potentially save your life. Here’s what you need to know about the apoB test, why you must ask for it, and how it can safeguard your heart health, and your life. 

So, what is ApoB and how is it different from cholesterol?

Although we sometime use a loose shorthand to describe LDL as “bad cholesterol” and HDL as “good,” the reality is, cholesterol itself isn’t bad – it’s an essential lipid that the body uses, for instance, to make cell membranes and sex hormones, and our body produces more of it than we consume in our diet. (Afraid of high-cholesterol foods like eggs or shellfish?; don’t be.) But cholesterol, being a lipid, isn’t soluble in water, the way glucose and sodium are. So, each cholesterol particle travels the bloodstream inside a little protein container – think of it as a kind of cargo ship. The whole thing is called a lipoprotein, or, protein on the outside, cholesterol on the inside. Now, here is where “good” and “bad” really mean something. LDL (or low-density lipoprotein), and a couple other potentially dangerous particles, only travel in cargo ships that are covered in a molecule called Apolipoprotein B or ApoB. HDL rides with ships covered in Apolipoprotein A, or Apo A. Who cares, right? Well, you should. Riding in style with apoA, HDL can pass more easily in and out your coronary arteries, which allows them to move excess cholesterol out. The ApoB particles that cradle the LDL cholesterol have a tendency to get stuck inside the lining of the artery, the endothelium -- the first domino to fall in what could wind up becoming coronary artery disease. 

How is the ApoB test different from the standard LDL test? 

While the LDL test gives you an idea (the standard test is only an indirect measure of LDL, for what it’s worth) of how much LDL is circulating in the bloodstream, in other words, how much cargo those lipoprotein ships are carrying, what’s more important is the number of the ships – the apoB particles. The more ships inside the arteries, the more havoc is created, the more likely that LDL gets lodged inside the artery walls. There it becomes oxidized by free radicals, in other words, armed to do real damage. And this shipwrecked LDL attracts more LDL. If the body can’t successfully remove it, the immune system gets into the act which sometimes just further gums up the works. The end result is plaque which, if left unchecked, can slowly, steadily grow, until it begins to choke off the heart’s blood supply or, until the protective cap that covers it breaks off and blocks the artery, causing a heart attack. 

How is the ApoB test a better risk measure than LDL? 

There is nothing wrong with the standard LDL test –a large body of research correlates high LDL with an increased risk of heart attack. And because one LDL particle travels with one ApoB particle, the LDL number can often give you a reasonably good idea of how many ApoBs are circulating. But if you’re overweight or have metabolic syndrome or type 2 diabetes, that rough-and-ready correlation between LDL and ApoB begins to fall apart. The LDL particles are often extra-small, and more dangerous, in a way that the standard LDL test doesn’t capture. In other words, for people whose underlying conditions put them at higher risk for heart attack, who most need a reliable blood test to gauge that risk, the LDL test can fail them. For them, and for my money, for most anyone, I recommend adding the ApoB test to your next annual physical. Maybe the standard cholesterol test suggests you’re at low risk for the next, say, five years. But you want the best assurance you can get that the risk stays low over the course of your entire life. A little more info could make a lot of difference. 

What do the ApoB test numbers mean? 

The standard guidance from the National Lipid Association is that a test number of less than 80 mg/dl puts you in the moderate heart attack risk category. That’s OK but driving that number below 60 would be that much better if you already have heart disease, and especially if you have plaque in your heart vessels. So, if you’ve got underlying cardiac risk factors, like high blood pressure, high blood sugar or a concerning family history, I and many proactive preventive cardiologists, advise trying to do just that. If you’ve got any indication that your cardiovascular or metabolic health may be trending in the wrong direction, I encourage you to work with an integrative physician or preventive cardiologist, to set up an ApoB goal and come up with a plan to reach it.  

So, my numbers aren’t great – what now? 

The good news is that the same things that safeguard your overall health work to get those ApoB numbers, and LDL numbers, where you want them to be. It should go without saying that smoking and drinking more than moderate amounts of alcohol – as you may well know, I actually prefer no alcohol – are off the table. Regular physical activity is key – that could be lots of movement throughout the day, capped with gym workout or frequent long walks, really its up to you. 

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My diet prescription should come as no surprise to my regular readers. High calorie/low-fiber carbs, especially processed foods, are bad news. Keep the sugar intake down as low as possible. On the “to do” side of the ledger are foods high in healthy fats like the omega 3s, ditto high-fiber plant protein (especially nuts and seeds) with, for non-vegan/vegetarians, some clean animal protein from healthy sources. A diet rich in non-starchy veggies should help supply a protective dose of vitamins, minerals and micronutrients. Make sure you’re getting enough vitamins D and C and, thinking minerals, magnesium and potassium. 

What about cholesterol-lowering drugs 

Not only can the ApoB test be the red flag that motivates your lifestyle upgrades but it’s also a way to monitor your progress, to see how much you’re moving the ApoB needle. If, despite your best efforts, the numbers are still concerning, then you and your physician will probably want to have a conversation about cholesterol-lowering drugs.