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To understand apolipoprotein B, it’s important to first understand how cholesterol moves through the body.Cholesterol, all by itself, cannot float through the blood. Cholesterol is important for many body functions and it needs to be carried through the blood stream so it can be used for energy and to make hormones such as vitamin D. Cholesterol does not mix with blood. It must be carried through the bloodstream by transporters called lipoproteins.
Cholesterol, all by itself, cannot float through the blood. Cholesterol is important for many body functions and it needs to be carried through the blood stream so it can be used for energy and to make hormones such as vitamin D. Cholesterol does not mix with blood. It must be carried through the bloodstream by transporters called lipoproteins.
Lipoproteins got their name because they are made up of fats (lipids), such as cholesterol and triglycerides, and proteins.
ApoBs are proteins found in lipoprotein particles that can lead to plaque in the wall of arteries.
The apoB-containing lipoprotein particles that are the most damaging to our arteries include not only LDL cholesterol but also remnants of chylomicrons and VLDL (very low density lipoproteins). All three– LDL, VLDL, and chylomicrons – promote atherosclerosis.
Atherosclerosis is a disease caused in large part by the build-up of excess cholesterol within the artery wall, which leads to cholesterol-rich deposits called plaque. When a plaque bursts or ruptures, blood clots form. They’re dangerous because they can block blood flow to vital organs like the heart and brain.
Atherosclerosis, therefore, is the underlying disease process that leads to nearly all heart attacks and most strokes.
Now, let’s get back to apoB.
Since each apoB-containing lipoprotein particle has one apoB molecule, measuring apoB levels in blood gives us a good approximation of the total number of atherogenic lipoproteins in the blood. The greater the number, the greater the risk of plaque build up from inflammation and oxidation of these higher risk particles, in the long term, the greater the risk of a heart attack.”
In fact, research has shown that apoB is a better predictor of cardiovascular disease than LDL cholesterol. It is far better than cholesterol measurements. In fact, in our opinion, we are not so sure cholesterol levels matter much at all.
Keep in mind, too, that there are two types of apoB. Both are bad news for our arteries. One type is made in the intestines. It’s called apoB-48, and its lipoprotein partner is chylomicrons. Another type is made in the liver. It’s called apoB-100. Its partners are primarily LDL and VLDL.
Lifestyle first. One of the most important ways to start to reduce Apo B is to reduce intake of sugar and bad fats (trans fats). Sugar and simple carbohydrates drive up Apo B levels and the number of small dense LDL. (Sd LDL is a topic for another article) The key is first determining why Apo B is high. That requires looking for the root cause. This could be another metabolic problem, hypothyroidism for example, or insulin resistance, prediabetes or possibly genetic factors that make it difficult for the body to clear the Apo B containing particles. It could even be high because of factors that lead to an increased state of inflammation or oxidation or even something to do with how healthy our intestinal tract is. Yes, even the microbiome, the bacteria that line our intestine, may be one of the root causes of these high risk number of apo B particles.
The only other source of cholesterol in fasting blood is found in HDL particles. HDL’s lipoprotein partner is not apoB. It is apoA and other proteins.
“That’s critical to know because as far as your arteries are concerned, it is only apoB-containing lipoproteins that are always ‘bad,’”…. “ApoA- and HDL-containing lipoproteins can be ‘good’ or ‘bad.’” That is a complex topic for another discussion. The function of the HDL particle is more important that the number. Apo A1 proteins are found on HDL particles but there can be more than one per particle so not a one to one relationship like Apo B.
But wait, we can hear you wondering: “Isn’t HDL always the ‘good’ cholesterol?”
Unlike ApoB, HDL has both a good and bad side.
Not always. “We once thought HDLs were always ‘good,’ and the more HDL cholesterol in the blood, the better. But we now know that HDLs can go ‘bad’ and lose their ability to reduce inflammation and remove cholesterol from the artery wald.”
Recent research3 by cardiologist Stanley Hazen, MD, and colleagues from the Cleveland Clinic have documented this Jekyll and Hyde nature of HDL.
Bottom Line: There is HDL that is functioning well and doing good things for our arteries, but there is also HDL that is dysfunctional.
Researchers at UCLA have reported4 on the effectiveness of a heart-healthy lifestyle in repairing HDL. The scientists, led by James Barnard, PhD, and Christian Roberts, PhD, obtained blood samples of men ages 46 to 77 attending a three-week program of healthy eating and exercise at a Longevity Center.
On entry, the men tended to have dysfunctional, pro-inflammatory HDL. But blood tests after three weeks showed that HDL had converted from pro-inflammatory to anti-inflammatory, from bad to good.
So where do we go from here?
Standard lipid blood testing is not sophisticated enough, at least not yet, to tease apart HDL particles and isolate the good HDL from the bad.
But with standard testing, doctors are able to do something that’s very helpful. They can approximate our total amount of apoB-containing lipoproteins (yes, the always bad ones).
They do so by looking at the non-HDL cholesterol number that is now on many standard blood panels. Non-HDL is all the cholesterol in the bloodstream except HDL, which means it’s all the bad apoBs, not just the LDL apoBs.
By paying close attention to our non-HDL cholesterol, a window into our apoBs, physicians hope to better predict the risk of atherosclerotic plaque growth and heart attacks.
Here is the formula for determining your non-HDL:
Non-HDL cholesterol = Total cholesterol minus HDL cholesterol.
So if your total cholesterol is 190 mg/dL and your HDL cholesterol is 40 mg/dL, your non-HDL cholesterol is 150.
The physicians and dietitians recommend that non-HDL be no more than 120 for prevention and no more than 100 for the halting or reversal of plaque build-up in those with established atherosclerosis or those at very high risk, such as people with diabetes.
Usually, an apoB of less than 100 mg/dL is considered desirable in low-risk individuals.
Less than 60-80 mg/dL is desirable in high-risk individuals, such as those with cardiovascular disease or diabetes.
ApoB numbers are rarely included in standard lipid blood tests. You may need to request Apo B.
Generally, the same lifestyle measures that lower LDL cholesterol will lower apoB. A mix of interval cardio and strength or resistance training always advised. Working out with a friend increases likelihood you will stick to the program. Consider some of the health aps like my fitness pal to keep track of your efforts.
All the above dietary, exercise, and other lifestyle actions are proven in several studies to significantly lower non-HDL, and therefore apoB-containing lipoproteins.
With healthy living, in effect, you’re landing a one-two punch. You’re wiping out the bad apoB-containing lipoproteins and the bad HDL.