When LDL (Bad) Cholesterol is Important


Not so bad after all?

A report earlier this week, here, raises questions about the dangers of high LDL cholesterol. Specifically, high levels were found to be protective, completely overturning conventional medical wisdom. Here we present a somewhat deeper dive into the subject.

Both cholesterol, a cell-wall building material, and fat, the most important macronutrient, do not dissolve in blood. Both of these items need to be delivered to the cells, so the ever-versatile liver packages them into little balls with a special coating that allows them to circulate in the blood. The little balls are called VLDL particles, for Very Low Density Lipoprotein. The cholesterol forms the core. Then follows a layer of fat, with, finally, an outer coating of blood-friendly lipoprotein.

Off into the circulation go the VLDL particles, lots of them. Hungry cells that are in the mood for a tasty fat snack will pluck some fat from the VLDL and pull it right into the cell. Within three to four hours, all the fat is picked away, leaving the cholesterol core. At this point, the particle is officially renamed “LDL Cholesterol,” even though it’s the same original particle, minus most of its original fat.

Now it gets interesting. That LDL particle could be dangerous if it got behind an artery wall. If it continues to circulate, it is harmless, and in fact, any cell that happens to need a bit more cholesterol (cells have lots of uses for cholesterol) will actually engulf the whole LDL particle and disassemble it inside.

Any straggling LDL particles that remain in circulation are removed by the liver, or possibly gobbled up by some circulating HDL particles, part of the body’s garbage collection system.

So what about LDL particles that do not get taken out of circulation?

Those which instead find their way behind artery walls are the trouble makers. Cholesterol doesn’t keep very well, and stuck cholesterol soon becomes rancid. White cells show up to immobilize this junk, but if more and more cholesterol particles arrive, the mess just piles up, and atherosclerosis results.

So now we come to the money question: Can this be prevented? The answer is yes, and drugs, like statins, are not the answer.

LDL cholesterol particles come in a variety of sizes. This was largely determined when the liver assembled the things. If the particles are large enough, they TEND NOT TO GET BEHIND ARTERY WALLS. Some of this is genetic. Some people have large particles, and some have small. The small ones are dangerous. But genetics is not the determining factor: particle size is always changeable.

The overall level of LDL particles, which is what is usually measured, is of secondary importance. In fact, this level is tightly regulated by the body for myriad purposes and is best not tampered with.

Particle size can be changed

Almost anyone can alter their LDL cholesterol particle size so that it is large and not dangerous. It is quite a bit harder to change cholesterol level.

Changing particle size is easy, at least in principle. The particle size is determined by circulating fat. More fat—smaller particles. Circulating fat is easily measured. It is called triglycerides and shows up in most blood test panels. This is a key number. If your triglycerides are below 150 mg/dl, it is highly likely that your LDL particles are the large, safe size. If your triglycerides are below 100, it is almost a sure thing. So the triglyceride number is a very important one.

(Statins, interestingly, reduce particle size. Not where we want to head.)

(It is possible to get a blood test that will directly measure particle size. The test costs $50-$100, but is not standardized. Triglyceride measurement, though an indirect indication of particle size, is probably a more reliable way to go.)

At this point you may rightly call foul. We said particle size is controllable, but how do we control triglycerides?

Controlling triglycerides


A triglyceride

Triglycerides are circulating fat. Isn’t it therefore logical, obvious, and common knowledge that eating less fat would lower triglycerides. Well, it is indeed logical, obvious, and common knowledge, but amazingly, it is almost 100% FALSE.

The fat you eat hardly even gets into circulation, and is not the fat that ends up in an LDL cholesterol particle. The fat you eat gets made into another sort of particle called a chylomicron. This particle circulates, is gobbled up in under 10 minutes, and most importantly, contains almost no cholesterol. So low fat diets, or diets that avoid saturated fat, do not reduce circulating triglyceride levels. (In fact, they increase them!) Because the chylomicrons are gone so fast, they don’t show up in blood tests at all, especially if there was a 12 hour fast in advance of the test. The triglycerides that are measured in the blood test are the ones that were packaged with the LDL and VLDL particles.

So where did the triglycerides that were packaged with the LDL and VLDL particles come from?

The triglyceride level is mainly determined by circulating glucose—sugar. If glucose is high (which is all too common in the Western diet, insulin will be high. If insulin is high, it is a signal for cells to eat glucose. These cells are, at the same time, forbidden to eat circulating fat. Both the excess fat, and the excess glucose, if any, will be stored as fat, or will circulate as fatty acids.

Glucose is sugar. Fructose is converted to glucose by the liver. Starches are converted to 100% glucose in the intestines. Triglyceride control is all about glucose. Alcohol will also raise triglycerides.

Here is the protocol. It is simple. Measure triglycerides. If the level is over 150 mg/dl, cut out some amount of booze, starch, sugar, and fructose. How much? It varies from person to persons. For some, it’s 100%. Others needn’t cut at all. Cut, and wait a month or two, then re-measure. If it is under 150 (or better, under 100), stay the course. If it is still too high, cut some more. Eventually it will come down. It is extremely important to get this number under control. Besides greatly reducing the risk of heart disease, it will reverse adult onset diabetes as well.

Maintain triglycerides at the lower level, for the rest of your life, of course, and you can probably forget about LDL (bad) cholesterol levels. More on triglycerides here.

A couple of loose ends

Why do low triglycerides force the large, safe particle size? The liver is going to make and circulate the same amount of cholesterol (unless some drug interferes with it). It packages this fixed amount of cholesterol, along with triglycerides, into the VLDL particles. If there is less triglyceride material available, it is forced to allocate the cholesterol in fewer, and hence larger, particles.



Why are larger LDL particles safe? Most atherosclerosis comes about from leaks during arterial wall repair. A dead artery wall cell is replaced in about 30 minutes. During that time, it is covered with a somewhat leaky mesh of platelets. That mesh will keep out the larger LDL particles, but not the smaller.More on arterial health here.

  1 comment for “When LDL (Bad) Cholesterol is Important

  1. Nancy T
    June 24, 2016 at 8:55 am

    Would love a more indepth article about alcohol’s effect on blood pressure, blood glucose and triglycerides. Searched your site and didn’t see one. You mention in almost every article that alcohol is bad, but would love more indepth explanation of how it works.

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