Does LDL Particle Size Really Matter?
Updated: Mar 15, 2022
In previous blogs I have written about how LDL is very beneficial to the body, how low levels of it can be dangerous, and how it is not causative in the atherosclerotic process. One argument I often hear is that while the LDL particle itself is not causative in atherosclerosis, when it becomes damaged it does become causative. The thinking here is that a normal undamaged LDL is very healthy and just does its job of delivering cholesterol and other nutrients to the body tissues. However, when those particles become damaged through oxidative stress, all of the sudden the LDL molecules become causative in atherosclerosis. Let’s investigate that a bit.
One way of measuring damage to LDL particles is by measuring their size. There are various lipoproteins that all have different sizes. In order from largest to smallest they are the chylomicron, the VLDL, the IDL, the LDL, and the HDL. Since the LDL is so focused on when it comes to atherosclerosis, we have developed ways to measure the various sizes of the LDL particles. When LDL particles get damaged, they seem to get smaller and this is often said to be a risk factor for atherosclerosis. (1) It is thought that as they get smaller, from this damage, their smaller size allows them to squeeze in between the endothelial lining and make their way into the arterial wall. Below are images of test results of an LDL particle size test. One shows what it would look like if the LDL particles were undamaged and normal size and the other shows what it would look like with damaged LDL particles getting smaller.
You can see that the smaller the LDL particle size the more red shows up on the chart.
Now, I don’t necessarily buy the idea that a smaller LDL particle is able to infiltrate the endothelium and take up residence in the arterial wall. First off, if the fact that it was smaller is what allows it to do this, then why is it that HDL, the smallest of all the lipoproteins, doesn’t do this as well? That is just a logical question that places doubt in the idea, but there is one scientific phenomenon that draws into question the idea that smaller LDL particles can penetrate the arterial lining better.
This is the phenomenon of what is called 4th phase water. I discuss this in my previous post on why we don’t see atherosclerosis in veins, but I will review it briefly here. Water has properties unlike other liquids. When placed next to a hydrophilic surface, like the inner lining of the artery, water structures itself into what is called 4th phase water, or exclusion zone (EZ) water. (2) Since the blood is nearly half water, this happens on the inner lining of the artery. This exclusion zone water has the consistency of a gel. It is called EZ water because it does just that, it excludes almost everything that isn’t it, it acts as a barrier. (3)
Because of this, if we have healthy EZ water in our arteries they protect the arteries and preserve the function of the endothelium. Radiant energy, of which one form is infrared light, has been shown to help build and maintain EZ water on hydrophilic surfaces. (4) This is why studies using infrared sauna have been shown to boost endothelial function. (5,6,7,8)
In his book on 4th phase water, Dr. Gerald Pollack notes that even the smallest protein found in the blood stream, albumin, cannot penetrate the EZ water. The protein albumin is 3.8 nanometers in diameter. EZ water is created in such a way, the planer sheets are slightly offset, that this small molecule cannot penetrate the barrier it creates if it is intact and healthy EZ water.