The Lipid Profile

Cholesterol is a term we hear all too often, given our beliefs in the ‘low-fat’ propaganda. Let’s have a closer look and improve our understanding of lipids (fats) and The Lipid Profile – the blood cholesterol check up that we have to undergo regularly. Some of the terms used in medical literature and in our reports need a better understanding.

Fats have many vital roles in the body. So much so, that no fats means no life. Fats (1) form the outer membrane of every cell in the body. (2) They are a compact dense source of energy. (3) They provide us with fat soluble vitamins, and are a part of the bile acids & several hormones within the body. (4) The liver creates most of the fats circulating within the body and dietary fats have little say in the matter.

Our blood is made up mostly of water. As you all know oils (fats) and water do not mix very well. So our fats (lipids) are transported within special carriers known as lipoproteins. Most of the fats that they carry are in the form of cholesterols or (TG) triglycerides. The lipoprotein outer membranes are made up of phospholipids – phosphate on the outside, and lipids on the inside. These can then freely mix in blood and go on in their buoyant way doing their duty of distributing fats to our cells. The density of the proteins in the lipoprotein carriers decides its name – HDL (High Density Lipoprotein), LDL (Low Density Lipoprotein) & vLDL (Very Low Density Lipoprotein).

When labs assess our blood for the lipids, they give us what is known as our Lipid Profile. These reports inform us of – Total Cholesterol (TC), HDL, LDL, vLDL, TG and the ratios TC/HDL & LDL/HDL. Actually the tests "are supposed to" measure the amount of cholesterol within each type of carrier. But they don't. Much of this science is assumptive and very outdated. The only actual assays (measurements) that they carry out are for the TC, HDL & TG. The rest is all guess work.

Decades ago, Dr. Friedewald found that each particle of vLDL carries typically 5 TG molecules within it. Using that information the vLDL is determined by TG/5. Then the LDL is calculated thus LDL = TC - (HDL + vLDL). Two out of 5 of the components within the report are calculated based on assumptions . Improvements in technology have resulted in newer labs giving us the direct measurement of cholesterol contained within the lipoproteins. In which case, “direct” is added to the type of the lipoprotein in the test report. 

In all of the above it is the cholesterol within the lipoproteins (example LDL-C) that is being reported, not the particle numbers (LDL-P) of the lipoproteins itself. There is no doubt that the sterols entering the artery walls and being internalized by macrophages cause atherosclerosis or plaque. But latest developments in the field have shown that it is the lipoprotein particle number and the size which is of critical importance. It is only the smaller and denser particles that can penetrate the arteries. The larger buoyant particles are largely benign & harmless.

The lipid trafficking in the body takes place within several lipoproteins, namely (from large to small) Chylomicrons, vLDLs, IDLs (Intermediate), LDLs and the HDLs. The HDLs are the reverse transporters of the lipids (back to the liver) and therefore supposed to be the good guys. Chylomicrons are used to transport lipids from the digestive tract directly through the lymph and have a very short life of a couple of hours, by which time they have delivered their stuff. The other lipoproteins wear out in order of their size after delivery of their goods. The LDLs live for about 3-1/2 days and form the predominant part of the TC that the lab reports. Therefore they are supposed to be the bad guys. It must be noted that among all health parameters, the lipids fluctuate the most and pretty fast. So they could be affected widely, by a lot of variables.

Newer studies have identified 4 different sizes of the LDL and as mentioned, it is the smaller denser variety that could cause harm. Hopefully in sometime this technology will also be available in India and we would benefit from better details. The ultracentrifugation technique known as the VAP profile is now probably available with Metropolis. The NMR (Nuclear magnetic resonance) spectroscopy is still a distant dream. But until then, I guess we’ll keep blaming all the fats equally.

If you are in Nutritional Ketosis and 'burning' fats for energy, you are bound to have higher fats in circulation. At least for some time. However, the tell tale sign of having the larger buoyant harmless LdL is that your TG levels will drop and your HdL values will go up. According to many prominent cardiologists, the TG/HdL ratio is a much more important cardiac disease risk marker. And the advice is to keep this under 2.0. Any value over 3.0 is of concern and the sooner this is brought down, the better. Unfortunately most doctors do not know of this, don't look at this, and none of the labs give you this ratio. So much so for the standard Lipid Profile.

Using my favourite tool, the analogy, let's look at lipids in a more common sense sort of manner. Let's equate Cardio Vascular Disease with Pollution in a city. Pollution as we all know is caused by the number of vehicles on the road. More specifically, the number of ill maintained polluting vehicles. Any child can tell you, that the number of passengers in the different types of vehicles is not the cause of the pollution. Similarly our cholesterol (passengers) carrying vehicles (lipoproteins) are the reason for CVD, IF, they are polluting (oxidized) and not the cholesterol content per se. Simple to understand, isn't it ?