Thursday, 20 May 2010
What's This Cholesterol Thingy Then ?
There is so much twaddle talked about its level in the blood, that it would be useful to explode a few myths and get things into some sort of proportion. First of all; you cannot have a cholesterol level. Absolutely not, Nada, zilch, zero. What you are being told, and you need to bear with me here; is your overall plasma lipoproteins level. In other words, the sum total of your, HDL, IDL, VLDL and LDL. Oh and they might add in the largest molecule in the lipoprotein family as well, the chylomicron. So first myth; cholesterol level is in fact, nothing of the sort. You will also find in the bewildering world of cholesterol that nothing is called what it is, and that's by so-called scientists!
Lipoproteins are the means of conveyance of numerous nutrients around the body that are not soluble, such as (hushed tone) fat and cholesterol, and no, fat is not cholesterol, it's fat. Others that are water soluble can be carried in the blood without this need, but fat soluble vitamins, hormones etc have to have a means of transport and generally speaking that's a lipoprotein. There are quite a few other divisions in this category, but no-one will measure them or likely have any clue what they are, especially your doctor. You will have your LDL and HDL measured also and these will be called 'bad' and 'good' cholesterol respectively, even though they are nothing of the sort and HDL, so called 'good', has in fact the largest amount of cholesterol contained within, than any other lipoprotein in the human circulatory system. Confusing isn't it? And we are only just getting started!
OK, wake up at the back! We are moving on. Second of all, now I've told you what the test is really measuring, I have to say that any measurement of these myriad 'transporters', is and of itself, not that accurate. It's usually an approximation and is not really something that a whole industry should be founded upon, to moderate, but nonetheless it has been. So moving swiftly on, these little packets of fat soluble items are being transported around the body but why? Well as you eat, your gut, (general name for intestines), removes the proteins, fats, vitamins and minerals, that is in your food and then they are sent to keep you alive. Your gut makes the largest lipoprotien, chylomicron, and that then transports the fat consumed (now called a triglyceride) and some cholesterol (not a lot), to the adipose tissue for storage
Sorry but it gets complicated now. Both your gut and liver also make a molecule called a very low density lipoprotein-VLDL. This also transports fat and as it transfers it to tissue it shrinks, and becomes the low density lipoprotein (LDL), we all call 'bad'. Well I don't because I cannot attribute any behaviour pattern to a molecule, but still, moving on. Oh sorry, I missed out on the IDL (intermediate etc etc) which is what it's called, before it gets small enough to become LDL. I've added a diagram, which may help.
We now get to HDL or high density lipoprotein, or the good guy at the feast. There has to a feast doesn't there? Well HDL is made in the liver, well mainly, er probably, well we're not really sure.... yet. It is alleged that HDL sucks up cholesterol from plaques in the arteries thus making it all better, so if you have lots more of it say more than 2.0 mmol/L then you're going to live forever! Yippee! Even though we don't really know quite how it's made, or how it achieves this miracle vacuum cleaner act on cholesterol, we can set a level which is good or bad. Talk about building a hypothesis on a dream, of an idea, of a thought while you were on the loo' one day. It's all complete and utter Tosh! You can't state that a molecule can cross both ways through a concentration slope, it defies the laws of well, just about everything in Biology, but what the hell, lets not the truth get in the way of good story, and this reads pretty much like a fairy tale. Shame it's such a dangerous one!
So here we are then, you all know exactly what cholesterol is or actually what it isn't, but what the medics or more importantly Big Pharma, call it, outwith what it actually, scientifically is! How any Doctor can peddle this nonsense with a straight face I know not but, sadly they do. So, now we have established what one may be tested for and more importantly what it actually is, rather than the nomenclature that has been attributed to it, for reasons I cannot explain with any conviction, except stupidity or an over weaning need to treat people as idiots, that does seem to pervade the medical profession. "You don't need to understand your condition Mrs Smith, just take my word for it, it's essential for you to take these pills to lower your cholesterol".
Next important fact is that you will be told that eating any form of saturated fat, is the reason your level of cholesterol is high especially your LDL. LDL isn't cholesterol and fat isn't it either. What you now need to know is that diet, will not substantially make any difference to the levels of cholesterol in your body, because any deficiency in your diet will be made up by your own system (what treachery, from our own bodies!). So your liver, in fact all your cells, except neurones, will just crank up the volume and produce more of the stuff to cover the deficit. 'Quantitive easing' for cholesterol.
So then, cholesterol is hard to lower, in fact almost impossible unless we interrupt its manufacture at cellular level but why on earth would we want to do this? It is important for most processes and those people who have extremely low levels suffer from serious disorders that can often be fatal. To illustrate this I would cite Smith-Lemli-Opitz Syndrome. Lets call it SLOS for the sake of space. Details of this are here. As you will see it's pretty awful and is largely due to an inability to synthesise cholesterol. Not so sure about lowering now, I bet.
So eating fat will not lower, raise or otherwise alter your cholesterol. And one aside, whilst I'm here; when your body decides it needs to access your stores of energy in the adipose tissue (body fat) it has stored as triglyceride it distributes them in lipoproteins, and what sort of fat is triglyceride; yes it's a saturated one. The molecule is fully saturated with hydrogen atoms without any double bonds so it is straight, as are all in nature. So your own body only produces saturated fats. The liver then picks up the glycerol and combines two molecules to form glucose and the fat goes to the muscles for energy use.
The liver is in fact the most amazing biochemical factory there is. It constantly changes, stores, reforms and manufactures most of the molecules we use in our bodies every moment in our lives and cholesterol is just one. But because it is present in virtually very cell and is needed for numerous functions we lower it, I believe at our peril. Peril of quite a few dangers to our well being. In my next diatribe I will outline how the myth attached to this evil substance, has brought about the rise and rise of the 'statin' or HMG-CoA Reductase Inhibitor and what it can do to your well being for little to no reward.