“I have Cholesterol” is a common complaint, often causing unwarranted stress and anxiety, particularly among young patients.
When a patient begins the consultation with “I have Cholesterol”, my mind immediately goes back several decades in time to our prep school days, when we sang/shouted, in the dining hall,
I scream
You scream,
We all scream
For Ice cream!
Recalling those childhood memories, I go,
You have Cholesterol
I have Cholesterol
We all have Cholesterol!
The response to my lines is gender based.
Females avoid eye contact and retort in a no-nonsense tone, “I mean I have HIGH Cholesterol, doctor! (Translation: I’m not dumb, you silly man!)
Male patients on the other hand go completely silent as though I had pressed the mute button, (Muwa golu Wuva) and stare back wide-eyed. (What they would really like to say is this: “Just stop talking nonsense doctor, and write me a prescription for some tablets!”)
So, is Cholesterol that bad, after all?
If it had been, during evolution, by natural selection, we would have been extinct by now! Or if you believe in a Creator, why would He want to put such bad stuff in our bodies? (Unless of course he had a cunning plan to buy shares in multinational drug companies that produce Cholesterol lowering Drugs!)
As a matter of fact, folks, Cholesterol is an essential requirement for good health.
Every cell in our body has small amounts of cholesterol, and together with other molecules they prevent cell membranes. (The outer lining of a cell) from being leaky. If a cell membrane is leaky, for example, cells called T lymphocytes, (required for our immune response) will swell up and go POP! and that won’t be nice. While plugging these leaky points, Cholesterol helps maintain the integrity and fluidity of cell membranes, so our cells unlike plant cells do not have a cell wall, allowing them to be more flexible and supple.
And guess which part of our body has the most amount of Cholesterol.
“The liver.” did I hear you whisper?
Nope, not the liver, not muscle, not the heart, It’s our BRAIN! As much as one fifth to a quarter of all the cholesterol in our bodies is in the brain. From birth, until adult life, the brain makes its own cholesterol and all through life from then on, there is a slow turnover of cholesterol throughout life. The brain as you know has billions of cells called neurones, which can make its own cholesterol but it is the supporting cells, called glial cells which are more efficient in synthesising cholesterol and the neurones can make use of this. From the neurones electrical impulses pass along fine filament like processes called axons to communicate with other neurones. These axons are covered by sheaths of Myelin rich in cholesterol (much like the insulation in an electrical wire, but interrupted at regular intervals called “Nodes of Ranvier”) and these cholesterol rich myelin sheaths thus enhance the conduction of electrical signals. Neurones communicate with each other at special junctions called synapses, Electrical signals coming along an axon releases chemical transmitters at the synapse which then activate the next neurone to produce a signal and so on. Recently scientists grew neurones in cultures under experimental conditions and noted they were able to form synapses with each other, but hey were pretty laid back and took their time. Then they added cholesterol to the culture medium and Hey Presto! the neurones started developing synapses faster than Hussein Bolt doing a hundred-meter dash!
“So, what’s the big deal?” I hear you mutter.
Well, boys and girls, the more synapses, better is the communication between nerve cells and this is really important for the developing brain to acquire memory and learning skills.
The blood vessels that are in the brain are lined by tight fitting cells ,forming the so called “blood brain barrier” so cholesterol containing molecules in the blood cannot get into the brain and as we noted before, the brain has to make do manufacturing its own cholesterol for its important functions. Or as Mr. Kipling would have said, Blood cholesterol is blood cholesterol and brain cholesterol is brain cholesterol and never the twain shall mix!
Apart from the brain and nervous system, cholesterol has other important roles.
In the skin it is required for the synthesis of Vitamin D.
The liver uses it as the starting brick to manufacture bile salts, needed to emulsify fats that we eat and help its absorption.
The adrenal gland uses it to make hormones, like Aldosterone which regulates the body’s water content, Cortisol to control inflammation and stress and last but not least, (wait for it — wait for it,) sex hormones like Testosterone and Progesterones. (Aha, NOW I have your attention, don’t I?)
So just imagine life without cholesterol, not enough brain synapses, not enough Testosterone; Life would be deadly dull wouldn’t it?
But there’s always a catch isn’t there?
Too much of a good thing is also bad for us. (Story of our lives, wouldn’t you say? Sigh!).
Cholesterol is a waxy stuff, insoluble in water so it has to hitch a ride with proteins to get to different parts of the body. These molecules are the lipoproteins. Fats that we eat containing cholesterol enter the blood stream as tiny particles called chylomicrons, rich in triglycerides, another kind of fat. The body cells use up the triglycerides as they need for energy production and the remaining particles get back to the liver, where they get recycled as more triglycerides, but if liver is in a bad mood, so to speak, it can turn these returning molecules into cholesterol rich Low Density Lipoproteins, (The “bad” cholesterol we all know). Waxy cholesterol can then get deposited on the inside of our blood vessels and over time, narrow them so that vital organs like the brain and heart are deprived of oxygen and other nutrients. From these plaques little bits may break off and get to these vital organs causing strokes, heart attacks and so on. Sometimes, the plaques become the scaffolding for blood clots to form completely blocking off fairly large blood vessels with catastrophic consequences.
If you treat your liver well on the other hand, it will also produce High Density Lipoproteins (the “good ” cholesterol), which is like an empty garbage truck and collects some of the extra cholesterol lying around and transports it back to the liver.
Clearly then, there are times when lowering Cholesterol levels is desirable. There are two main approaches here.
One is called Secondary Prevention. Here, the strategy is to lower cholesterol in individuals who have already suffered consequences of narrowed blood vessels for example a stroke, heart attack or angina. This is aimed at reducing the chances of further events and death. There is strong evidence from robust randomised controlled trials and meta analysis of these trials that this indeed is the case. In addition, from time to time international cardiac societies put out guidelines indicating to what level cholesterol should be lowered for optimal outcomes and your healthcare provider will guide you.
In the case of Primary Prevention, the goal is to reduce the chances of your getting clogged up blood vessels when you haven’t as yet shown any evidence of it. If this was good for everybody, then we could ask the water board to put cholesterol lowering drugs into our drinking water! Not so, since taking cholesterol lowering drugs also has a downside. Once again, International cardiac societies have developed guidelines where your healthcare provider can calculate your chances of getting an adverse event in the next ten years, called the ten-year cardiovascular risk. Calculated on your age, gender, risk factors for cardiovascular disease like smoking, high blood pressure, diabetes, in addition to your cholesterol levels. Generally speaking, if the risk is over ten percent (not Mr. Ten percent!!) then taking drugs gives you more benefits than risks.
Another area of some controversy is whether individuals over 75 years should be taking cholesterol lowering drugs. The trials mentioned above did not have many people in this age group to make firm conclusions but current recommendations suggest the same approach as in younger individuals.
So young people, I hope, won’t behave like one of my niece in her thirties, who sounded flustered when she rang me saying, “Loku Thathi, I had some pain in the back of my shoulder so I got my cholesterol checked and the report says high!” Why she did the test is a mystery in the first place, but being her Loku Thathi I could afford to be a bit rude and using the slang expression I replied, “Hey! just because the report says high, no need to get your knickers in a twist “! (She has not spoken to me since, but you get the message.)
Now, if you have been thinking, as far as cholesterol is concerned, the lower the better, well, you have another think coming!
Epidemiologists followed up two matched populations, the only difference being that one group had normal cholesterol levels, while the other group had low values. Guess what?
The low cholesterol group actually had a higher all-cause mortality. In other words, the lower cholesterol group had a higher chance of dying from any cause (for example, cancers, infections) compared to the normal group.
The million-dollar question then is this: since we are going to die anyway, does it really matter how we die?
When such a doosra is bowled at us, our Prof. of surgery all those years back taught us how to play it with a straight bat, and we answer.
I don’t know
You don’t know
No one knows!
And that, my friends, is that.
NJ (Consultant physician)
