Why Doesn't the State of Having High Blood Cholesterol Cause Pain?

Progress in the sciences is as much a matter of finding novel questions to ask as it is a matter of answering existing questions. The novel question here is this: given that high blood cholesterol is harmful over the long term, accelerating the progression towards atherosclerosis, so why haven't we evolved to feel pain and discomfort from being in that state, leading to avoidance? The answer is mostly likely that issues that arise in later life, after reproduction is carried out, are not subject to selection pressure to anywhere near the degree needed to improve the situation for the individual. Evolution optimizes for early life success and reproduction.

To avoid any kind of potential harm to the body, to restore physiological functions when out of balance, and to satisfy the biochemical needs of the organism by giving itself signals that favour respective behaviour. Acknowledging this, one may ask why causal drivers of cardiovascular disease do not prompt the individual to behave in a way that diminishes these risk factors. Why does the insult to the vascular endothelium by smoking, high blood pressure, or high blood sugar not cause discomfort? Why does the vasculature of a person with familial hypercholesterolemia not hurt? Why does a person with high cholesterol not feel antipathy for fatty and high-caloric meals?

From an evolutionary perspective, the mentioned physiological functions preserve the integrity of the body with the ultimate goal to enable the organism to reproduce. Physical harms and unsatisfied physiological needs directly affect the probability of reproductive success and therefore, individuals displaying favourable behaviour in this regard are more likely to pass their genes on to the next generation. Any genetic trait with effects that become relevant only after reproduction does not exert pressure to be sustained. Such traits may even have been beneficial under the circumstances of feast-famine cycles under which they evolved. This explanation why detrimental genetic traits leading to hypercholesterolemia, diabetes mellitus, and obesity, occur with such high prevalence has been called "thrifty gene hypothesis".

Hypercholesterolemia affects one in two individuals in Western societies and is, relying on different lines of evidence, causal for the development of atherosclerotic cardiovascular disease. Genetic traits that favour high blood levels of cholesterol have likely been beneficial long ago to foster energy security and in consequence, lead to early reproduction. It is indisputable that cholesterol is an essential element of the human body, but with 93% of all cholesterol being intracellular and famine episodes being virtually absent today, do we than still need any cholesterol in our bloodstream? Very low levels of LDL cholesterol, due to mutations or aggressive medical treatment, do not appear to have any detrimental effects.

While the question why hypercholesterolemia does not hurt may primarily be of academic interest, the answer provided may be useful for patient care as well. It can explain why cholesterol levels referred to as "normal" by patients and physicians is still associated with subclinical atherosclerosis as precursor of established cardiovascular disease and should be a target of treatment. Since high cholesterol does not hurt, lipid lowering will not confer symptomatic benefit. Therefore, patient discussion - including the principles discussed here - is the key to medication adherence.

Link: https://doi.org/10.18632/aging.102620

Comments

Good question, I've never asked myself. But how could an individual feel such pain. Could inside of the blood vessels develop in that way that I felt pain?

Posted by: thomas.a at December 23rd, 2019 6:19 AM

There are a lot of harmful things that cause no pain. High-blood sugar. In fact, if feels good. Hi blood pressure. Minor to medium liver damage also can come without pain. The whole brain, some parts of the intestines, and many others. I think the pain is needed for an immediate and obvious reaction like moving away or stopping doing what causes pain. If there is no obvious action to be taken for the pain it is kinda useless. From this point of view it amazes me that we feel so much pain for internal damage. Passing a kidney stone is quite painful. I guess in the whiled if you get an immediate kidney damage it usually has to come from a claw/fang... A bit too late to react ...

Posted by: cuberat at December 23rd, 2019 7:31 AM

The thinking is that long term action (ex. eating unhealthy dont give short term pain as a warning. Maybe future human evolution will go in that direction if possible.

Posted by: thomas.a at December 23rd, 2019 10:42 AM

Yea, a lot of slowly progressing conditions are painless. So far from unique.

Posted by: JohnD at December 23rd, 2019 11:48 AM

Hi there! Just a 2 cents. MerryXmas&aHappyNewY (XY chromosome),

''Why does the insult to the vascular endothelium by smoking, high blood pressure, or high blood sugar not cause discomfort? Why does the vasculature of a person with familial hypercholesterolemia not hurt? Why does a person with high cholesterol not feel antipathy for fatty and high-caloric meals? ''

It depends on many factors, previous health state (early/-lier life), if you do any exercice or none at all and sit on a chair allday long; to say that having high blood cholesterol causes no pain; is because you have not entered yet into the atherosclerosis state. Thus, your blood/oxygenation is correct, so far, in your blood vasculature...but it is (you are) a ticking time bomb (waiting to explode at - any - moment soon). It is insidious because there is no real pain before that happens so 'you think' you are healthy enough, but your HDL:LDL levels tell otherwise. I was thin, always (below 150lbs), and it came to me even so (because I inherited family hypecholesteremia from great-great....grand parent somehow). My twin sister did not obtain it, I did (being a twin, makes for comparison to see if we suffer same things). But, she did say she had bouts of high cholesterol too (and she was always very-thin.. below 120lbs). Never obese once. Of course, I did contribute to it by splurging in crap/Junk food For Many Years...and that took its toll, for sure the most. My body told me - No - for 'extra cholesterol/fatty foods'...anymore when I hit 35 years old. It's at that moment that I had my first pulmonary embolism. A blood clot appeared while I watching TV...like that Unbeknowst...no stress/I was laughing and talking..and then boom- pain; pain that you never wish to feel deep in your ribcage/close to heart/sternum. My pulmonary artery was jamming due to blood clot that formed after some of 'plaques' had ruptured at that specific moment and then it traveled in the major artery...I nearly died. When it blocks it, oxygenation is stopped in that tissue; the endothelial tissue plastering the artery becomes necrosed because of O2 dropping precipitoulsy in that jammed area. There was not enough oxygen/ATP in my artery, so tissue was dying. And, indeed, that,s what happened inthe following days/immediate weeks after, more and more of these bouts; and sometimes I would have chestsqueezing (just like people experiencing cardiac arrest/heart failure), as if a 1 ton elephant steps on your ribcage and this kills you from Inside. Was it painful...there is no word to describe how painful it was, I wish it now on anyone. It is like torture (pain), like someone stabbing a needle/swissknife repeatedly, same thing, but worse, much worse. You do not feel pain before these events happen, it is why I stress that people REALLY heed there cholesterol levels; it is not a joke because it happens (atherosclerosis/blood clot), you are frail and your chances of surviving are minuscule.

I did. I know am extremely lucky, count my blessings (I think not in years/hours..but in breaths) and very greatful to life. It's alose because I did not want to die/fought as a Survivor. Pain would kill me, unless I fought it/died trying. NOTHING, will save you, if you don'T fight it (not even many medical help right now/statins..etc), its an internal thing. We hope the future the therapy solves this, but for now, you still have to make a Huge change in your life and after having it, your life expentancy drops/frailty/ischemia events/never enough O2 like before in your vasculature (which means ischemic injuries/akin to cyanide levels rising in blood causing hypoxia and necrosis), it can also mean stroke/again due to ischemia/poor oxygenaition to your tissue/organs. You MUST stabilize the plaques as quick as possible. And the Actual Reversion/or slowing of the atherolscerotic lesion process is Slow, dogslow; it takes years; took me 5 years, 5 years later, I'm still hurting from this major life (near)death?) event. Now I know my life will be cut and most likely won't reach my late grand-ma'S age of 92 years old (she never had atherosclerosis and my mom died at 56 of cancer...grim odds, still I'm putting my hopes on grandma and dad still alive, and my twin too; it's going to be this 'who is the twin that outlives the other twin' (or do they live the same length); having hat that I'll probably die before her). The stuff I had is like a disease you get in your 80s...I got it at half-age...*s*xks* indeed but life is no fair. MerryXmas&aHappyNewY anyhow.

Posted by: CANanonymity at December 23rd, 2019 8:59 PM

I have red repeatedly (& without contradiction) that the higher the overall (simple) cholesterol level, the higher the age at death of the body (all cause mortality). What about NNT & lack of life prolonging by statins? We need cholesterol (& Co-Q10) to live long & prosper.

Posted by: Ray at December 31st, 2019 1:44 PM

From what I've been reading lately, higher blood cholesterol levels including LDL-C are protective and do indeed reduce mortality and provide longevity. More forward thinkers these days say blaming LDL for the atherosclerotic plaques is like blaming the "fireman called in to fight the fire". Plenty of more recent research would blame our standard American diet's effect on fasting insulin levels to be the real culprit in the many inflammatory processes. All of this aside, I do find "Reason's" question about pain to be fascinating.

Posted by: Tom at January 10th, 2020 6:06 AM

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