Michael Eriksson's Blog

A Swede in Germany

The reserve theory of survival

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As an addendum to some of my texts on COVID (e.g. [1] from earlier today):

In my thinking around survival and longevity, I tend to rely on the “reserve theory [of survival]” or “reserve principle [of survival]”. (For want of a better name. While the idea is reasonably obvious, and likely to have been had by a great many others, I cannot recall ever having encountered it outside my own thinking, and I am not aware of any names other than my own.)

The idea is that we all have a certain reserve in various bodily functions/organs/whatnot that is more than enough to handle a relaxed and unstressed situation, even for most elderly. However, if these reserves are exhausted, either because of an increase in stress or a decrease in the reserves, then we have a problem—possibly, a deadly one. For instance, that very old lady might have enough reserves to e.g. go to the store, but if her handbag is snatched, trying to run down the thief might be too much. Similarly, a bout of flu might reduce her reserves to the point of making even a store visit a life-threatening experience. (Leaving aside whether someone with the flu, irrespective of age, should be running around town.)

These bodily whatnots include factors like heart, lungs, kidneys, liver, … Even someone with e.g. a bad case of liver disease can live in the now, at least with some care, and maybe even reach a respectable age, but his life expectancy is likely to be well short of what it could have been, because further losses of liver function are covered by lesser reserves than they would have been with a healthy liver.

The problem with age is, of course, that various damages, wear and tear, age related deficits, whatnot accumulate over the years, while the state of training tends to worsen. (With the lesson that those things that we can still train with age might be well worth training. It is no coincidence that the active elderly tend to live longer than the inactive.)

A good example is the heart, in a simplified model, where two values, resting heart rate and maximal heart rate, can illustrate the reserve. A sporty teen might have a resting heart rate of 50* beats per minute and a maximal heart rate above 200—a reserve of more than a 150 beats per minute or 300% compared to just resting. Wait until the same person has grown 90 and out of shape, and the same numbers might be 100 and 120—a reserve of 20 beats per minute and 20%. Which incarnation will have a problem with that flu?

*Numbers should be taken with a grain of salt. They are intended for illustration, not medical exactness. (But I do not consider them unreasonable.)

A problem with both the vaccine debate, in as far as risks are at all acknowledged, and medicine in general is that there is little concern for such reserves—the patient survived now and what comes later is not our problem. If that lung cancer patient had one lung removed to successfully remove the cancer, he was “healed”—but what about his life expectancy with that lung gone? How many years of his life might that have cost him? (But note that I am not saying that the decision to operate was faulty. It might very well have been the lesser evil and an objectively correct decision. The point is that there is a difference between truly being healed and being “healed”.)

Now, looking at COVID vaccines: Let us say that someone experience some side-effect, e.g. a heart issue, for some time, and then bounces back. There was no death—so no big deal. Right? But what if the side-effect left a permanent reduction in reserves? A little bit of scarring on the heart muscle, e.g., might not be very dangerous at twenty—but what about the same heart sixty years later? It might, for instance, be the difference between a deadly and an almost deadly heart-attack, because the reserves needed to survive were not there.

(Of course, similar thinking might be needed with COVID, it self, or any other disease.)

An outright disgusting related area is the description of some developmental problems affecting the brain with e.g. “most have a normal intelligence”. The hitch? The word “normal” is taken to imply an IQ above 70, or two standard deviations below the mean. These cases of “normal” intelligence might then have taken a hit of two standard deviations compared to where they “should” have been—a truly massive loss. In individual cases, we might have someone who “should” have been a genius, suffered some mishap, and ended up with an IQ half of what he might have had—-but, because he is still above 70, he is deemed of “normal” intelligence.

Written by michaeleriksson

January 20, 2022 at 5:19 pm

Posted in Uncategorized

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