The Telomere Theory of Aging

telomeres ageThis theory is as widespread as it is false, but we suppose it has certain philosophical implications (also false) that keep it going.

The telomere theory of aging is nonsense. The idea is that a cell can divide only so many times. This would mean that life span is programmed in advance. This idea is false as well, but appeals, oddly, to some people. If the telomere theory were true, it would also mean that a sedentary lifestyle would be optimal which, of course, isn’t true either. This would, however, appeal to a large number of people.

Here’s how the theory works: When we evolved from bacteria, with their circular DNA, into eukaryotes (protozoa and multi-celled creatures), our DNA split into pairs of chromosomes, basically strings of DNA. This brought up a new complication: we needed a way to mark and protect the ends. This is where telomeres come into the picture.

The Job of Telomeres.

A telomere is a specific sequence of DNA and is repeated, typically 100 times, rather like wrapping a thread around the end of a rope to keep it from fraying.

This part is true.

Now then, when a cell divides it loses a telomere. 99, 98, 97, …. 1, 0, done. So in this theory, lifespan is programmed.

This part is true too.

The Fly in the Telomere Ointment

However, if you look one level deeper, the programmed cell life falls apart. It has to. Consider the intestine. The intestine replaces itself every four days. By the telomere theory, we would run out of replicable cells in about 400 days. Obviously this doesn’t happen, and it turns out that there is cellular gadgetry that will fashion new telomeres and tack them on. This process occurs where it is needed. We are almost never going to run out of telomeres for the cells that need them. That’s pretty much the end of the Telomere Theory of Aging.

Another counter to the telomere theory is this: an active, energetic person, that eats sensibly, takes exercise, and has stress under control, will replace his or her cells at a much higher rate than a sedentary person who eats poorly or is stressed out. Yet, as we all well know, that healthy person will live longer and be healthier, and this is because his cells are being frequently replaced. He achieves this health not because of the rate of turnover, but because the models for the replacement cells, the stem cells, the master cells in effect, are kept in pristine shape by his lifestyle.

Telomeres Do Have a Major Benefit

Telomeres do throw a nice monkey wrench into cancer promotion. As a cancer cell replicates, it also loses a telomere. It would run out unless it could also replace the telomeres, so this is another barrier. Not an insurmountable one obviously, but cancer cells are defective, so some can’t pull off the new-telomere-construction bit. The more ways cancer cells can run aground, the better off we are.

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