Stress? What Stress?

Stress? What Stress?

July 28, 2008, 10:03 am
Filed under: Alzheimer's, Genetic Testing, Health, io9, NPR, Predictions, Science, Science Fiction, Sleep, Writing stuff

Some years back a good friend sent me a postcard from Florida with the image of a tri-colored heron’s head (you can see the image from which the card came here). On the card, the heron is looking straight at you, top feathers standing straight up, and above it in bright blue ‘electric’ lettering are the words “Stress? What Stress?”

It’s been tacked to the wall next to my desk here since. And it has been something of a standing joke between my wife and I. When things have gotten bad from time to time, one of us will turn to the other and simply say in a squeaky, high pitched voice “Stress? What Stress?”

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A month ago I wrote about slowly coming down from the prolonged adrenalin high which was being a full time care provider. Doctors have known for a while that such long term stress was hard on care providers. It’ll drive up blood pressure, screw with your sleep habits, and even compromise your immune system. Now they have started to figure out how that immune system mechanism works. Last night I caught a piece on NPR’s All Things Considered with UCLA professor Rita Effros about her research on this mechanism. What professor Effros said (no transcript yet, so this excerpt is my transcription):

So, in the short term cortisol does a lot of really good things. The problem is, if cortisol stays high in your bloodstream for long periods of time, all those things that got shut down short term stay shut down. For example, your immune system.

…

But let’s say you were taking care of an Alzheimer’s spouse, or a chronically ill child – those kinds of situations are known now to cause chronic, really long-term stress – let’s say years of stress.

…

(These care providers) were found to have a funny thing happening in their white blood cells. A certain part of the cell is called the telomere, which is a kind of a clock which keeps track of how hard the cell has been working. Their telomeres got shorter and shorter, and it has been known for many years that when cells have very short telomeres they don’t function the way they’re supposed to function.

What happens is this: cortisol inhibits the production of telomerase – a protein which helps to lengthen and buffer aging effects. Abstract on the mechanism is here, and it says it succinctly:

BACKGROUND:
Every cell contains a tiny clock called a telomere, which shortens each time the cell divides. Short telomeres are linked to a range of human diseases, including HIV, osteoporosis, heart disease and aging. Previous studies show that an enzyme within the cell, called telomerase, keeps immune cells young by preserving their telomere length and ability to continue dividing.

FINDINGS:
UCLA scientists found that the stress hormone cortisol suppresses immune cells’ ability to activate their telomerase. This may explain why the cells of persons under chronic stress have shorter telomeres.

IMPACT:
The study reveals how stress makes people more susceptible to illness. The findings also suggest a potential drug target for preventing damage to the immune systems of persons who are under long-term stress, such as caregivers to chronically ill family members, as well as astronauts, soldiers, air traffic controllers and people who drive long daily commutes.

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io9 picked up on this story, and gave it a nice Science Fiction spin:

Stress runs down the body’s immune system, which is why people with high-stress jobs or events in their lives are vulnerable to illness. Now a researcher at UCLA has discovered the link between emotional stress and physical damage — and she’s going to develop a pill that will allow you to endure stress without the nasty side-effects. And there may also be one good side-effect: Extreme longevity.

It turns out that when you’re under stress, your body releases more of the hormone cortisol, which stimulates that hyper-alert “fight or flight” reflex. While cortisol is good in small doses, over time it erodes the small caps at the end of your chromosomes known as telomeres (the little yellow dots at the end of those blue chromosomes in the picture). Many researchers have long suspected that telomeres would provide a key to longevity because they are quite large in young people and gradually shrink over time as cells divide.

Rita Effros, the researcher who led the UCLA study, believes that she can synthesize a pill that combats stress by putting more telomerase — the substance that builds telomeres — into the body. This would keep those telomeres large, even in the face of large amounts of cortisol. It might also make your body live a lot longer too.

[Spoiler alert!]

Curiously, this clue about telomere length and aging is exactly the mechanism I use in Communion of Dreams to reveal that the character Chu Ling is a clone. Genetic testing reveals that the telomeres in her cells are much shorter than would be expected from a child her age, leading to the understanding that this is due to the fact that she has been cloned.

Ironic, eh? No, no one is going to think that I’m a clone. But I find it curious that the same mechanism which I chose for a major plot point pertaining to the health of the human race in my book is one which has been clearly operating on my own health.

Fascinating.

Jim Downey

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