12/04/2007

12-04-07 - 2

"Calorie Restriction" is still a relatively new area of research, so let's not presume it's right yet, but it's not really a huge surprise that it would prolong life. Basically what you're doing is putting your body into semi-hibernation. If you're on a severely calorie restricted diet (they recommend 1000-1500 calories), and you've acheived a steady state (no longer losing weight), that necessarilly means that your physical activity level is very very low. Basically you're consuming very little and doing very little. All the pathways of your body slow down and do less, your metabolism does less, your mitochondria don't have to work as much, etc. If we assume that each element in your body has some fixed failure rate, like eg. cell division has a 1% chance of screwing up each time - the less you work the longer you can postpone destructive failures. (this fixed failure rate is in fact a good model for DNA/RNA transcription and also for production of free radicals and misformed proteins).

To put it another way so that you can see how retarded this idea is - if you severely reduce the amount of gas you use in your car, your car will last much longer. Yes, of course this is true, because using less gas inherently means you are driving less, and accelerating less, and the life of the car is roughly based on how much you use it, not calendar age.

On the other hand this may be part of the reason why some people who seem super fit don't live longer. Naive people often think it's ironic when a serious runner dies young. They think all that running was for nothing because it didn't prolong life. That's almost as foolish as thinking that running a marathon is good for your health. Moderate exercise probably prolongs life (though there are so many other factors that it's not a 100% correlation). Very heavy exercise, however, probably shortens life. For one thing being in a near-starving state as distance runners often are is very hard on the organs and the brain. For another thing, the opposite of calorie restriction, which is a high "g flux" (consuming a ton of calories and burning a ton of calories), almost certainly shortens life, because you are constantly breaking down and creating new cells and proteins which is putting a big strain on your body and increasing the chance of mistakes happening somewhere in all that molecular work.

I personally choose to live the high g-flux lifestyle myself, just as I choose to use alcohol and drive fast and do many other things that are likely to shorten my life. I totally don't understand the desire to slightly increase your predicted lifespan by giving up quality of life today. Are those extra 0.5 years when you're 85 really going to be awesome? (of course people do retarded things in the opposite direction too, like choose to not wear a seat belt because they don't like the feel of it; okay, you choose to greatly increase your chance of severe injury in an accident because you don't like the feel of the strap, good decision, let me make sure you are never my manager).

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