Death, Aging, Rejuvenation (Part 1)

One bias for caloric restriction experiment in my opinion is following. Rats live in cage 30cmX60cm for their whole life. There are at least five rats or 20 mice. They live couple years and die. During the experiments they are celebrities when they live 5 years - some lucky ones. The Food is a balanced mixture of nutrition. Caloric restriction is - 60% of their regular meal. They practically don't move - there is no space in cage. Mostly they sleep whole day. Sometime they fight and mate. They live in those conditions at Yale, at Med U of South Carolina, at Russian State Medical University and I think everywhere else. To compare our fellow humans we would place 10 people on area of 20 square metres (200 sq. feet) for 50 years in a row, feeding them with what they want but all the same - let say junk food from McDonalds.

I remember my cat (who was partially wild) stole meat and ate until it started to vomit. He repeated it many times when he was able to steal some steak or whatever. The same happens in wild - lions have maybe one successful hunt out of ten. When they catch a prey, they eat like crazy. Much more than they can digest at the moment. So it looks like there is an instinct. Eat as much as possible. This is not a joke - 60% of people in western countries are overweight. Abundant high calorie food and lack of activity. It does not seem that for these people any internal mechanism restricts food consumption. Applying this back to rats, we can see that what is considered normal consumption - "ad lib" - maybe actually big overfeeding of the animals in these cages. In this case 60% of caloric restriction would be just what rats need, just what the calories they spend in lazy, uneventful daily life. So called "control", "normal" rats - that fed as they usually fed might be compared for fat overweight humans. They consume junk food. They prone to the bunch of diseases of obesity and low activity. Heart diseases, strokes, variety of cancers, arthritis, etc. In this case all the hype about caloric restriction would just be brought to the business of mere balancing diet and activity in so called "calorie-restricted animals". I haven't seen any discussion of this problem. I might be wrong. This is why I use caloric restriction for myself. I did not work with worms and spiders. But my guess would be that they all are also in artificial standardized conditions. "Control" worms might be also overfed. To put rats into bigger cages (to increase activity in control group and balance calories and catabolism) would be incredibly expensive. Even at present conditions because of "animal lovers" and bunch of other regulations and considerations (e.g. sterile conditions), the price of animal housing is sky-high.

You would say animals in wild would live longer because they balance activity and consumption. Well, recently I read that life span of animals in wild is shorter than animals in captivity. Correct me if I am wrong: pandas live 15-20 years in nature and 20-30 in zoos, bears 20-25 in nature and 30-40 in captivity. Civilization has certain benefits - vaccinations, good medical care, more or less good hygiene. So just moving into wild conditions wouldn't make you younger or allow to live longer.

Now, to discuss rejuvenation procedures, I would need to talk about aging first. In this case Rejuvenation could be considered as reversal of aging (deterioration). Longevity is different story - it is prolonged life span. Rejuvenation supposedly should lead to longevity. But longevity is not equal to Rejuvenation. Aging leads to Death eventually. It is easier to discuss from that end.

All written here is just plain speculation, take it with a grain of salt.

- continued in Part 2

About the Author

Aleksandr Kavokin, MD,PhD http://www.geocities.com/aging_rejuvenation/ http://www.geocities.com/usmle_test aging_rejuvenation@yahoo.com