How To Live Forever

How To Live Forever

The lastest issue of The Econmist magazine had a fascinating article. The title of the article is How To Live Forever. It points out that we have not defeated ageing yet. But we are in range of a cure for ageing.

To understand any possible magical cure for ageing, we have to establsih some basic principles. People,like machines, literally wear out. However a machine can always be repaired and its life span extended indefinitely provided we are willing to spend the money. All of us calssic car buffs understand that.

People often feel that a machine is worth repairing. Nature does not take the same view. We humans consider survival an imperative. After all, we cannot reproduce if we are not alive. Those of you who speak German know the phrase "Bleib ubrig." It means in a literal sense "stay alive." In a broader philosophical sense it means that if one is no longer alive nothing matters anyway.

The problem is that the individual's desire not to age is opposed another evolutionary force-the disposable soma. The soma (ancient Greek word for body) is all the body's cells with the exception of sex cells. The soma's mission is to get those sex cells and thus the organism's genes into the next generation.

Nature takes the view that every oranism is going to die eventually. If it is not disease then an accident or a homicide will destroy the organism. Threfore in the eyes nature it is not economically feasible to invest in repairs when those same resources could be used for reproduction. We have makeshift body repairs including healing of wounds and anti bodies to fight diseases.

Aubrey de Gray is a researcher in Cambridge, England. His background is in engineering and not in life sciences. He sees ageing having seven components as follows:

1) Cell loss

2) Aoptosis resistence (the tendency of cells to refuse to die when they are supposed to.)

3) Gene mutations to the cell nucleus

4) Gene mutations in the mitochondria (the cell's power packs)

5) The accumulation of junk inside the cell

6) The accumulaton of junk outside the cells

7) The accumulation of inappropriate chemical links in the material that supports cells

Dr. de Grey believes that managing your wear and tear may not be as complicated asit looks. He links the last five items on his list to one word - oxidation. We all know about ani-oxidant creams and supplements. If Dr. de Grey is right ,they do some good and are taking us in the right direction.

He sees the biggest source of ageing is chemical activity of the mitochondria. These are the places where sugar is broken down and reacted with oxygen to produce energy needed to power a cell. In we humans a massive amount of oxygen is used in this process. A lot of it goes missing. Instread of reacting with carbon from the sugar to form carbon dioxide, it forms highly-reactive molecules called free radicals. These radicals go around oxidizing other molecules such as DNA and protein. This creates all sorts of problems. Dr. de Grey feels that if we can free up radicals and their relatives we can slow ageing. He sees antioxidants as the chemicals to use to get rid of radicals.

This ties right in with the research of the late Dr. Bruce Ames of the University of California Berkeley. He bgan his career studying cancer. He found that damage to certain genes caused cancer. This limited their ability to fight tumours by stopping cell division in the toxic invaders. He gradually changed his focus to the more general damage that oxidation can do and what might be done about it.

He looked at Vitamin C and went past this to two other chemicals as follows:

1) Acetyl carnitine

2) Lipoic acid

When he fed these chemicals to elederly rats, their vigor and memry improved. He conclude dthat these helped a mitochrondrial enzyme called carnitine acetyltransferase to do its job. Boosting their levels seem to compensate for oxidative damage. Dr. Ames further came to the conclusion that high doses of Vitamin B and other vitamins could limit the damage causes by oxidation.

One way that might let people outlive their limits imposed by disposable somas is to accept the machine anology. When you take your car to the repair shop, you expect your mechanic to replace the worn or defective parts. This is roughly what those proposing an idea called partial immortalization have in mind. They propose to make the new part sof the human body with Stem cells. Stem cells are different from other cells in that they have permission from nature to multiply indefinitely.

All of this runs up against 3 billion years of nature on this planet (And God knows howe many billions of years on other worlds.) There are all sorts of genetic locks on cells to stop them from reproducing once they arrive at their physiological destination. One lock is called the Hayflick lock after its discoverer Leonard Hayflick. Some partial immortlizers hope to completely abolish the Hayflick lock all together.

In theory every part of the body except the brain could be replaced in this way. Even in this most complicated part of our body, stem cells are being used to treat Parkinson's disease and other ailments.

Neither prevention or repauir is ready to roll out. But ther is one way that has been proven to extend life--eat less!!

My wife, Elena E. Torello, MD, will comment on the moral and ethical aspects of extending life.

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