X-Message-Number: 14400
Date: Sat, 2 Sep 2000 07:09:54 -0400
From: Thomas Donaldson <>
Subject: lifespan experiments with drugs

Hi everyone!

While the drug isn't given explicitly, there's not much I can say to
the note in Cryonet #14394.

However ALL readers should know that the discovery of drugs which 
prolong life by various amounts is hardly new. The main problem with
these drugs, which SOME have found important, is that in some cases
the prolonged lifespan seemed not to deal with anything essential to
aging. However I will point out first that the statistics involved in
working out the resulting lifespan with the relatively few animals
that attain relatively high ages does not work out as easily as 
with showing that average lifespan overall does not increase (or
put more bluntly, with some of these drugs the fact that no animal
lived longer than the normal max lifespan does not prove that the
drug did not influence aging: we need many more animals to prove that).
Second, a number of different drugs do have experiments showing 
increases in maximum lifespan.

And here is a list: 2-ME, procaine, deprenyl, levodopa, melatonin, dilantin
CoQ10, HGH, EGb 761. In some cases the experiments used relatively
few animals and (correctly) did not try to work out maximum lifespans.
These include pantothenic acid (B5), pyridoxine (B6), and several
antioxidants. To repeat: with only a small number of animals and a
relatively small effect on lifespan, the maximum lifespans have much
less statistical significance than average lifespans.

Since the worms used in the above experiment live relatively short
lifespans, it may easily be the case that treatments which prolong
their lifespans may not work so well on human beings. We have a higher
level of natural antioxidants than shorter-lived animals, and that
may mean that other factors than simply oxidation may play a bigger
role in us than in them.

			Best wishes and long long life to all,

				Thomas Donaldson

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