X-Message-Number: 10605
Date: Sun, 18 Oct 1998 10:32:50 -0400
From: Thomas Donaldson <>
Subject: CryoNet #10597

To Mr. Brian Delaney:

You are wrong in your statement that only deprenyl has shown an
increase in maximal lifespan. I will say, though, that a lot depends
on just how you define it. Furthermore, calorie restriction, unlike
the various drugs, has been known for more than 60 years and has
been repeated with variations many more times than any extant drug

It's also true that ANTIOXIDANTS have at best shown an increase in
average lifespans. But antioxidants are far from the only ones that
have been tried.

IF we define maximal lifespan as the maximum lifespan of any animal
in the drug versus the control group, then L-Dopa,melatonin,dilantin,
and CoQ10 all show curves with the maximum lifespan reached by 
the treated animals. This work was also done after the possibility
of calorie restriction in treated animals was known and controlled
for. HGH (human growth hormone) also provides an interesting special
case, since the experimenters seem to have run out of their supply
(it was more expensive than now, and remains expensive) before their
test mice died off. By that time, ALL their controls had died off,
while slightly under half the test mice still remained alive.

You may wish to argue against a small number of experiments. Fine.
You may also have some disagreement with the definition above of
"maximal lifespan". The only cure for the first problem is more
experiments. As for defining "maximal lifespan", especially when
the number of experiments on a drug or treatment is small, I find
it difficult to work out any clear definition other than the one
I gave. NO one keeps statistics on the lifespan of every lab mouse
in existence, and such statistics are unlikely to mean very much
anyway. As for the maximal lifespan of any lab mouse involved in
an experiment with drug X, there are problems, too. The conditions
in each experiment are unlikely to be identical, either in the strain
of mouse or in their treatment and the treatment of controls.

I will be blunt, not about what you say but about the current state
of aging research: I think that the emphasis on calorie restriction,
with little attempt to work out exactly why and how it has its 
effects, simply won't get us very far. The issue is that of finding
some regimen which works better because it touches on fundamental
causes of aging better. Yes, the experiments on all the drugs I
listed should be replicated. They might even tell us why calorie
restriction works, if pursued. I do find it odd that an experiment
in which treated animals live longer than untreated ones, and even
have a maximal lifespan longer than that for untreated ones, will
not at least be replicated and studied for what it might tell us
about aging.

			Best and long long life,
				(by whatever means!)

				Thomas Donaldson

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