[extropy-chat] Re: Aging as a function of bone marrow degradation

[Brett Paatsch]

Harvey Newstrom wrote:

> Lifespan Pharma Inc/ MFJ-CTO writes:
>> Actually I have been thinking about this for many years (over 2  decades) 
>> and what  has to be done is to put the body into
>> near hibernation state and slow metabolism to a crawl.
>
> Is there any evidence that animals that hibernate live longer than animals 
> that don't?  Or that preventing an animal from hibernating shortens its 
> lifespan?  I am not sure that the assumption that hibernation slows down 
> aging is necessarily true.

Offhand I can't recall specific evidence. Animals that hibernate tend to be
specimens of species that hibernate and cross species comparisons are
not completely trivial as other variables get introduced.

Steven Austad to name just one person has almost certainly done some
relevant work here. I suspect that it would almost *have* to be at least
slightly true that hibernation slows aging (vs the exact same animal not
hibernating) from cellular biology first principles.

Animals like bears, burn up stored supplies of fat during hibernation.
Their cells still use energy, in the form of ATP, whether they are
hibernating or not, although not as much as if the animal was running
around, they just get the energy from fat stores and oxygen rather than
food.

One of the biggest things that causes aging at the molecular and cellular
level is oxygen free radicals being produced as a by product of
mitochondria going about the business of producing ATP to be used
to power cells at the biochemical level. Mitochondria did not evolve in
such a way that it had to care that oxygen free radicals would be
produced as a by product so long as the amount of incidental molecular
damage (aging from free radicals) was no so great as to affect the genes
getting into the next generation.  Things that affect the chances of genes
getting into the next generation are selected for or against. Normal aging
hasn't historically (in biological terms) been one of those things as it 
only
became a problem when the reproducing task was out of the way.
Unless grandmothers or grandparents cared enough for their descendants
that their grandchildren could get some concrete edge by having them
around and helpful. Old elephants may remember water sources in
severe droughts etc.

Hibernation seems to be a strategy adopted by some species to match
their food gathering efforts with the times when food gathering is likely
to be cost effective for them.  When there is going to be bugger all
return for effort to be had chasing food in winter it probably makes
sense in terms to eat more beforehand and then live of the fat stored.

Humans live of fat (or glycogen) stores while we sleep and between
meals as well.

Do we age slower while we sleep?

I'd guest that its probably slightly slower but perhaps not all that much.
Our cells (which include more than just our muscle cells) are working
on stuff that cells have to do (which is more than just moving us about)
almost as hard when we are relatively inactive as when we are active
and so ATP is still being generated by mitochondria and free radicals
are still produced as a side effect.

Brett Paatsch