On Tue, 8 Jan 2002, Paul Sand wrote:

> That's another point. Increased metabolism may mean shorter lifespan if we
> assume mechanistic wear-out theory but from the other hand more protein and
> increased metabolism means better recovery and rebuilding of a body so it
> can extend lifespan.
> The Inuits which ate up to 10 pounds of meat and fat a day was still able to
> reach 60-70 years in extreme weather conditions.

I think the caloric restriction approach assumes something like
the wear-out theory, or rather the theory that many (all?) of our
cells have a built-in generational limit.  On the other hand, we
just considered a rat study indicating that rats fed 50% protein
did not have oxidative stress, whereas rats fed "adequate"
protein did.  If the free radical theory of aging is correct,
the higher protein intake should offer better protection against
free radicals.

Concerning the Inuit, I remember Stefansson arguing that their
carefully maintained environments (igloo, tightly stitched fur
clothing, etc.) kept the comfortably protected against the
extremes of weather.  If he was correct then we would have to ask
why the life expectancy of the Inuit was shorter than that of
people on SAD.  It is difficult to isolate variables.  In
industrialized societies, the weather may generally be milder,
but exposure to pollutants, accidents, and stress is greater.

Todd Moody
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