Dean Esmay writes.

>There is even some reason to suspect that a lot of
>the side-effects of fasting are actually caused by the ketosis that fasting
>brings on rather than the cleansing involved, though I suspect it's a
>multitude of factors.  (Still, fasting people lose appetite after a while,
>usually, and so do people on low-carbohydrate diets.  They also feel quite
>energetic, another common side-effect of ketosis for low-carbers.)

This is very interesting to me as someone who in the past used to fast
quite a bit for quite lengthy periods. However, no matter how many times or
how long I had fasted, I always had a rough go of it, and got to the point
where I got tired of putting myself through it for the benefits, which were
less pronounced the more times I had fasted. And the more I did it, the
less inclined I was to buy buy the stock argument in the alternative diet
camp that the side effects were all just due to one's body "flushing out
the toxins." (Since if that were true I should have been one of the most
cleaned-out persons ever, and should have experienced less and less side
effects, yet I never did feel great, of had more energy, or felt
better-and-better while fasting as some claimed.)

I would be most interested if anybody has any scientific references that
explain the mechanisms of fasting, levels of ketosis, etc., especially if
they address some of the more common hypotheses by the natural hygienist
camp, which is the group with the most practical experience fasting people
at their retreats for it, and has done the most theorizing (although
documented scientifically, I might add, even though they did generally
obtain good practical results):

Does fasting really:

- "flush out the toxins"?

- Does it really aid "regeneration" of tissues? (The theory being since the
body is supposedly saving so much energy by not having to digest anything,
net anabolic activity vs. catabolysis is greatly increased. This is the
stock "natural hygiene" explanation along with the "flushes out the toxins"
theory for why fasting can help people.) I can attest to the fact fasting
is helpful, but I am not so sure *why* anymore, and I don't necessarily buy
the natural hygiene "experts'" explanations any more.

- Is there anything particularly special about fasting metabolism itself,
or is it just a more extreme form of things like what Dean mentions with
ketosis? Recent experimenters have been looking at the benefits of "caloric
restriction" on animals including primates, which has been shown to lower
aging parameters, and extend lifespan. Is periodic fasting any "better," or
is the fasting state any more productive, since it is a more accelerated or
extreme form of restriction, or could it be worse or less effective for
other reasons?

- I have heard one individual suggest that detoxification actually might be
hindered during fasting (the individual could not provide a reference,
though they said they may have seen this in a journal report somewhere)
since detox is not some catch-all generic "flushing out the toxins" but
rather requires specific enzymes for specific detox biochem pathways. Thus
if body processes are in conservation mode, there might actually be *less*
of the specific enzymes necessary for certain detoxification routes.

- It would also be interesting to know if anyone has explained why some
individuals have near-normal energy levels and feel great during lengthy
fasts, while others (like myself, when I have done it), am reduced to lying
around all day and even then have little if any energy and feel pretty
rotten. It seems to me it's got to be more than just the lower-octane
energy of ketosis compared to glycogen metabolism.

- Chet Day published a number of research excerpts and cites from Medline
in his Health & Beyond newsletter a few years ago. However, many if of most
(if not ALL) of the fasting studies done the researchers included at least
some caloric intake (i.e., none were water-only fasts). The contention in
the N.H. camp has been that during fasting, the body is much more sensitive
to anything ingested, and thus intake of anything but water skews the
clinical results and metabolic measurements the experimenters do. (I can
confirm the extreme sensitivity on water fasts, but am skeptical as to how
much difference there is between a water fast and dilute-juice fasting,
since I have done both.)

- Finally, what would the evolutionary arguments for fasting be, beyond the
obvious observation it would have been selected for to increase survival
rates during famine? Is there any evolutionary explanation or mechanism
that would account for the "rejuvenative" effect of fasting seen in many
individuals that could explained by evolutionary processes?

--Ward Nicholson <[log in to unmask]>