Index Home About Blog
From: ((Steven B. Harris))
Subject: Re: Potential toxicity of H2O??
Date: 31 May 1995

In <> (Steven Wm. Fowkes) writes:

>In article <3q2t4i$>,
>Steve Harris writes:
>>>Response from Angelo Schouten:
>>>One story from the "field": The english elite fighting forces SAS are
>>>trained to survive in the wild. They drink water *only* after they
>>>boiled it with leaves of trees. The reason is that is better absorbed
>>>that way.
>>  Baloney.   It isn't.  Just because the English have a fetish about
>>drinking water which has had leaves boiled in it (and they do) doesn't
>>mean there is any SCIENCE behind it.  It's just... English.
>I was told by a "field" scientist that had been treating starvation
>and dehydration in an African famine that "regular" water (probably
>just filtered) killed a significant percentage of seriously
>dehydrated starvation victims. But they discovered if they added tiny
>amounts of fruit juice to the water, they were able to rehydrate
>almost 100% of their patients. Is there a comonality between fruit
>juice and boiled leaves? I can certainly see a possibility here.
>Steven Wm. Fowkes (       voice: 415-321-CERI
>Cognitive Enhancement Research Institute        fax: 415-323-3864
>PO Box 4029, Menlo Park, CA 94026 USA           alt: 415-321-6670

Well, there's a big problem with "rehydrating" starvation victims, since
you're almost always feeding them also.  When they get cellular energy
charge back they pump phosphate and K back into their cells and die of
acute hypokalemia (low serum potassium) and hypophosphatemia.  The fruit
juice can help with the first, and doctors learned long ago in acute
treatment of starvation that a little milk helps with the last (so in
that last epiphanal scene in Grapes of Wrath, the starving man is
getting the Right Stuff).  But neither of these problems has anything to
do with rate of free water absorption in healthy people.

                                              Steve Harris, M.D.

From: ((Steven B. Harris))
Subject: Re: Potential toxicity of H2O??
Date: 07 Jun 1995

In <3r1nia$> Nowhere@anywhere.soon (Angelo
Schouten) writes:

>>        Since the word "osmosis" is getting thrown around a lot
>>in this discussion, let us actually ask what the theory of osmosis would
>>say about this. If we consider the gut as a membrane separating a salty
>>compartment (blood) from ingested liquids, then hypotonic liquids (like
>>pure water) would cross into the bloodstream fastest, isotonic liquids
>>(water of a physiological salt concentration) would not move at all, and
>>hypertonic liquids would actually *remove* water from the bloodstream.
>>In fact, I know from my first aid training that this is exactly what
>>happens in the lungs of drowning victims (fresh water drowning victims
>>often have screwed up electrolytes from all the water rapidly crossing
>>into their bloodstream, whereas in sea water victims the hypertonic
>>water does not leave the lungs). Perhaps unlike the lungs the gut is far
>>from an ideal membrane, so the theory of osmosis does not apply.
>>But if so, all this talk about "osmotic shock" from pure water should be
>>dropped. You can't say pure water causes osmotic shock AND is poorly
>>absorbed into a salty compartment at the same time!
>>---Brian Wowk

Comment: exactly.  The gut has many more tight junctions between villi
cells than the lungs have between alveolar cells, and these prevent
absorbtion of even pure water in the gut fast enough to cause shock.
Water in the gut goes through 7 to 15 angstrom pores in these tight
junctions, and does so entirely by diffusion.  It does directly from gut
lumen into blood without passing through gut cells (read previous
sentence again).  The less concentrated the chyme, the faster the
diffusion-- up to the limit imposed by pore number.  Again there is
absolutely NO physiological reason to think that water with salts is
transported faster.  Indeed, in the lower gut where osmotic
concentrations increase after digestion, diffusion of water out is
LIMITED by ability to actively transport solutes, since again the water
diffuses out passively through the pores, along the osmotic gradient.

If you drink seawater fast enough BTW, you CAN go into hyperosmolar
shock, but it takes more seawater and again is not as easy as in
seawater drowning.  Again the reason is  passive (but again slower)
diffusion of water from blood into gut without traversing cells.

>Sorry Brian I do not see why this is conflicting in any way with the
>story on secondary drownings, or with your conclusion for that matter.
>You merely described osmosis and that is all. Osmotic effects are to be
>seen with a line of cells (or isolated ones). Fact of the matter is that
>more "work" needs to be done to reach the former cellular equilibrium in
>*any deviation* from the normal physiological concentration. The
>directional flux of water depends on hypo or hypertonia and any
>concentration gradient is an additional barrier to be conquered.

Irrelevent.  Imbibed water does not traverse cells, and so there are no
concentration gradients to be conquered for it.  You absorb water much
like you do oxygen.

>I do not understand why *I* am -in fact- defending the SAS practical
>implications of boiling water with leaves.

That makes two of us.

> As soon as I find out I will ask
>Steve Harrish to become the all-American sportdrinks marketeer, with me
>negotiating with the English and you taking care of the cooling. We can earn
>lots of Money. Follow the next episode of The Three Amigos!!!

A fantasy by

>Angelo Schouten

Index Home About Blog