> -----Original Message-----
> From: Paleolithic Eating Support List
> [mailto:[log in to unmask]] On Behalf Of Andrea Hughett
> Sent: Thursday, December 07, 2006 2:08 PM
> To: [log in to unmask]
> Subject: Re: Cooking Fats - was Re: Christmas Pudding
> 
> ...
> I have never quite understood why yeast is non-Paleo.
> After all, there are wild yeasts in the air, and
> certain foods that hang around for a while will
> provide a hospitable environment. Same way with
> vinegar - it may not have been a major item in the
> diet, but fruits and vegetables kept for a while would
> have the potential to ferment and then turn to
> vinegar.
> 
> Andrea
> 

There are people who say that ingesting yeast contributes to internal yeast
overgrowth or infections ("candidiasis"). Some examples:

- "Most nutritionists agree that any good candida diet should reduce as much
as possible processed sugar, yeast, dairy, wheat, caffeine, nicotine and
alcohol. They are the main culprits because they help candida yeast to
grow." ("Candida Diet," http://www.pureliquidgold.com/candida-diet.htm)

- "Avoid anything containing yeast: brewer's yeast, baker's yeast, vitamins
derived from yeast." ("Curing Systemic Candida without GP help - questions,"
http://forum.lowcarber.org/archive/index.php/t-46221)

On the other hand, there don't seem to have been a lot of studies done on
the harmful effects of yeast and some people claim that vinegar has
medicinal properties. Also, studies have shown health benefits from
yeast-containing wine and Cordain allows wine in his diet plans for anyone
who doesn't have a serious auto-immune disorder. For the latter, he believes
that even dead yeast proteins might trigger a hypersensitive immune system.

Fermented fruit might have been eaten occasionally by Paleolithic peoples,
but not enough to make the yeast it contained a staple ingredient. It was
not until the first alcoholic beverages around 10,000 years ago (beer or
perhaps mead) that yeast would have become a significant ingredient in human
diets, and even then only in certain regions (alcohol was still rare among
indigenous Americans when Europeans arrived in the Americas). 

Cordain and Audette don't talk about yeast much in their books and don't
include it in their summary lists of foods to avoid (though they do briefly
say it should be avoided within the text of the books). That is a bit
curious. Below is some info on vinegar from Cordain that was posted in this
forum. Cordain boils it down to this: "vinegar could not have been consumed
by pre-agricultural people, and yeast containing foods were rarely if ever
encountered."

Date:         Sat, 1 Sep 2001 14:59:14 -0400
Reply-To:     Paleolithic Eating Support List
<[log in to unmask]>
Sender:       Paleolithic Eating Support List
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From:         matesz <[log in to unmask]>
Subject:      vinegars!

Cordain's reply to the vinegar questions:

Hi Rachel,

You are correct in questioning whether vinegar influences intestinal
permeability.  It is well established that disease, alcohol, non-steroidal
anti-inflammatory drugs, capsaicin derived from peppers (paprika, cayenne
etc) and dietary lectins (at high concentrations) may increase intestinal
permeability.   Some of this evidenc[e] comes from human interventions --
some from animal studies.

With vinegar, there is only animal data, and whether or not these data can
be translated to humans is still speculative.  Colitis (inflammation of the
colon) is routinely induced in rats by injecting acetic acid (vinegar) into
the rectum (Al-Awadi FM, Khan I. Blood purine and energy status in rats with
colitis. Dig Dis Sci 2001 Feb;46(2):443-8).   However, the concentrations of
acetic acid are a bit higher than the 5 % typically found in vinegar.  Also,
it is not known if ingested vinegar remains intact through its passage from
the stomach to the colon in humans at typical dietary concentrations.

We believe that most of the interaction with the gut and the immune system
occurs not in the colon, but rather in the small intestine. Suplhydryl
compunds normally found in cells of the intestinal mucosa are essential for
maintaining intestinal integrity and preventing increases in permeability.
Substances such as iodoacetic acid (a close analogue of acetic acid) blocks
sulphydryl compounds at a 2% concentration and causes inflammation of the
small intestine and increases in intestinal permeability characteristic of
Crohn's disease in animal models (Rachmilewitz D, Okon E, Karmeli F.
Sulphydryl blocker induced small intestinal inflammation in rats: a new
model mimicking Crohn's disease. Gut 1997 Sep;41(3):358-65.).  Whether or
not this series of events occurs in humans with vinegar in humans is not
known.

Most vinegar also contains yeast or residual proteins from yeast. Yeast
proteins contain multiple peptides that potentially may interact with the
immune system via 2 and/or 3 way molecular mimicry by virtue of
cross-reactive peptide sequences.  Whether or not yeast, or for that matter,
any other dietary food substance elicits or aggravates autoimmune diseases
in humans is still unknown.  The only exception to this is gluten (wheat,
rye, barley & maybe oats) and celiac disease and gluten and dermatitis
herpetiformis (a skin disease).

However, that being said, there is virtually no risk in removing vinegar
from the diet, and potentially many benefits, particularly for people who
may have autoimmune disease or gut related illnesses.  Clearly, the
evolutionary model of nutrition indicates that vinegar could not have been
consumed by pre-agricultural people, and yeast containing foods were rarely
if ever encountered.  I believe that we should follow the lead given us by
eon's of evolutionary wisdom.

You certainly can post this to the Paleo Food group to clear up this issue.

Cordially,

Loren