Welcome Josy, I keep an archive of all the posts to this newsgroup at
http://www.pinch.com/skin where you can find answers to many of your
questions about diet by using the search engine.

Whenever most people think of Tryptophan, they think of a turkey dinner.
Oddly enough, this is because of the disease we share, psoriasis.

I too, was intrigued by a psoriasis diet recommendation at an Australian
medical site that made a case for tryptophan being the cause of P.  The
page is still there at http://www.gac.com.au/skipsoriasis.html if you want
to see it.  Please mailto:enquir...@gac.com.au a copy of this post so they
can stop spreading their misinformation.

I posted the whole diet to the group and we had lots of fun speculating
about what had tryptophan and what didn't. Lola was thinking of dieting
anyway so she started the no-trypto diet and proceeded to get loopy from
her percieved serotonin crash. I did some research and shared it with Lola
but I never followed up on my promise to debunk tryptophan for the group.

Tryptophan is an essential amino acid that we get when we eat protein.
The ratio of tryptophan to protein doesn't vary much. Foods that have no
protein have no tryptophan. There is one notable exception; gelatin is
nearly pure protein but cantains no tryptophan. I found this while poring
through a book of nutritional values. Many foods have not had their
trpytophan specifically measured and this is noted with a dash '-' rather
than a zero.

Well, back in 1967, two young doctors at Mt. Sinai Medical center in New
York noticed that one of their hospitalized patients, a woman with
psoriasis, had an impressive remission during her stay. She was being
treated for another illness but the only thing the doctors could think of
that might be responsible for the improvement was her bland diet of
hospital turkey. They looked up turkey in their nutritional reference and
found nothing for tryptophan. Intrigued, they sent out a sample of the
turkey for protein analysis and got a report that no tryptophan was found.
(Sound familiar? Think Skin-Cap.)

On the basis of this, they published their findings in the medical journal
Lancet, along with astounding before and after photos (in black & white).
No matter that the lighting of the woman's butt was horrible in the before
picture and almost flattering in the after shot. When the media got hold
of the story, it made its way to national news.

Unfortunately, the whole premise was wrong. Clinicianss reported to Lancet
that trials of turkey and restricted tryptophan diet had no bebefit for
their psoriasis patients. Nutritionists reported that the levels of
tryptophan in turkey are on par with any other bird, and poultry has a
relatively high amount of tryptophan (by just a few percent).

Well, the retractions made it to the media and apparently this came about
right around the holidays when everyone is feasting on turkey. What they
reported to the world was that turkey really does have tryptophan in it,
and lots of it. That got embellished with the tidbit that tryptophan is a
precursor of serotonin in the brain, and serotonin makes you feel
satisfied and sleepy.

I can almost imagine Walter Cronkite tacking on a human interest story
about how turkey makes you sleepy. What a great excuse to waddle away from
the table for a nap without helping with the dishes.

Well, it turns out that the tryptophan-sleepiness myth is bogus too
because tryptophan competes with all the other amino acids in protein to
get across the blood/brain barrier. Only when the body has assimilated the
the other amino acids can tryptophan get into the brain. This happens when
the muscles burn carbohydrates. Nutritionists say that for a warm glass of
milk (protein) before bed to have any effect, the trick is to add some
honey.

So, the whole turkey-tryptophan-sleepiness urban legend is because of one
happy woman who had a remission of psoriasis.

There's a moral to the story:  If only those doctors hadn't jumped the
gun, they might have found the real reason for her remission.

Even more absurd than the turkey story is that tryptophan has been banned
by the FDA since one tainted batch from Japan caused several deaths around
the turn of the decade. Because tryptophan is a normal constituent of
protein yet is not allowed by the FDA, protein food supplements must be
processed to remove it. Untainted tryptophan is perfectly safe and has
many uses such as a natural diet aid and anti-stress supplement.

Ed "I wish I had some tryptophan" Anderson