On Wed, 10 Mar 1999, Mary Jones wrote:
> Some of you may remember that I am a nurse running an interdisciplinary program for PWP's and have enlisted your help before !!
> Today a patient and carer have told our speech pathologist that PWP should not eat bananas. The PWP's son apparently "saw that on the Internet". Does anyone know anything about bananas and Parkinson's ?? We would be interested in comments or knowledge you may have.
> Many thanks again for help.
> Mary
I happen to just now have found the following info. Haven't
looked in PD specific sites. Sorry, don't have all the USENET article
numbers in these. These are just preliminary leads for your
query, and rather long, sorry.
From my reading of this, I'm not sure what effect eating bananas
would have on levels of anything *in the brain* The posters
are discussing serotonin levels in the *blood* where it usually
isn't found in any great amount.
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5-HTP (was: Ignorant Steve B. Harris)
Author: Steven B. Harris <[log in to unmask]>
Date: 1999/02/22
Forum: sci.med
_________________________________________________________________
In <[log in to unmask]> Ed Mathes <[log in to unmask]>
writes:
>
>> as it naturally leads into
<snip, mine
>Steve...out of curiosity on 5-HTP. I was reading n article on obesity
>written by an MD for an NP publication. She recommended 5-HTP in
addition
>to a few other supplements to aid in weight loss.
>
>You, I know, have commented ganst 5_HTP. Why?
Because it gets turned into serotonin in your liver, and dumped into
your blood (depending on your B6 status, in part). Same enzyme does
the job which does it for L-dopa (so it goes to worthless dopamine
before it can get across the blood brain barrier). Your system is not
built to handle much serotonin in the blood. SSRI's don't increase
serotonin levels in blood (only in the brain), but fenfluramine, as
well as methysergide and ergotomine, are all direct serotonergics (as
shown by their direct pulmonary hypertension on toxicity studies).
But serotonin does more than just cause pulmonary hypertension. It
also causes direct proliferation of myocytes, which grow where they are
not supposed to, and cause heart valve deformities. These are not only
seen with fenfluramine, methylsergide, and ergotomine, but also seen in
serotonin syndrome in carcinoid tumors, and in the best and largest
(but by no means all) studies the amount produced correlates with the
valve damage. And this valve syndrome has ALSO been described in West
African populations eating large amounts of serotonin in green bananas
(Matoki). You would think that with this much evidence some people
would be convinced that serotonin causes the valve syndrome in
carcinoid. But no-- since it hasn't been reproduced in animals, there
are still some unbelievers. Duh. The situation reminds very much of
AIDS and H. pylori.
In all cases where valve problems are associated with high blood
serotonins, the daily amounts of serotonin released into the
bloodstream needed to do the nasty dead (judged by urine metabolites)
is about 50 mg a day. Which is about the standard 5-HTP dose. So if
you're taking that, and metabolizing much of it, you can theoretically
be in trouble. No carbadopa is routinely given with the stuff to block
conversion to serotonin in the liver, and B6 is asctually sometimes
given to "help" conversion in the brain (idiotically, since it just
make the problem worse in the liver-- people long ago learned they
can't do that with L-DOPA). Again, as you know, when these amino acid
analoges are decarboxylated in the liver, they are no longer
transportable into the brain by the large aryl amino acid transporter
there. So they are stuck in the system, and your lungs and other
organs have to metabolize them. Meanwhile, they wreck your pulmonary
valve.
Steve Harris, M.D.
If you don't mind, I'd like to change the title of this thread...
_________________________________________________________________
Re: 5-HTP, Tyrosine for Depression
Author: Steven B. Harris <[log in to unmask]>
Date: 1999/02/05
Forum: sci.med.nutrition
_________________________________________________________________
In <[log in to unmask]> Michael Sierchio <[log in to unmask]>
writes:
>
>"physical (Droll Troll)" wrote:
>
<snip, mine CYC>
>> but which nevertheless did not affect the conclusion: neurotoxicity
of
>> modified 5-HTP.
>
>I think the point is simple -- 5-HTP is marketed
>as "safe" and "endogenous" but turns out not to be. Why? Because
>the fermentation process produces exobiotic isomers. Substances
>that never occur except as intermediate metabolites seem tempting
>as supplements, but are fraught with problems.
And that's not the whole of it. With the help of a liver enzyme
that uses B6, 5-HTP is converted to 5-HT (serotonin) in the liver,
before it can be taken up by the brain, in an exactly analogous manner
(and using the same enzyme) as L-Dopa is destroyed (turned into
dopamine, which doesn't get into the brain) if you take too much B6 in
Parkinson's disease. Serotonin in the blood is toxic. Nature didn't
mean to you to deal with much of it. Serotonin analogues like
ergotamine and methylsergide have long been known to directly stimulate
the growth of myocytes, and produce a cell proliferative heart valve
disease thereby. Recently another serotonin analogue (fenfluramine,
the bad part of Phen-fen) was recently found to do the same. None of
which is a surprise, as people who over produce serotonin in the blood
from carcinoid tumors, or from eating high serotonin containing foods,
get the same valve disease (their serotonin metabolite excretion is
equivalent to about equal to the production from 50 mg of 5-HTP a day,
if all converted). I expect that takers of 5-HTP, especially with B6,
have a nasty surprise awaiting them one day. As usual, Pearson and
Shaw miss the REAL danger.
Steve Harris, M.D.
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