The synthesis of dopamine in the body goes
protein----> phenylalanine ----> levodopa ----> dopamine
Since dopamine can't pass the BBB, we take levodopa.
But long term side effects mean dyskinesia etc.
Therefore why not take phenylalanine??
Well, being a white rat, I tried it a year ago but it did not switch me on.
Maybe I had too low a dose, I don't know. So I dropped the idea.
However, the report below suggests that it works.
Any ideas? Girija, what do you think?
Ron

Brain Food: Nuts! (Part 1) | Nutrition Wonderland
By Christie Wilcox
Almonds contain phenylalanine, which unlike other compounds crosses the blood-brain barrier easily, and has been shown to alleviate Parkinson's Disease and boost the neurotransmitters dopamine and adrenaline. ...
Nutrition Wonderland - http://nutritionwonderland.com/

Hello Ron:
If phenylalanine converts to levodopa > dopamine , why do you expect that it is different from taking levodopa in terms of benifits and side effects?

Hi Imark3000,
I have no evidence to say it will be any improvement on levodopa. I just thought it was worth trying, to see if there were fewer side effects, taking the precurser of levodopa, instead of levodopa itself. Phenylalanine like levodopa passes the BBB, and the report in my first post claims it "has been shown to alleviate Parkinson's Disease and boost the neurotransmitters dopamine and adrenaline". I wondered whether it was a more controlled and natural process if the brain manufactured the levodopa, rather than being fed it from a chemical factory material.
A healthy person starts the eynthesis with protein. Starting the in brain process with phenylalanine is only one step away from that. Using levodopa is 2 steps away.
Ron

1: J Nutr. 2007 Jun;137(6 Suppl 1):1539S-1547S; discussion 1548S.

Tyrosine, phenylalanine, and catecholamine synthesis and function in the brain.

Fernstrom JD, Fernstrom MH.

Department of Psychiatry, University of Pittsburgh School of Medicine,
Pittsburgh, PA 15213, USA. fernstromjd@upmc.edu

Aromatic amino acids in the brain function as precursors for the monoamine
neurotransmitters serotonin (substrate tryptophan) and the catecholamines
[dopamine, norepinephrine, epinephrine; substrate tyrosine (Tyr)]. Unlike almost
all other neurotransmitter biosynthetic pathways, the rates of synthesis of
serotonin and catecholamines in the brain are sensitive to local substrate
concentrations, particularly in the ranges normally found in vivo. As a
consequence, physiologic factors that influence brain pools of these amino acids,
notably diet, influence their rates of conversion to neurotransmitter products,
with functional consequences. This review focuses on Tyr and phenylalanine (Phe).
Elevating brain Tyr concentrations stimulates catecholamine production, an effect
exclusive to actively firing neurons. Increasing the amount of protein ingested,
acutely (single meal) or chronically (intake over several days), raises brain Tyr
concentrations and stimulates catecholamine synthesis. Phe, like Tyr, is a
substrate for Tyr hydroxylase, the enzyme catalyzing the rate-limiting step in
catecholamine synthesis. Tyr is the preferred substrate; consequently, unless Tyr
concentrations are abnormally low, variations in Phe concentration do not affect
catecholamine synthesis. Unlike Tyr, Phe does not demonstrate substrate
inhibition. Hence, high concentrations of Phe do not inhibit catecholamine
synthesis and probably are not responsible for the low production of
catecholamines in subjects with phenylketonuria. Whereas neuronal catecholamine
release varies directly with Tyr-induced changes in catecholamine synthesis, and
brain functions linked pharmacologically to catecholamine neurons are predictably
altered, the physiologic functions that utilize the link between Tyr supply and
catecholamine synthesis/release are presently unknown. An attractive candidate is
the passive monitoring of protein intake to influence protein-seeking behavior.

PMID: 17513421 [PubMed - indexed for MEDLINE]

Thanks Rick for the article, it reminded me I forgot to put tyrosine in the sequence. I did my first post from memory at 6-00am!!
The full sequence is.
protein---->phenylalanine---->tyrosine---->levodopa---->dopamine

Phenylalanine, tyrosine and levodopa are all amino acids, but differ by the number of hydroxyl groups on the aromatic ring.
I originally tried phenylalanine since it is readily available in UK health shops. I did not find tyrosine. Surely someone somewhere has tried this before, with either phenylalanine or tyrosine, even on animal testing.
Ron

Ron,
This is my guess. I think phenylalanine when accumulated or in excess in the blood is toxic to body as seen in PKU patients. I suspect drug developers didnt want to take a chance with Phe and the next step in biosynthesis seemed good enough.
to read more please go to
http://www.nature.com/jcbfm/journal/v18/n11/index.html
© 2009 International Society for Cerebral Blood Flow & Metabolism

This is true for me, I'm allergic to the stuff and it causes, within minutes of ingestion, blinding headache, intense nausea, and diarhea or however you spell that awful word. I have read some with more severe reactions can faint or worse. But surely there is a test that could be done, ahead of time, to weed out people like me? And I know that I am not the norm, that is, the vast majority of people do not have a problem with phenalanaline, so they should be able to easily find enough subjects to test this theory on that would not have a problem with metabolizing the phenalanaline. I guess the point is, how many PWP can there be that also cannot properly metabolize phenalanaline? I would think not so many that they could not do a study like Ron is suggesting.

Good Morning lurkingforacure,
There are tests available to see if you cannot metabolize Phenylalanine. Please check with your doctor. THe classical disorder is called PKU and it is a genetic disorder. see the links below (wikipedia links).
I have not checked to see if there are any publications about this and PWPs
I will check.
Links:
#
Phenylalanine (abbreviated as Phe or F) is an α-amino acid with the formula HO2CCH(NH2)CH2C6H5, which is found naturally in the breast milk of mammals and ...
en.wikipedia.org/wiki/Phenylalanine - Cached - Similar pages
#
Phenylalanine hydroxylase - Wikipedia, the free encyclopedia
Phenylalanine hydroxylase is the rate-limiting enzyme of the metabolic pathway which degrades excess phenylalanine. The other substrates in the reaction are ...
en.wikipedia.org/wiki/Phenylalanine_hydroxylase - Cached - Similar pages


Girija

This is interesting information. Check it out!


Parkinson's Disease, Michael Fox, MS And The Aspartame Story
Dr. Roberts goes in depth about aspartame and Parkinson's Disease. ... The enzyme phenylalanine hydroxylase converts phenylalanine to tyrosine. ...
www.rense.com/general21/parkinsonFox.htm - Cached - Similar pages
#
Parkinson's disease and

I've been taking tyrosine for the past 9 months, and enjoy a daily handful or two of almonds. Don't know whether these two, in combination, are helping slow the progression, but so far, 3 years after dx and 4 years after first symptoms, I've not had to take any medications (sinemet, etc).

I do wish that almonds had a lower fat content -- urp.

Jon