Posted by bluedog on December 6, 2002, at 1:55:09
In reply to Re: Supplement plan - d-,l-phenylalanine??, posted by Larry Hoover on December 5, 2002, at 9:44:33
> > So just to be absolutely clear is my following summary of your advice correct?
> >
> > l-phenylalanine is probably going to be more beneficial to my mood than l-tyrosine?
>
> Sort of. You'll get more dopamine from a given amount of tyrosine than phenylalanine, because not 100% of Phe is converted to Tyr. However, the Phe can go to PEA, which has an independent mood effect.
>
>
> but d-,l-phenylalanine is the preferable form of phenylalanine to supplement with because the synthetic isomer can be used by the body to synthesise the feel good chemical PEA?
>
> The d-isomer cannot go to Tyr, so it is wholly available for other uses.
>
> > I therefore assume that the natural l-phenylalanine is not able to be utilised by the body to synthesise PEA?
>
> No, it can go to PEA, but the d-isomer will compete for the opportunity, actually enhancing the amount of the l-isomer going to Tyr.
>
>
> >In other words would this create a pharmaceutical drug effect in my body rather than a natural food effect?
>
> You're enhancing one particular outcome, but not as a drug would do. The enzyme that makes PEA is not specific to l-phenylalanine, whereas the one to Tyr is.
>
>
> >Are you saying that in the case of phenylalanine that...the dl form is actually the more beneficial supplement to take?
>
> ONLY BECAUSE IT HAS A TENDENCY TO PRODUCE ABOUT AS MUCH PEA AS TYROSINE.
>
LarryWhen I read my above questions and your answers I seem to see some sort of circular reasoning happening.
You say that dl-Phenylalanine is preferable to take to l-tyrosine because the d-isomer is used to produce to PEA. The l-isomer can be used to produce both PEA and l-tyrosine. Then you say in your last statement that dl-phenylalanine has a tendency to produce about as much PEA as l-tyrosine!!!
My interpretation of this is that both dl-phenylalanine and l-tyrosine are used to produce similar amounts of PEA but that with dl-phenylalanine there is an additional step involved in that the l-isomer is converted to l-tyrosine before the body then uses this l-tyrosine to produce PEA.
This brings me back to my original question which is why is it more beneficial to take dl-phenylalanine instead of l-tyrosine? My simplistic understanding of the above process is that l-tyrosine will produce the "similar amount" of PEA you mentioned a lot faster than the dl-phenylalanine because you avoid the additional step of the l-phenylalanine having to be converted to l-tyrosine.
You also say that you'll get more dopamine from l- tyrosine than from phenylalanine. Does the answer to my question lie buried somewhere in this distinction? Is it more beneficial to have a higher ratio of PEA to Dopamine rather than the other way around (ie a higher ratio of Dopamine to PEA? Can you see what I'm getting at?
Here's my New summary and again correct me if I'm wrong!!
1.Both dl-phenylalanine and l-tyrosine will produce a similar amount of PEA.
2.However l-tyrosine will produce a greater amount of dopamine because with the dl-phenylalanine only the l-isomer is available to produce l-tyrosine which will in turn produce dopamine whereas the d-isomer is only able to produce PEA.
3. Therefore l-tyrosine will give you a higher ratio of dopamine to PEA in the brain: and
4. dl-phenylalanine will give you a higher ratio of PEA to dopamine in the brain.OR is this merely a matter of working out comparative dosages?????
Thanks for your patience
bluedog
poster:bluedog
thread:129993
URL: http://www.dr-bob.org/babble/20021203/msgs/130727.html