Posted by Larry Hoover on December 5, 2002, at 9:44:33
In reply to Re: Supplement plan - d-,l-phenylalanine?? » Larry Hoover, posted by bluedog on December 5, 2002, at 9:10:00
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> > Natural phenylalanine is all l-. When you come across the d-,l- designation, that means it's man-made. Nature makes her biochemicals with enzymes, where the three-dimensional structure is always pre-determined. We make our chemicals in open vats, where three-dimensional structures are not controllable. Even if we wanted all l-phenylalanine, our product will always be a mixture of d- and l-, termed a racemic mixture. You can separate them out by physical means, if necessary.
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> > For a lot of nutrients, taking a racemate (i.e. d-,l-)provides only about 50% of the desired substance, because half won't be able to fit into our enzymes to be converted to other uses. This is one of the rare cases where that's a good thing, because the unnatural isomer can still be put to good use in the synthesis of PEA.
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> So just to be absolutely clear is my following summary of your advice correct?
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> l-phenylalanine is probably going to be more beneficial to my mood than l-tyrosineSort 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.
Think of a crowd trying to push through two doors. Let's say women (to represent l-Phe) can go through either door, but men (to represent d-Phe) can only go through one of the doors. A steady stream of women through their special door will reduce the number available to go through the door that both sexes can use. If purely women were in the crowd, then half could go through either door. Add men, and you get more women going through their special door, because of competition with men at the other door.
>Is it healthy to put an unnatural molecule into your body or is a molecule simply a molecule (whether natural or synthetic) and the body is smart enough to be able to deal with it without any adverse side effects?
You get d-aminos all the time. They are produced in relatively high yields by bacteria. 10% or more of the aminos in beer are d-isomers. 30% in some cheeses. It's not so much unnatural, but normal protein sources (meat, soya) are all l-.
>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.
> I suppose the analogy I would draw would be to Vitamin E supplements. Whereas dl-alpha tocopheral and d-alpha tocopheral are both beneficial to the body, the natural d isomer form is more readily useable by the body and nutritionists recommend that you look for the natural form in your supplements.You see, that's a falsehood. Natural isn't always better, although some philosophies of health make that assumption. There is no chemical reason to select natural vitamin E over synthetic. It takes no part in any metabolic process of any consequence, but instead, it just floats around. It's kind of like a sacrificial substance. It readily reacts with oxydizing substances, "killing" them before they can do damage to other essential components of our body, like DNA. There are eight isomers of tocopherol. If you're really focussed on this, take all eight, usually labelled as "mixed tocopherols".
>Are you saying that in the case of phenylalanine that the opposite is the case and 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.
> I hope you can make some sort of sense of my questions.
>
> Thanks Larry
> bluedogIf there's more, keep asking.
Lar
poster:Larry Hoover
thread:129993
URL: http://www.dr-bob.org/babble/20021203/msgs/130623.html