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Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 10 of 10. This is the beginning of the thread.
Posted by Francesco on October 31, 2003, at 13:38:04
I found what follows on an italian article.
Se la tirosina viene assunta con carboidrati complessi e quindi a medio-basso indice glicemico, i livelli dell'aminoacido possono incrementare in modo significativo, in quanto si abbassano i livelli degli aminoacidi competitori della tirosina. Un pasto solo proteico, pur innalzando i livelli serici di tirosina, non sembra far aumentare tuttavia la sintesi dei neurotrasmettitori
It says that if you take tyrosine with complex carboidrates (pasta and so on) this leads to an increase of the dopamine and NE, because complex carboidraites lowers at the same time the level of the competitor aminoacids. But if you take it with protein this doesn't result in an increase of dopamine and NE (even if the level of tyrosine gets higher).
Have some of you heard before something like this ?
Posted by Ame Sans Vie on October 31, 2003, at 15:27:05
In reply to L-tyrosine with carbo or proteins ? , posted by Francesco on October 31, 2003, at 13:38:04
Yeah, L-tyrosine is quite competitive with other aminos, so protein should absolutely not be eaten within a few hours of taking it. Every resource I've personally come across insists that it must be taken on an empty stomach.
Posted by Francesco on November 1, 2003, at 4:40:10
In reply to Re: L-tyrosine with carbo or proteins ? » Francesco , posted by Ame Sans Vie on October 31, 2003, at 15:27:05
what do you mean by empty stomach ? I mean ... how much after can I eat ? about the protein vs carbo: reading what I read it seems that if you take tyrosine you should take more carbo but if you have adhd inhattentive type you should take more proteins. what's the solution of the dylemma ?
Posted by DSCH on November 1, 2003, at 10:06:54
In reply to Re: L-tyrosine with carbo or proteins ? » Ame Sans Vie, posted by Francesco on November 1, 2003, at 4:40:10
> what do you mean by empty stomach ? I mean ... how much after can I eat ? about the protein vs carbo: reading what I read it seems that if you take tyrosine you should take more carbo but if you have adhd inhattentive type you should take more proteins. what's the solution of the dylemma ?
Some people say that for optimum effect take the tyrosine in the morning before breakfast and wash it down with some orange juice or other fruit juice to get a rise in blood insulin, which supposedly aids uptake across the BBB (I have read that only assists tryptophan though).
Posted by Larry Hoover on November 1, 2003, at 11:36:30
In reply to L-tyrosine with carbo or proteins ? , posted by Francesco on October 31, 2003, at 13:38:04
> I found what follows on an italian article.
>
> Se la tirosina viene assunta con carboidrati complessi e quindi a medio-basso indice glicemico, i livelli dell'aminoacido possono incrementare in modo significativo, in quanto si abbassano i livelli degli aminoacidi competitori della tirosina. Un pasto solo proteico, pur innalzando i livelli serici di tirosina, non sembra far aumentare tuttavia la sintesi dei neurotrasmettitori
>
> It says that if you take tyrosine with complex carboidrates (pasta and so on) this leads to an increase of the dopamine and NE, because complex carboidraites lowers at the same time the level of the competitor aminoacids. But if you take it with protein this doesn't result in an increase of dopamine and NE (even if the level of tyrosine gets higher).
>
> Have some of you heard before something like this ?Your quotation describes a process that contradicts my understanding of what happens.
Tyrosine is one of five amino acids that compete for transport into the central nervous system (across the so-called blood/brain barrier), via the LNAAT (Large Neutral Amino Acid Transporter). If I recall correctly, the five are tyrosine, phenylalanine, leucine, isoleucine, and tryptophan. They each have slightly different affinities for the transporter, so if found in the blood at equal concentrations, the one(s) with the higher affinity will have an advantage, and be transported into the brain more efficiently. Tryptophan has the lowest affinity of the five, and it is found in relatively low concentrations in all proteins, so it tends to lose the competition relative to the others.
What you want to do, to increase the availability of a particular amino acid to the brain, is control the relative concentrations of the aminos in the blood.
One of the ways to do that is to consume a pure amino acid product. If taken on an empty stomach (four hours after a meal, but best in the morning at least one half hour before breakfast, due to the fasting that occurs during sleep), it stands to reason that a pure amino will have substantial uptake from the stomach (it is "predigested"). It will thus be in substantially higher blood concentration than any other aminos, as they have already been removed from the blood by tissues which require them during the fasting stage between meals. It's like a busload of people entering a fast food restaurant at the same time. Other people entering the restaurant at the same time are going to have a harder time getting service. You want to flood the transporter, so it really doesn't have much "choice" about which amino it will pump into the brain.
Now, about the carbo thingie. Insulin regulates more than blood sugar. It also regulates amino acid uptake by muscles. When insulin goes up, muscles take up glucose *and* amino acids, but with one exception. Muscles don't need much tryptophan. Tryptophan concentrations stay stable, while the others go down. So, my understanding is that carb intake will *reduce* tyrosine availability to the brain, while simultaneously enhancing tryptophan availability. Dopamine and norepinephrine lose, serotonin wins.
That is one of the theories behind carb craving by depressives.....an intuitive attempt at self-medication, via promotion of tryptophan uptake by the brain.
I'm not saying I'm right.....just be careful of things you read. Find confirmation of *any* advice you may receive, including mine.
Lar
Posted by DSCH on November 3, 2003, at 12:19:59
In reply to Re: L-tyrosine with carbo or proteins ? » Francesco , posted by Larry Hoover on November 1, 2003, at 11:36:30
> Tyrosine is one of five amino acids that compete for transport into the central nervous system (across the so-called blood/brain barrier), via the LNAAT (Large Neutral Amino Acid Transporter). If I recall correctly, the five are tyrosine, phenylalanine, leucine, isoleucine, and tryptophan. They each have slightly different affinities for the transporter, so if found in the blood at equal concentrations, the one(s) with the higher affinity will have an advantage, and be transported into the brain more efficiently. Tryptophan has the lowest affinity of the five, and it is found in relatively low concentrations in all proteins, so it tends to lose the competition relative to the others.
Larry, do you know what the brain does with leucine and isoleucine?
Posted by Larry Hoover on November 3, 2003, at 14:59:45
In reply to LNAAT: leucine and isoleucine » Larry Hoover, posted by DSCH on November 3, 2003, at 12:19:59
> > Tyrosine is one of five amino acids that compete for transport into the central nervous system (across the so-called blood/brain barrier), via the LNAAT (Large Neutral Amino Acid Transporter). If I recall correctly, the five are tyrosine, phenylalanine, leucine, isoleucine, and tryptophan. They each have slightly different affinities for the transporter, so if found in the blood at equal concentrations, the one(s) with the higher affinity will have an advantage, and be transported into the brain more efficiently. Tryptophan has the lowest affinity of the five, and it is found in relatively low concentrations in all proteins, so it tends to lose the competition relative to the others.
>
> Larry, do you know what the brain does with leucine and isoleucine?This is exactly why I like questions so much. I haven't a clue what the answer is. But I'm going to find out.
Lar
Posted by DSCH on November 3, 2003, at 17:57:38
In reply to Re: LNAAT: leucine and isoleucine » DSCH, posted by Larry Hoover on November 3, 2003, at 14:59:45
Posted by Larry Hoover on November 4, 2003, at 9:27:04
In reply to Glad I asked that question, then ;-) (nm) » Larry Hoover, posted by DSCH on November 3, 2003, at 17:57:38
Valine also uses the same transporter, so there are six, not five, competitors. Gabapentin and other drugs will compete for it, as well.
Anyway, leucine and isoleucine seem to serve structural roles in specialized proteins, and modulate the activity of receptors such as GABA(A) and GABA(B), NMDA, and NA.
Most people have no problem getting an adequate supply of these aminos, but disturbances in proportions of these six aminos are associated with certain pathologies....Alzheimer's, schizophrenia, mania, depression, OCD.
It's hard to get a clear picture of what leucine and isoleucine do.
Lar
Posted by DSCH on November 4, 2003, at 13:03:03
In reply to Re: Glad I asked that question, then ;-) » DSCH, posted by Larry Hoover on November 4, 2003, at 9:27:04
> Valine also uses the same transporter, so there are six, not five, competitors. Gabapentin and other drugs will compete for it, as well.
>
> Anyway, leucine and isoleucine seem to serve structural roles in specialized proteins, and modulate the activity of receptors such as GABA(A) and GABA(B), NMDA, and NA.
>
> Most people have no problem getting an adequate supply of these aminos, but disturbances in proportions of these six aminos are associated with certain pathologies....Alzheimer's, schizophrenia, mania, depression, OCD.Hmmmm... proteins glom up into plaques that kill cells in Alzheimer's (also Huntington's Chorea IIRC). But those proteins are glutamine heavy are they not?
The prion brain diseases (Fatal Familial Insomnia, CJD, etc.) are somewhat similar, but with those there appears to be a folding autocatalysis that makes the disease progression far more rapid.
> It's hard to get a clear picture of what leucine and isoleucine do.
>
> LarKinda makes me glad I've dropped precursor loading for TMG.
This is the end of the thread.
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