Phenylalanine intolerance

[Lou]

While I don't have phenylketonuria(PKU), a genetic disorder, I did develop an intolerance to phenylalanine after getting ME/cfs. Even a small amount found in many sugarless gums and mints give me almost instant brain fog.

Any ideas as to cause?

Thanks,

 

[richvank]

While I don't have phenylketonuria(PKU), a genetic disorder, I did develop an intolerance to phenylalanine after getting ME/cfs. Even a small amount found in many sugarless gums and mints give me almost instant brain fog.

Any ideas as to cause?

Thanks,

Hi, Lou.

I think that's interesting. As you may know, phenylalanine is an essential amino acid, and one of its uses in the body is to be converted to tyrosine, which in turn is the raw material for making dopamine, norepinephrine, and epinephrine (adrenaline). The conversion of phenylalanine to tyrosine requires BH4 (tetrahydrobiopterin). BH4 is also needed for the conversion of tyrosine to L-dopa in the pathway toward making dopamine. BH4 is also needed to convert tryptophan to 5-HTP in the pathway for making serotonin and melatonin.

BH4 is often depleted in ME/CFS because it is linked to the folate metabolism, and this metabolism is dysfunctional because it is linked to the methylation cycle by the methionine synthase reaction, and also because it is oxidized by peroxynitrite, which rises in ME/CFS because of glutathione depletion.

I suggest that what happens when you take phenylalanine is that it uses too much of your limited supply of BH4, and that takes BH4 away from the other reactions needed to produce your neurotransmitters. The levels of one or more of your neurotransmitters drops, and that produces the brain fog.

Best regards,

Rich

 

[Lou]

Hi Rich,

Thanks very much for this explanation, and it makes perfect sense. You'd think more of us would have this complaint since BH4 depletion is common in ME/cfs. Perhaps, my BH4 supply is extremely low. Am wondering if supplementation with biopterin could posssibly help, or is it better staying the course with simplified methylation despite my particular sensitivities to the protocol.

 

[richvank]

Hi Rich,

Thanks very much for this explanation, and it makes perfect sense. You'd think more of us would have this complaint since BH4 depletion is common in ME/cfs. Perhaps, my BH4 supply is extremely low. Am wondering if supplementation with biopterin could posssibly help, or is it better staying the course with simplified methylation despite my particular sensitivities to the protocol.

Hi, Lou.

It's difficult to be sure without running the Yasko SNP panel, but given how you react to phenylalanine supplementation, I think it is likely that you are low in BH4. and have the MTHFR A1298C polymorphism. As you may know, it used to be possible to order BH4 from Switzerland, but the FDA has put the kybosh on that since they have approved the synthetic drug form, Kuvan, which of course requires a prescription and is expensive. Amy Yasko has developed a workaround supplement that does contain biopterin, as you mentioned, together with some other things. You might consider adding that. It can be found here: http://www.holisticheal.com/mthfr-a1298c-liver-support-bh4-function.html

Best regards,

Rich