Per the study:
“10 of 19 amino acids (specifically, leucine, isoleucine, phenylalanine, methionine, tyrosine, alanine, cysteine, glutamine, glutamate, and aspartate) significantly reduce KYNA production at the tissue level. Five (leucine, isoleucine, phenylalanine, methionine, and tyrosine) of these 10 amino acids also reduce tissue KYN concentration, with inhibition of KYNA production reflecting these reductions in KYN uptake.”
The amino acids in my whey protien are alaine, arginine, aspartic acid, cysteine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine.
As far as I can tell from my reading, of those, typtophan would increase KYNA.
It’s not that KYNA is bad anymore than dopamine is bad, it’s probably just a matter of the correct balance.
More:
https://www.psychcongress.com/article/could-chemical-switch-ease-schizophrenia