Surprisingly, a carbohydrate-only meal provides an immediate, drastic increase in serotonin biosynthesis. A high protein meal does not. And it's probably pretty

Surprisingly, a carbohydrate-only meal provides an immediate, drastic increase in serotonin biosynthesis. A high protein meal does not. And it's probably pretty irrelevant to clinical stuff because there have to be high protein meals in the past to get the effect. The reasons are: - Trp transport into CNS is rate limited by large neutral amino acid (LNAAt) transporter - Trp has a lower affinity for LNAAt than other amino acids - Trp, 5HTP, serotonin are strongly buffered by blood plasma proteins So, with a high protein meal, the isoleucine, phenylalanine etc. are outcompeting typtophan at getting into the brain. With a low protein meal, insulin triggers uptake of amino acids into tissue (again, preferentially stuff that's not Trp), and Trp in blood is enriched as it dissociates from plasma proteins. Then the composition of blood amino acids is mostly Trp so it is taken up by brain tissue. [0] https://www.ncbi.nlm.nih.gov/pubmed/22677921 https://www.ncbi.nlm.nih.gov/pubmed/22677921 [1] http://wurtmanlab.mit.edu/static/pdf/1001.pdf http://wurtmanlab.mit.edu/static/pdf/1001.pdf