Table 1. Correlation Coefficients for Relationships between Protein Intake and Circulating Amino Acid Levels.
| aa | Coefficient | aa | Coefficient | aa | Coefficient |
|---|---|---|---|---|---|
| alanine | −0.617 | glutathione | −0.152 | phenylalanine | −0.016 |
| arginine | −0.553 | glycine | −0.159 | proline | −0.358 |
| asparagine | −0.498 | histidine | −0.217 | serine | −0.627 |
| aspartic acid | 0.015 | isoleucine* | 0.176* | taurine | −0.189 |
| citrulline | −0.584 | leucine* | 0.213* | threonine | −0.467 |
| cysteine | −0.170 | lysine | −0.461 | tryptophan | −0.172 |
| glutamic acid | −0.014 | methionine | −0.193 | tyrosine | −0.073 |
| glutamine | −0.346 | ornithine | −0.170 | valine* | 0.328* |
Circulating BCAA levels correlated positively with daily protein intake. In contrast, all other free amino acids correlated negatively with protein intake.
Asterisks indicate BCAAs.