Schizophrenia and amino acids in diet – it is possible to enhance treatment through nutrition?

This study presents current knowledge about the possibilities for modulating the course of schizophrenia through dietary amino acids levels. Both the results of basic research (data regarding the level of amino acids in patients’ serum) and recent clinical evidence are presented. Results based on serum amino acids levels indicate the possibility of influencing the course of schizophrenia via amino acid supply. The suggested amino acids are related primarily to dopaminergic and glutamatergic neurotransmission (L- and D-tyrosine, glutamate, gamma-aminobutyric acid, glycine, serine, aspartate, and alanine). The remaining data is too scarce to draw definitive conclusions. Clinically, in addition to the amino acids listed above, an impact of amino acids related to the synthesis of glutathione (glutamic acid, cysteine, glycine, and serine) is also possible. The third possibility, affecting not the core symptoms of schizophrenia but the accompanying ones (e.g. affective symptoms), involves regulating the levels of tryptophan and other amino acids implicated in its absorption (valine, isoleucine, leucine, and phenylalanine). While some hypothetical premises are supported by clinical data, current evidence remains limited. The presented problem certainly requires further research, including a full assessment of patients’ amino acid profiles.