Graphical abstract Excessive dieting‐induced nutritional deficiency of tryptophan : Effects on behavior and efficacy of antipsychotic and antidepressant medication .
& NA ; A growing body of evidence suggests that our diet is an important contributing factor in the development , management and prevention of a number of psychiatric illnesses .
Tryptophan , an essential amino acid , is the sole precursor of neurotransmitter 5‐hydroxytryptamine ( 5‐HT ; serotonin ) .
Administration of tryptophan can boost serotonin neurotransmission to produce therapeutically important effects in serotonin deficiency disorders .
Anorexia nervosa ( AN ) an eating disorder associated with high levels of psychiatric comorbidity including psychosis , hyperactivity , depression and anxiety has highest lethality of all psychiatric illnesses .
Evidence suggests that excessive dieting and food restriction can decrease brain tryptophan and serotonin in AN patients to precipitate depression , psychosis and hyperactivity .
There are currently no FDA approved pharmacological treatments available for AN patients ; antidepressants and antipsychotics , largely used to treat associated psychiatric comorbidities are also not very effective .
The aim of this non‐ systematic review article is to evaluate and document a potential importance of tryptophan supplementation in improving therapeutics in AN patients .
Effects of normal meals rich in carbohydrates or proteins on plasma tryptophan and tyrosine ratios.
BACKGROUND The delivery of circulating tryptophan to the brain and its conversion to serotonin vary directly with plasma concentrations of tryptophan and inversely with those of other large neutral amino acids ( LNAAs ) . Although carbohydrate-rich , protein-free formula diets have been shown to elevate , and high-protein diets to depress , the tryptophan-LNAA ratio , few data are available about this ratio 's responses to actual meals . OBJECTIVE We determined whether carbohydrate-rich or protein-rich breakfasts , such as those Americans normally eat , produce substantial differences in the plasma tryptophan-LNAA ratio and in the corresponding ratio for tyrosine , the precursor of brain dopamine and norepinephrine . DESIGN Nine overnight-fasted subjects consumed , 3 - 7 d apart , a carbohydrate-rich ( 69.9 g carbohydrate and 5.2 g protein ) and a protein-rich ( 15.4 g carbohydrate and 46.8 g protein ) breakfast . Blood sample s collected at baseline and after 40 , 80 , 120 , and 240 min were assayed for tryptophan , tyrosine , the 5 other LNAAs , and insulin . RESULTS The carbohydrate-rich and protein-rich breakfasts had significantly different effects on both the plasma tryptophan-LNAA and tyrosine-LNAA ratios ( each P < 0.01 ) . Among the 8 subjects who consumed both breakfasts , the median difference for tryptophan : LNAA was 54 % ( range : 36 - 88 % ) and for tyrosine : LNAA was 28 % ( range : 10 - 64 % ) . Insulin concentrations rose significantly after the carbohydrate but not after the protein meal . CONCLUSIONS High-carbohydrate and high-protein breakfasts similar to those Americans normally eat can cause substantial differences in the plasma tryptophan ratio and thus , probably , in brain tryptophan concentrations and serotonin synthesis . Such meals also change the plasma tyrosine ratio and may thereby modify catecholamine synthesis
Graphical abstract Excessive dieting‐induced nutritional deficiency of tryptophan : Effects on behavior and efficacy of antipsychotic and antidepressant medication .
& NA ; A growing body of evidence suggests that our diet is an important contributing factor in the development , management and prevention of a number of psychiatric illnesses .
Tryptophan , an essential amino acid , is the sole precursor of neurotransmitter 5‐hydroxytryptamine ( 5‐HT ; serotonin ) .
Administration of tryptophan can boost serotonin neurotransmission to produce therapeutically important effects in serotonin deficiency disorders .
Anorexia nervosa ( AN ) an eating disorder associated with high levels of psychiatric comorbidity including psychosis , hyperactivity , depression and anxiety has highest lethality of all psychiatric illnesses .
Evidence suggests that excessive dieting and food restriction can decrease brain tryptophan and serotonin in AN patients to precipitate depression , psychosis and hyperactivity .
There are currently no FDA approved pharmacological treatments available for AN patients ; antidepressants and antipsychotics , largely used to treat associated psychiatric comorbidities are also not very effective .
The aim of this non‐ systematic review article is to evaluate and document a potential importance of tryptophan supplementation in improving therapeutics in AN patients .