Improving therapeutics in anorexia nervosa with tryptophan

Life Sci. 2017 Jun 1:178:87-93. doi: 10.1016/j.lfs.2017.04.015. Epub 2017 Apr 22.


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.

Keywords: 5-HIAA (5-hydroxyindole acetic acid); 5-HTP (5-hydroxytryptophan); Anorexia nervosa; Antidepressants; Antipsychotics; Dopamine (3,4-dihydroxyphenyl ethylamine); Essential amino acid; Fluoxetine (N-methyl-3-phenyl-3-[4-(trifluoromethyl)phenoxy]propan-1-amine; GABA (gamma-aminobutyric acid); Kynurenic acid (4-hydroxyquinoline-2-carboxylic acid); Quinolinic acid (pyridine-2,3-dicarboxylic acid); Serotonin; Serotonin (5-hydroxytryptamine); Tryptophan; Tryptophan (2-amino-3-(1H-indol-3-yl) propanoic acid); Valine (2-amino-3-methylbutyric acid).

Publication types

  • Review

MeSH terms

  • Animals
  • Anorexia Nervosa / drug therapy*
  • Anorexia Nervosa / physiopathology
  • Anorexia Nervosa / psychology
  • Brain / metabolism
  • Diet / psychology
  • Dietary Supplements
  • Humans
  • Serotonin / metabolism*
  • Tryptophan / administration & dosage*
  • Tryptophan / metabolism


  • Serotonin
  • Tryptophan