Essential amino acids in the gluten-free diet and serum in relation to depression in patients with celiac disease

PLoS One. 2015 Apr 17;10(4):e0122619. doi: 10.1371/journal.pone.0122619. eCollection 2015.


Introduction: Celiac disease (CD) is associated with an increased risk of major depressive disorder, possibly due to deficiencies in micronutrients in the gluten-free diet. We aimed to investigate whether essential amino acids (i.e., the precursors of serotonin, dopamine and other neurotransmitters) are depleted in the diet and serum of CD patients with major depressive disorder.

Methods: In a cross-sectional study we assessed dietary intake of amino acids and serum levels of amino acids, in 77 CD patients on a gluten-free diet and in 33 healthy controls. Major depressive disorder was assessed with structured interviews (using the Mini International Neuropsychiatric Interview Plus). Dietary intake was assessed using a 203-item food frequency questionnaire.

Results: Participants had a mean age of 55 years and 74% were women. The intake of vegetable protein was significantly lower in CD patients than in healthy controls (mean difference of 7.8 g/d; 95% CI: 4.7-10.8), as were serum concentrations of tyrosine, phenylalanine and tryptophan (all p < 0.005). However, within the CD patient group, the presence of major depressive disorder (n = 42) was not associated with intake or serum levels of essential amino acids.

Conclusions: Patients with CD on a long-term gluten-free diet, with good adherence, consume significantly less vegetable protein than controls, and their serum levels of several essential amino acids were also lower. Despite its potential adverse effect, intake and serum levels of essential amino acids were not related to major depression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Amino Acids, Essential / blood*
  • Body Mass Index
  • Celiac Disease / blood*
  • Celiac Disease / complications*
  • Celiac Disease / pathology*
  • Chromatography, High Pressure Liquid
  • Cross-Sectional Studies
  • Depressive Disorder, Major / complications*
  • Depressive Disorder, Major / diagnosis*
  • Diet, Gluten-Free*
  • Feeding Behavior
  • Female
  • Humans
  • Interviews as Topic
  • Male
  • Mass Spectrometry
  • Middle Aged
  • Patient Compliance
  • Surveys and Questionnaires


  • Amino Acids, Essential

Grants and funding

This project was funded by a grant from the Netherlands Science Foundation (N.W.OMaGW Vici grant # 453-06-005 to WVdD),, and grants from the Leiden University Fund (LUF) and Gratama foundation # 08.10, The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.