Plain language summary
Gluten is a protein found in grains such as wheat, barley and rye. For some people, gluten can cause serious health issues such as coeliac disease (CD). A growing body of research suggests that mood symptoms are associated with gluten-related disorders. The objective of this systematic review and meta-analysis was to establish whether a relationship exists between mood and gluten consumption. 13 studies were included in the meta-analysis. A gluten-free diet (GFD) significantly reduced depressive symptoms in 953 participants overall. Subgroup analyses revealed no difference in effect on mood between those with and without diagnosed CD or between those with a genetic predisposition to CD. In patients diagnosed with classical CD, a GFD resulted in a statistically significant reduction in mood symptoms, whereas the effect for silent CD patients was not significant. The authors concluded that gluten elimination may represent an effective treatment strategy for mood disorders in individuals with gluten-related disorders. Future studies should focus on gluten and mood in participants without a gut-related disorder, for example, in a population sample with depression. Finally, the level of support available to help a patient in maintaining a GFD diet over time should be carefully considered when recommending a GFD in practice.
Abstract
Gluten elimination may represent an effective treatment strategy for mood disorders in individuals with gluten-related disorders. However, the directionality of the relationship remains unclear. We performed a systematic review of prospective studies for effects of gluten on mood symptoms in patients with or without gluten-related disorders. Six electronic databases (CINAHL, PsycINFO, Medline, Web of Science, Scopus and Cochrane Library) were searched, from inception to 8 August 2018, for prospective studies published in English. Meta-analyses with random-effects were performed. Three randomised-controlled trials and 10 longitudinal studies comprising 1139 participants fit the inclusion criteria. A gluten-free diet (GFD) significantly improved pooled depressive symptom scores in GFD-treated patients (Standardised Mean Difference (SMD) -0.37, 95% confidence interval (CI) -0.55 to -0.20; p < 0.0001), with no difference in mean scores between patients and healthy controls after one year (SMD 0.01, 95% CI -0.18 to 0.20, p = 0.94). There was a tendency towards worsening symptoms for non-coeliac gluten sensitive patients during a blinded gluten challenge vs. placebo (SMD 0.21, 95% CI -0.58 to 0.15; p = 0.25). Our review supports the association between mood disorders and gluten intake in susceptible individuals. The effects of a GFD on mood in subjects without gluten-related disorders should be considered in future research.
Methodological quality
Jadad score
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Allocation concealment
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