Gluten, autism and the gluten-free diet in children
What it found
A modest link exists between autism and coeliac disease, and some children with autism have signs of poor gluten digestion.
Trials of the gluten-free diet in autism have given mixed results and cannot yet show a clear benefit.
What they found
Studies in people
Autism and coeliac disease
Several large studies found a modest link between autism and coeliac disease. A Swedish study of 19,189 people diagnosed with coeliac disease as children found they were more likely to later be diagnosed with autism. A meta-analysis found that people with coeliac disease were more likely to have autism, but people with autism were not more likely to have coeliac disease.
Gut symptoms in autism
Children with autism are more likely to have gut symptoms such as abdominal pain, constipation and diarrhoea than typically developing children. A large study of 499 children with autism found higher rates of eight gut outcomes compared to controls.
Gluten antibodies in autism
Some children with autism have raised levels of antibodies against gliadin, a gluten protein, even without coeliac disease. One study found that children with autism and regression more often had a family history of coeliac disease or inflammatory bowel disease.
Trials of gluten-free diets
Of 13 randomised trials, 6 found some improvement in behaviour or thinking, 6 found no difference, and 1 found worse gut symptoms. Most trials were small, short, and not blinded, and many tested a gluten-free and casein-free diet together, so the effect of gluten alone is unclear.
How many try the diet
Adoption of gluten-free or gluten-free and casein-free diets is high among children with autism, with estimates from 10% to over 50%. Parents often report dramatic improvements, but these are anecdotal.
Nutrition on the diet
Some studies found children on a gluten-free and casein-free diet had higher intakes of some vitamins and minerals, while others found lower intake of nutrients like calcium and tryptophan. Overall the nutritional impact seems slight, but a balanced diet is still needed.
What the authors conclude
“However, a negative effect of gluten ingestion in ASD has not been proved.”
Also in their conclusions
- They say that a negative effect of gluten in autism has not been proved.
- They call for a well-powered, long-duration, placebo-controlled trial of the gluten-free diet in autism.
- They advise that further research is warranted because adoption of gluten-free diets is very high among people with autism.
How it was done
Many specialist diets have been suggested for autism, and gluten has received particularly close attention as a possible trigger. Caregivers and clinicians are unsure whether children with autism should go gluten-free, so the authors wanted to look specifically at the interaction between autism and gluten.
The authors searched a medical database for original research on autism and gluten-related disorders, the gluten-free diet in autism, or other links between autism and gluten. They found 237 articles, read the abstracts, and included 79 that met their criteria. They then grouped and discussed these papers by theme.
What it can’t tell you
- Most studies looked only at children, so the findings may not apply to adults with autism.
- The trials of the gluten-free diet were mixed and often not blinded, so they cannot show whether the diet itself causes any improvement.
- A link between autism and coeliac disease does not prove that gluten causes or worsens autism.
Who paid
- Conflicts
- The authors declare no conflict of interest.
- Authors work at
- University of Sheffield/INSIGENO, UK
The paper
- Title
- Gluten and Autism Spectrum Disorder
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Croall ID, Hoggard N, Hadjivassiliou M (2021). Gluten and Autism Spectrum Disorder. Nutrients. doi:10.3390/nu13020572Free full textPubMed 33572226DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error