Casein-free and gluten-free diets for children with autism
What it found
In children with autism, a gluten-free and casein-free diet was linked to fewer repetitive behaviours and better cognition scores.
The authors say the evidence is promising but more research is needed.
What they found
Studies in people
Repetitive behaviours
Five studies found a small reduction in stereotypical behaviours in children on the gluten-free and casein-free diet compared with the control group.
Cognition
Three studies found a small improvement in cognition scores in children on the diet. One study may have influenced this result.
Social and communication
There was no clear difference in social or communication symptoms between the diet and control groups.
Gut symptoms
One study reported improvements in gut symptoms in the gluten-free diet group, while another found no change in abdominal pain or constipation. These were described in words rather than pooled in the analysis.
Side effects
Four studies looked at side effects and found no difference between the diet and control groups. Some children on the diet had irregular bowel movements, stomach aches, nausea, night waking or decreased appetite, but similar complaints occurred in the control group.
What the authors conclude
- They conclude that a gluten-free and casein-free diet can reduce stereotypical behaviours and improve cognition in children with autism.
- They say the benefits shown are promising, though most included studies were single-blind.
- They call for larger studies with double-blind designs and more sensitive measurements to confirm these findings.
How it was done
Families of children with autism often look for dietary approaches because standard treatments do not always help enough. The authors wanted to pool the evidence on whether a gluten-free and casein-free diet helps symptoms and whether it is safe.
They pooled 8 randomised controlled trials with 297 children with autism, comparing a gluten-free and/or casein-free diet with a normal diet. The trials lasted from 1.5 months to 12 months and took place in Iran, Norway, Poland, Spain, the USA and Denmark.
What it can’t tell you
- Most of the included studies were small and not double-blind, so the results may be affected by bias.
- The studies used different designs, participants and measurements, so the findings are not consistent across all trials.
- The long-term effects of the diet beyond 12 months are not known.
Who paid
- Authors work at
- Peking Union Medical College Hospital, China; General Hospital of Shanxi Datong Tongmei Group, China; University of California, USA
The paper
- Title
- A systematic review and meta-analysis of the benefits of a gluten-free diet and/or casein-free diet for children with autism spectrum disorder
- Type
- Systematic review and meta-analysisThe authors follow a set, published method to find every relevant study, then combine the numbers from them into one result.
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Quan L, Xu X, Cui Y, et al (2022). A systematic review and meta-analysis of the benefits of a gluten-free diet and/or casein-free diet for children with autism spectrum disorder. Nutrition reviews. doi:10.1093/nutrit/nuab073Free full textPubMed 34617108DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error