Background: Genetic and environmental factors are both responsible for the etiology of autism spectrum disorders (ASD). Although epidemiological studies have been conducted to clarify the association between restriction diets and ASD, the conclusion remains unclear. This study was undertaken to investigate the effect of gluten free diet (GFD) on gastrointestinal symptoms and behavioral indices in children with ASD.
Methods: In this randomized clinical trial, 80 children diagnosed with ASD by the Autism Diagnostic Interview-Revised (ADI-R) were assigned into GFD (n=40) and regular diet (RD) (n=40) groups for 6 weeks. At the beginning and end of the intervention, the ROME Ш questionnaire for evaluating gastrointestinal symptoms and Gilliam Autism Rating Scale 2 questionnaire (GARS-2) for assessing psychometric properties were completed.
Results: Of the 80 children, 53.9% had gastrointestinal abnormalities. In the GFD group, the prevalence of gastrointestinal symptoms decreased significantly (P<0.05) after intake of GFD (40.57% vs. 17.10%) but increased insignificantly in the RD group (42.45% vs. 44.05%). GFD intervention resulted in a significant decrease in behavioral disorders (80.03±14.07 vs. 75.82±15.37, P<0.05) but an insignificant increase in the RD group (79.92±15.49 vs. 80.92±16.24).
Conclusion: This study suggested that GFD may be effective in controlling gastrointestinal symptoms and ASD behaviors.
Keywords: autism; behavior disorders/problems; gastrointestinal system; gluten free diet.