The Effects of a Gluten-Free/Casein-Free Diet on Behavioral Indices in Children with Autism Spectrum Disorder: A Systematic Review and Meta-Analysis

Introduction: Autism is a neurological disorder that has seen an increase in prevalence in recent years. It is hypothesized that diet may influence mental health and improve the behavioral symptoms of autism. Objectives: The purpose of this study is to examine the effects of gluten-free and casein-free diets on children with autism. Data Sources: International databases such as Google Scholar, PubMed, Cochrane, and Science Direct were searched using keywords including Autism, Gluten-free, Casein, Diet, and Autistic Disorder, without any time restriction Study Selection: Ultimately, 8 articles were selected for the final analysis. Data Extraction: The study revealed that gluten-free/casein-free (GF/CF) diets had a significantly positive effect on the behavior index of autistic children. In terms of the behavior index, the effect size was a standard mean difference (SMD) of -0.27 (P = 0.001) with a 95% confidence interval (CI) of -0.424 to -0.116. A meta-analysis comparing intervention and control groups indicated that the GF/CF diet had an effect size of SMD = -0.27 (P = 0.001) with a 95% CI of -0.429 to -0.112 on the behavior index. Results: The results of these studies were synthesized using the fixed effects model of meta-analysis with STATA version 14. Conclusions: Given the positive impact of the GF/CF diet on improving the behavior of autistic children, this dietary approach can be considered as a means to enhance behavioral symptoms in these children.