Is the gluten-free and casein-free diet efficacious in the treatment of childhood autism spectrum disorder?

Abstract

Autism spectrum disorder (ASD) is a set of heterogeneous neurodevelopmental conditions, characterized by early-onset difficulties in social communication as well as repetitive and unusually restricted behaviors and interests. The treatment of ASD is based primarily on psychoeducational and behavioral interventions. Since the effectiveness of available treatments for ASD is limited, many families search for alternative therapies, such as the gluten-free and casein-free (GFCF) diet. Despite the popularity of the GFCF diet as a supplementary treatment in children with ASD, several rigorous evaluations have failed to confirm its effectiveness. The majority of the available studies examining the efficacy of the GFCF diet are seriously flawed and allow no firm conclusions. The available evidence regarding the effectiveness of the GFCF diet in the treatment of childhood ASD is very weak and cannot be considered promising. The GFCF diet should be used only if an allergy or intolerance to nutritional gluten or casein has been established. The identification of a hypothetical diet-related ASD phenotype may help in selecting children who could benefit from a GFCF dietary intervention. An important consideration is that potentially ineffective therapies may imply considerable opportunity costs, with other possibly more effective treatment approaches remaining unutilized.