Review Open Access Gluten-free and casein-free diets in the treatment of autism

Background: Autism is a complex psychiatric disorder characterized by three core symptoms, i.e. impairments in social interaction, restricted patterns of behavior and impairments in communication. In the framework of the “opioid excess theory”, the disorder symptoms are compared to the behavioral effects of opiates. Based on this, a possible nutritional basis of autism has been proposed, hypothesizing that certain food proteins such as gluten and casein can be transformed to opioid peptides during digestion. These peptides might eventually be able to enter the blood stream and act upon the central nervous system. As a consequence, a diet low in such proteins has been hypothesized to ameliorate the behavioral symptoms of autistic children. Objective: The scope of this review was to analyze the effects of gluten-free and casein-free (GFCF) diets on children with autism, as well as to provide information concerning additional aspects related to the GFCF diet in autism. Methods: A literature search was conducted including scientific publications up until December 2013. Search results were screened for any kind of GFCF dietary intervention as well as surveys dealing with GFCF as a treatment for autism