A gluten- and casein- (milk protein) free diet may improve behaviour in children diagnosed with autism spectrum disorder (ASD), particularly if they had pre-existing gastrointestinal (GI) symptoms, food allergies and sensitivities.

US researchers surveyed parents of 387 children with ASD. They found improved social behaviours (language production, eye contact, attention span and social responsiveness) when their children followed a gluten- and casein-free diet. The improvements were greater if the diet was followed for at least six months. The authors suggest ASD may involve the GI tract and immune system, and the diet may make them more responsive to treatment. More research is planned.