Food allergy and autism spectrum disorders: is there a link?

Gastrointestinal (GI) symptoms are common comorbidities in children with autism spectrum disorders (ASDs). Parents often attribute these GI symptoms to food allergy (FA), although an evaluation for IgE-mediated FA is often unrevealing. Our previous studies indicated a high prevalence of non-IgE-mediated FA in young children with ASDs. Therefore, non-IgE-mediated FA may account for some but not all GI symptoms observed in children with ASDs. This raises the question of what treatment measures are applicable to ASD children with GI symptoms. A wide variety of dietary supplements and dietary intervention measures for ASD children have been promoted by medical professionals practicing complementary and alternative medicine despite the lack of rigorous scientific validation in most instances. This review summarizes possible (or proposed) etiologies of GI symptoms in ASD children and discusses risks and possible benefits of intervention measures promoted by complementary and alternative practitioners, with emphasis on FA.