Complementary and alternative treatments such as the Gluten and Casein-Free Diet (GFCF), while not recommended in national and international guidelines on autism intervention, are extremely popular among families of children with autism, with a reported use between 52% and 95%.

The GFCF diet has been promoted as a treatment for the core symptoms of autism as well as the gastrointestinal (GI) symptoms that might be present in children with autism. The unproven rationale for this treatment is that GI and behavioural symptoms of autism originate from an impaired ability to break down dietary proteins present in gluten and casein, which would results in the formation of chemicals that cross the intestinal membranes, enter the bloodstream, and damage the brain.

This hypothesis was recently tested in a number of rigorous studies, all failing to show that children with autism have “leaky guts”. While anecdotal reports have reported improvement in autism symptoms with the GFCF diet, controlled studies have been limited. Based on preliminary findings, available research data do not support the use of GFCF diet as an effective treatment for individuals with autism.

However, given the real hardships associated with implementation of a strict GFCF diet, additional studies are needed to assess risk factors and possible markers that identify individuals who might benefit from these diets. Families must consider the implications of further dietary restriction in a child who may already have a limited food repertoire. Because bone loss has been reported in children on the GFCF diet, consultation with a registered dietician is recommended before foods are eliminated from the child’s diet. Proper nutrition is as important for people with autism as it is for anyone else.

– Dr Giacomo Vivanti