Paul Whiteley, Jacqui Rodgers, Dawn Savery, Paul Shattock
The opioid-excess hypothesis of autism suggests that autism is the consequence of the incomplete breakdown and excessive absorption of peptides with opioid activity (derived from foods which contain gluten and casein), causing disruption to biochemical and neuroregulatory processes. Biochemical evidence has indicated the presence of increased levels of peptides in the urine of people with autism, and previous behavioural studies have demonstrated a connection between the long term exclusion of gluten and casein from the diet and improvements in the behaviour of some children with autism. The introduction of a gluten-free diet to children with autism and associated spectrum disorders (n = 22) was monitored over a 5 month period using a battery of parental and teacher interview/questionnaire sessions, observation reports, psychometric tests and urinary profiling. Results suggested that participants on a gluten-free diet showed an improvement on a number of behavioral measures. However there was no significant decrease in specific urinary compounds excreted when compared with controls and a gluten challenge group.