Autism or autism spectrum disorder (ASD) is likely caused by a combination of genetic and environmental factors. More common in boys, those with autism exhibit challenges in social skills, speech and communication difficulties, and often display repetitive behaviors. It affects approximately 1 in 68 children in the U.S. “While children with autism frequently have gastrointestinal complaints, to date, autism has not been associated with a higher frequency of celiac disease than the general population in large studies,” notes Dr. Leonard. However, there remains intense interest in the gluten-free, casein-free (GFCF) diet as a potential treatment.
In 2016, a group of researchers conducted a small, double-blind study to determine potential benefits of the GFCF diet in children with autism. Study participants ate a GFCF diet for four to six weeks. After this initial period, they were assigned to receive either GFCF or gluten/casein-containing snacks and meals for the next 12 weeks. Because the study was double-blinded, neither the researchers nor the parents/caregivers knew which children were receiving the GFCF food so that there was no influence on expectations. Parents were asked to keep detailed records of behavior, bowel movements and sleep patterns. Researchers found no significant differences between the two groups, although they did note that the study had a small number of participants and that larger, similarly double-blinded studies are needed to confirm the results.
“We still have a lot to learn about autism, non-celiac gluten sensitivity and intestinal permeability,” states Leonard. “It seems likely that different factors contribute to the development of autism and therefore different subsets of children with autism may respond to different interventions. Some may respond to the GFCF diet, but until we can understand these subsets of children with autism, it will be difficult to predict which intervention is best for each child.”
Adopting the GFCF diet
Parents interested in trying the GFCF diet shouldn’t go it alone, advises Leonard. “I suggest that they see their primary care physician or a gastroenterologist so [the child] can be evaluated clinically with blood testing for celiac disease. I would then recommend that they meet with a registered dietitian nutritionist (RDN) to discuss how to initiate a gluten-free or gluten-free, casein-free diet while ensuring their child is still getting the proper nutrients and calories for growth.”
Leonard encourages parents to reevaluate the effectiveness of the diet after a few weeks. “I would suggest meeting with the physician before and after a trial period of two to six weeks, to discuss whether the goals of the diet were met. Then the family and physician can discuss together whether they should continue with a long-term trial of the diet or if social difficulties or nutritional deficiencies outweigh the benefits of continuing.”
Amy Keller, MS, RD, LD, is a dietitian and celiac support group leader from Bellefontaine, Ohio.