Gluten and casein are two of the most common “diet offenders.” Gluten is a protein found in the seeds of several grains such as barley, rye, and wheat. Casein is a protein found in dairy products and other foods containing dairy or lactose.
“Gluten and casein seem to be the most immunoreactive,” Klein said. “A child’s skin and blood tests for gluten and casein allergies can be negative, but the child still can have a localized immune response in the gut that can lead to behavioral and psychological symptoms. When you add that in with autism you can get an exacerbation of effects.”
Researchers used survey data from parents to determine the effectiveness of a gluten-free, casein-free diet on children with ASD.
“Research has shown that children with ASD commonly have GI [gastrointestinal] symptoms,” said Christine Pennesi, medical student at Penn State College of Medicine. She notes that the children in their study had higher rates of GI and allergy symptoms than children without ASDs, “Some experts have suggested that gluten- and casein-derived peptides cause an immune response in children with ASD, and others have proposed that the peptides could trigger GI symptoms and behavioral problems.”
The team — which included Laura Cousino Klein, associate professor of biobehavioral health and human development and family studies — found that a gluten-free, casein-free diet was more effective in improving ASD behaviors, physiological symptoms and social behaviors for those children with GI symptoms and with allergy symptoms compared to those without these symptoms.
According to Klein, autism may be more than a neurological disease — it may involve the GI tract and the immune system.
“By adhering to a gluten-free, casein-free diet, you’re reducing inflammation and discomfort that may alter brain processing, making the body more receptive to ASD therapies.” Klein said.
“While more rigorous research is needed, our findings suggest that a gluten-free, casein-free diet might be beneficial for some children on the autism spectrum,” Pennesi said. “It is also possible that there are other proteins, such as soy, that are problematic for these children.”
Klein advises, “If parents are going to try a gluten-free, casein-free diet with their children, they really need to stick to it in order to receive the possible benefits,” she said.
“It might give parents an opportunity to talk with their physicians about starting a gluten-free, casein-free diet with their children with ASD.”