For decades, the gluten-free, casein-free diet (GF/CF diet) has been a popular approach by parents attempting to improve the cognitive and behavioral symptoms of their childrens’ autism. This approach has been bolstered by anecdotal reports from parents and celebrities that avoiding gluten and/or casein–the proteins found in wheat, barley, rye and milk, respectively–may help improve symptoms of people living with autism.
Some (but not all) research suggests that one feature of autism spectrum disorders is reduced enzymatic activity and increased permeability of the intestinal barrier, both of which can lead to potential gastrointestinal problems. Given these digestive disorders, one prevailing theory holds that ingestion of gluten or casein might result in incomplete digestion, in turn causing large, undigested proteins to leak out of the gut and travel to the brain, where they could eventually interfere with neuro-receptors and cause autistic symptoms. Therefore, it was believed that in susceptible autistic patients, a gluten-free/casein-free diet might produce direct improvements in brain function. To date, research on the topic has been very contradictory and characterized by small, poorly-designed studies.
Recently, however, researchers conducted a systematic review of 14 research articles related to dietary changes in patients with autism; specifically, the effects of gluten-free or casein-free diets on those with autism. After reviewing the articles, which covered 188 patients between the ages of 2 and 17, they deduced a “limited and weak” connection between a diet low in gluten or casein and brain function in those with autism, suggesting a different factor may be to blame for any observed behavioral changes after dietary restrictions were imposed.
So how does this recent study account for some patients’ reported changes in mood and behavior on the GF/CF diet? Simple allergies and food intolerance, according to researchers.
“Should a child with autism spectrum disorder (ASD) experience acute behavioral changes, seemingly associated with changes in diet, practitioners should consider testing the child for allergies and food intolerances,” they suggest. Given the possible risks associated with a strict GF/CF diet in developing children, including nutritional deficiencies and poor bone development, the researchers suggest limiting the use of GF/CF diets to autistic patients who have tested positive for a food allergy or intolerance to gluten or casein. Parents considering a GF/CF diet for their children should consult with a registered dietitian to help design a diet plan and supplement regimen that will meet their child’s growth and developmental needs.