SafeMinds Looks closely at Hyman study on Effectiveness of a Gluten Free Casein Free Diet in Autism
Children with Markers for Celiac Disease Eliminated from Study
Another recent study that received a tremendous amount of media attention this last month was conducted by Susan Hyman from the University of Rochester and presented at the recent International Meeting For Autism Research (IMFAR). The study cast doubt on the utility of the gluten free casein free (GF/CF) diet in autism. View abstract.
According to Dr. Hyman, this study was the first to evaluate the behavioral effects of the GF/CF diet on attention, sleep, stool pattern and core symptoms of ASD. The study was designed using randomized double blind placebo controlled challenges. Children 30 to 54 months of age participating in an early intensive behavioral intervention program were enrolled and started on a strict GF/CF diet for 4 weeks and then exposed to challenges of either wheat, milk, or both and monitored following the exposure. While no favorable effects of the GF/CF diet were observed the authors report that such effects may occur for subgroups of children (e,g those with GI disorders) which may provide the basis for favorable reports from parents whose children are on the diet.
In looking more closely at the study twenty one children were initially recruited to participate in the study. Two were excluded for positive test results for anti-tissue transglutaminase (TTG), a marker for celiac disease and one for anemia, which is also a symptom of celiac disease. These three children were then excluded from the study and four additional children were not able to complete the study reducing the study size down to 14 total participants. Celiac disease (CD) is an immune-mediated enteropathic condition triggered in genetically susceptible individuals by the ingestion of gluten. The treatment of celiac disease is the strict elimination of gluten from the diet. Read more.
Celiac disease is thought to be rare in the United States where there are no large epidemiologic studies of its prevalence. In screening of those in at-risk groups the prevalence of celiac disease was reported as 1 in 22 in first degree relatives, 1:39 in second-degree relatives, and 1:56 in symptomatic patients. The overall prevalence of CD in not-at-risk groups was 1:133. Therefore, positive screening for celiac disease in 2 of twenty one children with autism considered to not be at risk is highly significant. Such highly significant finding of 10% of children with autism screening positive for TTG deserves further investigation. Pediatricians and clinicians who provide health care to children with autism should consider routine screening for celiac disease as part of their initial assessment. Hopefully the publication of this study by Dr. Hyman will include such recommendations.
SafeMinds Board member Katie Wright, who is a contributing editor for "Age of Autism," and attended IMFAR, wrote an article this week regarding the study. The article, titled "One Part Autism, One Part Denial: A Recipe for Scientific Stagnation" covers deficiencies in the study in greater detail.
