The January 2010 issue of the journal Pediatrics includes two newly published studies investigating GI and dietary issues in children with Autism (1,2). The lead author for both studies was Dr. Timothy Buie. After reading the actual studies, I quickly realized how the media has put out material, which can lead the public to incorrect conclusions. For example, in response to the Buie studies, the Associated Press carried an article written by Carla K. Johnson, which started out with the following paragraph,
“An expert panel says there's no rigorous evidence that digestive problems are more common in children with autism compared with other children, or that special diets work, contrary to claims by celebrities and vaccine naysayers.” (3)
There are two parts to that paragraph and I will address each one separately. The first part concerns the prevalence of GI problems in children with autism. Some might interpret the lack of evidence as “proof” that children with autism do not have a higher incidence of GI problems. This situation extends back to an earlier study published in the same journal so I will pick up the story there.
The August 2009 issue of Pediatrics presented a population-based study, which looked at the incidence of GI symptoms in 121 case children with autism (4). According to this study by Ibrahim SH et al. they found a higher occurrence of constipation in children with autism however no difference was observed in the overall incidence of GI symptoms. Ibrahim’s study stated that because constipation has a
“behavioral etiology, data suggest that a neurobehavioral rather than a primary organic gastrointestinal etiology may account for the higher incidence of these gastrointestinal symptoms in children with autism.”(4) It further went on to explain that,
“Our findings are consistent with previous reports that have found that children with autism do not have an increased rate of either gastrointestinal disorders in general or celiac disease in particular.”(4)
Just to make sure the Pediatric readers “really” understood that there were no GI problems associated with autism, this same issue published a commentary by Gilger MA et al. in which Gilger reiterates the Ibrahim findings that,
“…the overall incidence of gastrointestinal symptoms did not differ between cases of autism and controls.” and that, “Ibrahim et al are to be commended for a well-performed study, with which they attempt to put to rest the nagging suggestion that there exists a link between autism and gastrointestinal disease.”(5)
Back in August, the media immediately jumped on this “well-performed” study to tell us that autism and GI symptoms are not related.
But is this what the Pediatrics articles by Buie found? Did Buie say that the prevalence of GI symptoms in autism is the same as in the control population? Absolutely NOT!
In the study, Buie tells us that,
“The prevalence of gastrointestinal abnormalities in individuals with ASDs is incompletely understood.”(1)
He furthermore goes on to say,
“Despite the limitations in type and quality of available evidence, the preponderance of data were consistent with the likelihood of a high prevalence of gastrointestinal symptoms and disorders associated with ASDs.”(1)
What can account for the major difference between the findings published in the August Pediatrics study by Ibrahim and the January Pediatrics study by Buie? The answer to that becomes evident when you read Buie’s two papers. Buie goes into extensive detail explaining how the diagnosis of autism may cause doctors to overlook GI symptoms because children with autism present in an atypical and nonverbal manner. This stands in contrast to the August study by Ibrahim who so easily dismisses the elevated occurrence of constipation in children with autism as being a “neurobehavioral” problem.
The second area of misunderstanding by the press concerns the use of the gluten-free (GF) diet that is currently being successful utilized by so many parents (including myself) who have children on the autism spectrum. For individuals diagnosed with celiac disease a GF diet is the only proven method of treatment. But do children with autism have celiac?
A 2009 celiac study by Ludvigsson JF et al. (6) found 28% of children with a form of celiac called latent celiac had constipation yet Ibrahim easily dismissed the constipation in children with autism as being behaviorally related. He specifically tells us that in his cases of 121 children with autism there were no diagnosed celiacs. He does not tell us if any of the 121 cases had actually ever been screened for celiac. This is disappointing when one recognizes that using our current standards of celiac screening 90% of celiac disease is being missed and that celiac can be completely asymptomatic (7). Ibrahim then references one study, which he uses to conclude there is no increased prevalence of celiac in the autism population. It is of importance to note that the study he relied on screened a mere 11 individuals with autism for celiac (8).
Latent celiac is found in family members who have first-degree relatives with celiac. So it is critical to know that in the exact same issue of Pediatrics in which Ibrahim refuted an association of celiac with autism, another study just pages away found for the first time an increased risk of ASDs with a maternal history of celiac disease (9). Since the incidence of celiac disease among members who have a first-degree relative with celiac is significantly higher than that of the general population and maternal celiac is a risk factor for ASD, it is highly probably that children with autism have a higher incidence of celiac disease but it is going undetected. Clearly, such children would benefit by a gluten free diet but what about children with autism who do not have celiac?
The Buie study cited only one reference in which the value of a gluten free diet had been investigated (10). This study was a randomized double-blind cross–over study which looked at the behavioral impacts of a gluten-free casein-free (GFCF) in children with autism. This should have been considered the “gold standard” in science however; it had some rather severe limitations, which deserve your attention. Firstly, only 13 children completed the study. Secondly, the time on each arm of the study was only six weeks and there was no washout time between the crossover arms. The results were reported as grouped data and not as per individuals, none-the-less the following was said,
“It is also interesting that even though grouped data were non-significant for each of the dependent variables, behavior and language improvement could be seen in individual children.”(10)
“Clearly this was a heterogeneous sample in reference to age, severity of autism, and cognitive abilities and thus it was difficult to draw meaningful conclusions about the group as a whole.”(10)
As if the above information was not bad enough, the real kicker came when the authors said the following:
“…even though most parents were conscientious regarding the dietary restrictions, there were several reports of children “sneaking food” from siblings or classmates.”
In other words, this study was useless because it did not even assure the condition of being gluten free.
While it is a correct statement to say that the GFCF diet has not been scientifically tested, it is an error to say that it has been found useless. Thousands of parents have seen first hand the benefits of the GFCF diet and several published papers have documented such case studies. It is of particular interest to read some of the comments from one such thoroughly documented case study from a culture that is not so reliant on wheat. In the case history documented by medical doctors in Taiwan the authors acknowledge that,
“…this treatment option is more feasible with patients in East Asia than in western countries due to the different dietary habits and food selection.” (11)
After demonstrating the growth changes and changes in behavior (scored and reported) this group of Taiwan doctors state:
“In the future, we will try to analyze underlying biochemical alterations in children successfully treated with such dietary restrictions in order to precisely define and predict the subgroups of ASD that responded positively to this therapy”
Meanwhile, their recommendations are:
In our experience, this adverse-effect-free therapeutic intervention is worth promotion in children with ASD.
And I agree!
January 6, 2000
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