Monday, the Mayo Clinic published one of the first comprehensive examinations of autistic dietary patterns in the journal Pediatrics, finding that autistic children suffer from some but not all digestive maladies more than did their non-autistic counterparts over the study’s 18 year examination. Pediatrics also published an equally compelling finding about the autoimmune disorder Celiac’s disease (gluten allergy) and autism, confirming for the first time there is a strong correlation between the two often bewitching conditions. Both studies underscore the nature/nurture debate surrounding the still obscure causes of autism; is it merely a genetic disorder or a genetic predisposition pushed by environmental toxins? And what can dietary interventions, like the oft prescribed gluten-free casein-free diet, do for autistic children?
The Faces of Autism, from flickr user alainelorza
Autism + Stomachaches = More Theories, Questions
The Mayo Clinic study focused on ‘gastrointestinal’ disorders, a sometimes confusing umbrella term which obscures the results of this study. To clarify, scientists parsed out what lay folks might plainly call ‘stomachaches’ into five different categories:
- (1)constipation
- (2)diarrhea
- (3)abdominal bloating, discomfort, or irritability
- (4)gastroesophageal reflux or vomiting
- (5)feeding issues or food selectivity
Of the five categories, only (1) constipation and (5) food selectivity were heightened among the autistic children – leading the authors to conclude that there was no difference in the ‘overall cumulative incidence‘ of these disorders between the healthy and autistic children. Their study was especially important because it was the first that used a control group of healthy kids and it spanned almost 20 years.
However, findings that two of the five conditions were worse among autistic children may seem very significant if you are the parent of an autistic child. The authors do offer some conjecture as to why constipation and food selectivity tested differently in their experiment. Their theory: odd dietary demands from the autistic and the psychotropic drugs the autistic often take. From the study, on constipation (emphasis mine -ed):
The ritualistic tendencies, need for routine, and insistence on sameness that are characteristic of children with autism may lead these children to choose and demand stereotyped diets that may result in an inadequate intake of fiber, fluids, and other food constituents. Thus, behaviorally related food selectivity may, in turn, lead to constipation.
And on the drugs (again, emphasis mine -ed):
In a previous study, we reported that 52.4% of the children with autism in this population were treated with stimulant medications to control symptoms of hyperactivity, impulsivity, and inattention. Because appetite suppression is a known adverse effect of these medications, this may represent another factor that contributes to changes in eating patterns experienced by children with autism. In addition, many children with autism are treated with risperidone, and this may result in increased appetite and weight gain.
More Faces of Autism, from Flickr user alainelorza
More Faces of Autism, from Flickr user alainelorza
Autism + Autoimmune Diseases = Strong Correlation, For Some
The second study from Pediatrics is even more interesting. It examined the entire country of Denmark, trying to see if a family history of autoimmune disorders (that is disorders where the immune system attacks the body instead of defending it) helped predict which children would develop autism. Past studies have indicated a significant correlation between autoimmune conditions like psoriasis [1], rheumatoid arthritis and type 1 diabetes [2], but additional study was required. Enter the latest autoimmune – autism research from today.
Researchers confirmed the strong links between the genes associated with rheumatoid arthritis and type 1 diabetes and added to the mix an association with celiac’s disease. Anyone familiar with the latest dietary craze of gluten free foods will recognize celiac’s disease as the most severe form of gluten intolerance, where sufferers must abstain completely from all wheat products. The correlation has to do with the genes that create the environment for autoimmune disorders, which can give us some insight into why there has been so much anecdotal evidence that a gluten-free diet gives some relief to autistic children. Exactly how this new science applies take a bit more explaining though.
Questions Raised, Answered
We can see autistic children do have more digestive problems and inherent significant genetic disadvantages from their parents. Now, this does not mean ‘autism is caused by wheat’ or something that simple. Instead, these new studies are proving a much broader point: that both autism spectrum disorders and autoimmune disorders have a strong, possibly similar genetic component that can be triggered by a wide array of environmental toxins, one of which may be diet related. These findings, when abstracted, can apply towards to the now popular gluten-free casein-free (GFCF) diets many autistic parents enthusiastically talk about.
The Official Awareness Ribbon for Autism
While Mayo Clinic’s findings were publicly presented in the New York Times as a disassociation, a closer look at the study showed many autistic children do have issues with diet – and it is backed by science. We also know these children have delicate genetic predispositions that lend themselves to exploitation by environmental toxins – in much the same way adults develop autoimmune disorders. Combine those facts with some of the more aggressive theories in autism research and it gives a factual base to the GFCF diet claims.
The GFCF – Opiate Connection
GFCF diets theoretically aid autistic children by helping them to avoid opiates. Yes, opiates – similar to the ones found in opium and heroin, just much lower concentrations. Scientific investigation has found the incomplete metabolism of the proteins gluten and casein result in opiate peptides circulating in the bloodstream, eventually crossing the blood-brain barrier [3] [4]. This idea was the genesis of the GFCF diet: remove the opiate triggers of wheat and dairy, you could theoretically relieve some autistic characteristics [5].
This same logic may help explain findings where we have seen celiac disease and other neurological disorders, like schizophrenia, strongly associated with each other [6]. Both are mostly genetic diseases that get pushed by environmental circumstances – and the second study in Pediatrics shows autism specifically shares a genetic heritage with these particular autoimmune disorders. The opiate theory has been directly tested in the form of GFCF diet trials on a small scale with mixed results in the past, with most studies being small and seeking additional large scale research before issuing opinions in either direction [7] [8] [9].
More Faces of Autism, from Flickr user alainelorza
New Findings, Familiar Questions
If we examine what we know from these new studies, it clearly establishes autism as having a strong genetic component shared with particular autoimmune disorders – specifically rheumatoid arthritis, type 1 diabetes and potentially now celiac disease. We also know that autistic children have difficult and imprecise food tolerances, from the Mayo Clinic study. The idea that opiates could be THE autistic trigger seems distant but that does not mean GFCF diets don’t help. The authoritative Cochrane Database review of GFCF diets shows in the few studies that have been done, there was marked improvement in ‘autistic traits, social isolation and the overall ability to communicate’. Those are major factors that improve the day to day life of any family dealing with autism. Larger studies need to confirm these findings but anecdotal information suggests many autistic families gladly adhere to the diet and see results from it.
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Jul 30, 2009 | By: John Serrao
Featured, Food, Health & Disease