Children with autism have gastrointestinal problems, and special diets can help resolve these issues.
That idea is all but accepted as fact by parents, advocates and scientists alike. Many parents of children with autism report that the children have frequent stomachaches, constipation or acid reflux, and some attribute these to problems digesting gluten or dairy proteins.
In a review published Monday in Pediatrics, a large and diverse group of pediatric experts states unequivocally that there is no evidence to support the idea of autism-specific gut problems or of a so-called ‘leaky gut’ that doesn’t allow children with the disorder to properly digest nutrients.
The journal periodically publishes these consensus reports to try to address controversial issues in an objective way, and to help guide physicians in making good diagnoses and treatment plans. For this one, the panel included 28 clinicians with expertise in, among other things, child psychiatry, epidemiology, allergies, nutrition and pain.
The group’s ultimate recommendation is to treat gut problems in children with autism as you would treat them in any child. The only difference between the two groups may be in how the child responds: a stomachache may make a typical child a bit cranky, but provoke more severe outbursts in a child with autism.
The panel doesn’t rule out the possibility that future research might uncover autism-specific gut problems, pointing out that studies to date are somewhat difficult to interpret. For instance, one study estimates that more than 70 percent of children with autism have gastrointestinal troubles, whereas another pegs that number at a paltry 9 percent.
The panel recommends that studies focus on more precisely calculating this prevalence, rather than on investigating gut issues as root causes of the disorder rigorously designed studies to more precisely calculate this prevalence and to investigate gut issues as root causes of the disorder.
In the meantime, the experts say it’s best to avoid the special diets pushed by the alternative medicine community. They have shown no benefit to children with autism, they note, and, if taken to extremes, could result in harmful malnutrition.
(Edited 1/9, thanks to comment from MJ)
5 comments
Comments feed for this article
January 8, 2010 at 7:15 pm
MJ
I think you may be misinterpreting the report a little. The report doesn’t say that there is unequivocally no evidence of an association, rather what it says (at least to me) is that the limited evidence available is inconclusive.
The report does say that the current evidence suggests that GI disorders are more common in children with autism than typical children. It also points out that nutritional problems are seen in children with autism regardless of whether the child is on any special diet.
Also, the report calls for more research into several areas involving GI issues and autism, not just prevalence.
January 9, 2010 at 3:24 pm
virginiahughes
Hi MJ,
Thanks for commenting. After re-reading the study, I see that you’re right about the panel recommending many kinds of rigorous research studies, including those on root causes, so I adjusted the post text a bit to reflect that.
I don’t agree with your other comments, however. I think that the panel is saying (as directly and unequivocally as possible for a group of that size) that the evidence so far has not shown any convincing evidence for autism-specific GI issues. They state this idea over and over. They also say (as I did here) that, of course, much more research is necessary to sort out lingering questions. But that’s the case with all science — you have to make informed decisions based on the real evidence you have now, not on what might possibly be shown in future studies.
I took a look at your blog, and see that two of your girls are benefiting from special diets. That’s wonderful, and I don’t dispute that dietary adjustments could be a good thing for some kids. (And adults — I made some serious dietary adjustments myself about seven years ago, and it definitely improved my sleeping patterns and my mood.) But lots of non-autistic kids have dietary problems, too. So far, no solid science supports a causal link between GI problems and autism.
January 10, 2010 at 2:33 pm
MJ
I think what they are saying is more nuanced that simply saying that there is no evidence.
You are correct that they say that Wakefield’s “autistic enterocolitis” or another disorder that is specific only to autism has not been established. But that isn’t too surprising, this question has not been researched – mostly due to the stigma attached to the issue by Wakefield.
The paper goes onto talk about abnormal intestinal permeability (“leaky gut”) playing a role in “neuropsychiatric manifestations of ASDs” and there they say there is limited evidence but the available research has not confirmed that this is happening or even if it is whether it contributes to autism. The paper calls for more research in this area.
Finally, the paper looks that the prevalence of GI abnormalities in people with autism and concludes even with limited information that -
“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”
I think these are three separate statements, the strongest one being that GI disorders appear to be more common in people with autism. Now you are right in saying that the paper does say that there is not evidence of a autism specific GI disorder. But the simple fact that GI disorders appear to be more common in people with autism means that it is likely that there is some sort of relationship – either autism can cause GI issues, GI issues contribute to autism, both are related to some other factor, or a combination of all three.
On a related note, I find it interesting that my twin girls need the diet but my youngest daughter does not. The twins both have had nutritional deficiencies before we started a special diet (zinc, iron) and still have them after the diet (iron, cholesterol, protein) – even though we have taken steps to ensure that they get enough of these in their diets. My youngest does not show these nutritional deficiencies. The interesting thing for me is the twin’s autism is more severe than the youngest – especially in the area of restricted or repetitive behaviors.
January 10, 2010 at 2:47 pm
virginiahughes
MJ-
RE: “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”
Yes, they wrote that. Right before it, they also wrote:
“Most of these studies had 1 or more methodologic limitations, in particular a lack of appropriate (nonrelated) control groups”
…and right after it, they wrote:
“prospective multicenter studies need to be performed by using validated instruments and outcome measures administered to persons with a diagnosis of ASD established by accepted methods and appropriate control groups. Population-based studies are also needed to avoid referral bias and overestimation of the prevalence of gastrointestinal symptoms in patients with ASDs.”
This panel is bending over backwards to be conservative and accurate in their report. Taking all of the statements as a whole, however, I think this is a reasonable interpretation of their message:
So far, there have been a lot of poorly designed studies — many, even, without control groups — that claim a high prevalence of GI disorders in autism. This is not adequate evidence. We need much more rigorous studies to draw any conclusions.
January 11, 2010 at 10:19 am
RAJ
MJ’s website discusses genetic syndromes associated with ASD as follows:
ASDs tend to occur more often in people who have certain other medical conditions. About 10% of children with an ASD have an identifiable genetic, neurologic, or metabolic disorder, such as:
Fragile X syndrome
Tuberous sclerosis
Down syndrome
Other chromosomal disorders
A new study shows that the association between genetic syndromes and ASD are superficial:
http://www3.interscience.wiley.com/cgi-bin/fulltext/122577050/HTMLSTART
If the genetic syndromes are removed the only studies associating ASD with gene transmission are the twin studies. Classical twin studies do not seperate concordance rates by placentation status and therefore cannot distuingish genetic transmission from genetic susceptability.
Leprosy is caused by infection after exposure to myobacterim laprae. Twin studies in leprosy have reported the same high concordance rates ( 60 -85%) in identical twins and the same rapid falloff in fraternal twins ( 5 -20%) that has been reported in ASD twin studies.
http://www.ncbi.nlm.nih.gov/pubmed/11279529?