Gluten Free/Casein Free diet and autism studied…and no sign of a benefit

9 Sep

Perhaps one of the more common alternative medical approach to treating autism is the gluten free/casein free diet. And alternative means–not demonstrated to be beneficial and, very often, not even well founded on sound reasoning. And by common, it appears that about 17% of parents have opted for some form of special diet, so GF/CF in particular is likely less than that.

The GF/CF diet (as it is often known) was first proposed based on the “opiod excess” theory and the “leaky gut” theory. Neither theory has shown itself to be valid.

A previous review found that “Currently, there is insufficient evidence to support instituting a gluten-free diet as a treatment for autism.” The clinical trial just published appears to be based on a study presented at IMFAR a few years ago.

The study was fairly simple–they put children on a GF/CF diet. They then gave the children snacks. Some contained gluten and/or casein. Some did not. The parents didn’t know which snacks were which. The behavior of the children was recorded and correlated against the inclusion of gluten or casein. And no benefit was observed. Here’s the study:

The Gluten-Free/Casein-Free Diet: A Double-Blind Challenge Trial in Children with Autism.

and abstract:

To obtain information on the safety and efficacy of the gluten-free/casein-free (GFCF) diet, we placed 14 children with autism, age 3-5 years, on the diet for 4-6 weeks and then conducted a double-blind, placebo-controlled challenge study for 12 weeks while continuing the diet, with a 12-week follow-up. Dietary challenges were delivered via weekly snacks that contained gluten, casein, gluten and casein, or placebo. With nutritional counseling, the diet was safe and well-tolerated. However, dietary challenges did not have statistically significant effects on measures of physiologic functioning, behavior problems, or autism symptoms. Although these findings must be interpreted with caution because of the small sample size, the study does not provide evidence to support general use of the GFCF diet

The study group is small, so it is possible they missed some benefit. But if the parent survey often quoted were correct and 69% of children showed a benefit, this study should have picked that up.

There are, of course, people who are sensitive to various foods. People both autistic and not. So some fraction of the population will benefit from elimination diets. But the idea that many promote of elimination diets as the first thing to try, no matter what (and there are people who do), is flawed at best.

By Matt Carey

10 Responses to “Gluten Free/Casein Free diet and autism studied…and no sign of a benefit”

  1. Agnieszka Wroczynska September 9, 2015 at 13:19 #

    What you can’t read from the abstract is that children “who had known gastrointestinal disorders” were excluded from the study. And also those with seizure disorder while seizures had been previously associated with non-celiac gluten sensitivity. So it all might have resulted in exclusion of potential diet responders.

    This study enrolled kids aged 3-5 years old, while the other by Pedersen et al. (PMID: 24075141) suggested that those “aged between 7 and 9 years seemed to derive most benefit from dietary intervention”.

    That’s why I think the study “does not provide evidence to support (…) use of the GFCF diet” in 3-5 years old children with autism with no other medical co-morbidity – and nothing more. I found neither this study nor ARI survey being useful for a parent or a clinician.

    Also 2/22 kids from this study “tested positive for tTg [antibodies], requiring evaluation for celiac disease”. I don’t know if CD was confirmed in them, but if so – then it’s unusually high prevalence, And if not, I really would like to know what would be their response to GF diet. Unfortunately this has been left unanswered.

    • Sullivan (Matt Carey) September 9, 2015 at 17:57 #

      Actual disorders (in gastrointestinal disorders) are not common in the autistic population, so excluding kids with GI disorders wouldn’t have reduced the sample population dramatically. Add to this the fact that the GF/CF diet is promoted as a treatment for all autistics, not just those with GI disorders. Gastrointestinal disorders and nutritional conditions (such as allergies) are more common in the autistic population, but about 20% report this.

      Take out nutritional and the 20% will obviously be lower. And, yet, we are told that over 60% of autistics are supposed to respond to the GF/CF diet. So, obviously the recommendation isn’t only for those with GI disorders.

      Also, one wants to see if any benefit is due to an interaction with autism, not an improvement of a GI disorder.

      The pubmed link you give is to a Paul Shattock analysis. You can’t claim the above study is weak and then use that study as evidence without noting that it is extremely weak. Add to that the fact that Shattock has been trying to get the leaky gut and GF/CF idea to be accepted for 2 decades with no success. So he claims that only a narrow age band shows benefit? Wow, after decades of anecdotes claiming that the GHF/CF diet was huge for younger kids? I don’t remember anyone telling me to try the diet and saying, “but it may not really be a benefit until your kid is 8 years old”. Much to the contrary. I was constantly told that the clock is ticking and I have to try everything NOW.

      Here’s a line from the abstract to the Shattock study: “Further analysis based on the criteria for original study inclusion on the presence of the urine compound, trans-indolyl-3-acryloylglycine may also merit further investigation.” How about a recent study from a group that used intestinal fatty acid binding protein as a biomarker for alleged leaky gut? I’ll have that up shortly.

      “I don’t know if CD was confirmed in them, but if so – then it’s unusually high prevalence,”

      A recent study put the prevalence of inflammatory bowel disease in the autistic population at less than 1%. Again, very different than what people have claimed from anecdotes. Or what a certain unethical GI specialist claims. And, no, I’m not referencing Wakefield. I don’t consider him a GI specialist. Maybe 20 years ago he was.

      Here’s a discussion of the IBD prevalence in the autistic population:

      GI disease and autism, GF/CF diet and autism are both very much oversold ideas. Yep, autistics can have GI disease. Yep, some people, even autistics, can benefit from exclusion diets. And it is sad that a focus on how to treat GI disease in the autistic population was delayed because of the insistence that this was somehow linked to vaccines. Yet another example of the vaccine antagonistic groups–including some within the autism parent community–causing us harm.

      • Agnieszka Wroczynska September 9, 2015 at 22:37 #

        Thanks for reply.

        I thought it’s worth adding some information about this study which one can’t get from the abstract as the full text is not open-access.

        Actually, the authors did not state how many children were excluded because of medical issues, GI and others. 1 was excluded because of celiac (ok, that’s clear), 1 on liquid diet, 5 for other reasons and 2 of those included were not evaluated because of tTg antibodies. Finally 14 were studied. I am still left with a question if this could influence the results.

        “Also, one wants to see if any benefit is due to an interaction with autism, not an improvement of a GI disorder.”

        If an improvement of a GI disorder interacted with autism symptoms, then I would like to read about this. If not – I would be delighted to see it proven. This is what I consider useful until all is clear about autism biology and it’s relations to GI issues. This was not the aim of this study so I didn’t call it weak, but I think that parents and doctors need different kind of studies if we really want to look for benefit for children with autism.
        English is not my first language so I will quote dr Buie: “Especially for dietary interventions, identifying a subgroup with characteristic presentation may allow a better prediction of—and perhaps expectation of—response.”

        Obviously, ARI parent report is not scientific so I don’t bother with it.

        tTg antibodies positive in 2 children of 22 screened may be associated with celiac disease (CD), but it’s not related to inflammatory bowel disease. I agree with your comment on IBD and autism and personally think that A. Wakefield and B. Bettelheim are among people who did most harm to the health and future of my son… but it’s off topic. If it was celiac disease in those 2/22 then it seems like much more than average in the population and something to explore. It’s a pity that the paper does not clarify.

  2. Roger Kulp September 10, 2015 at 17:06 #

    As someone with folate receptor autoantibodies,I have personally experienced a direct connection to diet,especially dairy consumption,and autism severity and brain function.So I am a real believer in the gut/brain connection when it comes to some forms of autism.Or schizophrenia for that matter.

    The schizophrenia studies are important,because they might point to a link between c(o)eliac disease and brain function.So might a study like the one by Nga Lau and others about c(o)eliac and autism.

    Not sure of the point of excluding children with c(o)eliac,unless this is meant to be a study of “pure” autism.There are many different forms of autism.Some are effected by diet,some are not.Would CFD/FRAs have been an exclusionary diagnosis for this study?

    Then there are studies like this
    In this study we have confirmed previous reports [21, 38, 39] suggesting that the prevalence of CD is not increased among children affected by ASD. It is therefore conceivable that gluten could be responsible for causing immune-mediated gastrointestinal symptoms also in ASDs patients without CD, although the exact mechanisms through which this immune response is elicited are still unclear [40, 41]. In CD, the percentage of patients carrying the HLA-DQ2/DQ8 haplotype is approximately 97%, and this haplotype is required to develop this gluten-induced autoimmune enteropathy. In gluten-sensitive individuals these haplotypes are present in about 50% of patients with this condition [42]. In our study, 41% of enrolled ASD patients were HLA DQ2/DQ8 positive, a percentage similar to that found in the normal population. This also supports the hypothesis that a subgroup of ASDs children could be SIR-triggered by gluten. The observation that subjects affected by gluten sensitivity often experience behavioural symptoms [42] further supports this hypothesis.

    I think there is still much debate,and dueling studies,if you will,if Nonceliac Gluten Sensitivity is real or not.Let alone what role it might play in autism.

  3. Dave September 11, 2015 at 12:03 #

    We actually tried a gluten free diet and a casein free diet separately. When we reintroduced casein, we noticed no changes, but when we re-introduced gluten, we noticed changes the following day. Our son’s teachers, who were unaware of the re-introduction, also noticed significant changes, and wrote to us to ask if there was a problem at home.

    So we resumed the gluten free diet, even though the science seems to indicate no benefit.

    Among our friends, we have three other friends who tried the same diet. Two of them saw no changes at all, and the other reported the exact same result that we did: Every time gluten was re-introduced, the behavior changes the following day were severe enough to be alarming.

    I can’t attribute this to “leaky gut”, because none of the four children in our group have any real gastrointestinal issues. Our child had a mild IgG reaction, but not anything that a doctor would consider a real allergy. The other possibility is that the gluten is overwhelming the glutamate receptors in his brain. I don’t know enough about this theory to know if it is real or not.

    I do know from my own observation that my son seems to benefit from being gluten free, and seems to have severe behavior problems when it is reintroduced. We have confirmed this enough times that it is clearly not our imagination.

    I don’t recommend the diet for everyone, because it clearly does not apply to everyone. But if there are people out there who are unsure, then it is a relatively harmless intervention to experiment with.


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