The gluten-free casein-free diet in autism revisited

by Benison O'Reilly on Wednesday, June 23rd, 2010

In the Australian Autism Handbook, published a couple of years ago now, we discuss the gluten-free casein-free (GFCF) diet and the evidence for its use in ASDs.

We include mention of an ongoing— at that time—double-blind randomised controlled trial (RCT):

Currently the US National Institute of Mental Health (NIMH) is supporting a double-blind RCT to study the effectiveness and safety of GFCF diet. Thirty children following a GFCF diet will either be challenged with snacks which contain gluten and casein or receive identical placebo snacks. All children in the study will be receiving intensive behavioural intervention so that the effects of their early intervention program cannot influence the results. Researchers will try to identify the characteristics of children who are responders and the nature of that response. You can read about this trial at: http://clinicaltrials-nccs.nlm.nih.gov

Well, the preliminary results of that trial are now in and were presented at the recent International Meeting for Autism Research (IMFAR), held last month in Philadelphia. Unfortunately we only have an abstract to go on, and should probably reserve complete judgement until the full published paper is available for review, but this is a summary of  the research:

Children aged 30-54 months, receiving at least 10 hours/week of early intensive behavioural intervention (EIBI) were recruited. They were screened for milk/wheat allergies, coeliac disease, and anaemia prior to starting treatment.

After a strict GFCF diet for at least 4 weeks, they received weekly randomised, double-blind challenges (snacks) containing either 20 g wheat flour, 20 g evaporated milk, both, or neither on three separate occasions over 12 weeks . The snacks appeared identical and were similar in taste and texture.  Behavioural and other data was collected at baseline and at regular intervals throughout the 30-week trial; as well as prior to, and two and 24 hours after, the snack challenges.

In the end twenty one children were recruited. Of these, seven were eventually excluded from the analysis for medical or other reasons, leaving only 14 participants (12 male), with an average age of just over three and half years.

The researchers found no statistical change in frequency or quality of stools, sleep, activity measured by actigraphy*, or parent/teacher/observer scores of attention or activity when children’s baseline (before diet) measures were compared with treatment (during diet) measures. Nor did they detect any changes pre/post the gluten and/or casein challenges. In fact, one group measure of behaviour** actually improved 2 hours-post gluten &/or casein challenge, although in light of the small patient numbers this might be a chance finding.

The authors concluded:

This is the first study to examine the behavioral effects of a nutritionally monitored GFCF diet on attention, sleep, stool pattern, and core symptoms of ASD. While no favorable effects of the GFCF diet on attention, sleep and stool patterns were identified in group analyses, such effects may occur for individuals or for subgroups of children   (e.g. with significant GI disease), providing the basis for positive anecdotal reports.  Future studies need to address the potential effects of nutrition on behavior in children with ASD and be powered to evaluate subtle changes in core symptoms.

The abstract is available below:

http://imfar.confex.com/imfar/2010/webprogram/Paper6183.html

This is the second double-blind study to find no effect for the GFCF diet in young children with ASD. It may be, as the authors say, that there is a subgroup of children—possibly those with significant gastrointestinal symptoms—who do benefit dramatically from the diet, and more trials with greater patient numbers are clearly needed.  Nonetheless this adds to the body of evidence that not all kids on the autism spectrum will respond to the GFCF diet.

Those who are interested might also want to check out the latest Cochrane Review of the GFCF diet, updated in 2009 but prior to presentation of this latest study:

www.mrw.interscience.wiley.com/cochrane/clsysrev/articles/CD003498/frame.html

*According to Wikepedia, actigraphy is a relatively non-invasive method of monitoring human rest/activity cycles, commonly using a wrist-watch-like package. The unit continually records movements, which are later analysed by computer.

** The Ritvo Freeman Real Life Rating Scales (RFRLRS). This scale was developed to assess effects of treatment on 47 recognised behaviours of patients with autism. It is applicable in natural settings & can be used by nonprofessional raters.

13 COMMENTS

Gastrointestinal disorders and autism

by Benison O'Reilly on Wednesday, February 3rd, 2010

Parental anecdotes suggest that gastrointestinal disorders such as abdominal pain, constipation and chronic diarrhoea are more common amongst children with ASDs than in their typical peers. But are they really more common, or do parents of children with autism just look more strenuously for physical complaints that might explain their child’s odd and unsettling behaviours? Or maybe GI problems are more common in a subset of individuals with an ASD and the majority of kids on the spectrum remain unaffected?

The jury is still out. The reported prevalence of gastrointestinal symptoms in children with ASDs has ranged from 9% to 70% depending on the type of study used to assess this.(1) As it seems with most health issues associated with autism, the research surrounding this topic is patchy and often of fairly low quality, leaving lots of questions unanswered.

At last the mainstream medical community has tackled this evidence gap and produced a report with the ponderous title: Evaluation, Diagnosis, and Treatment of Gastrointestinal Disorders in Individuals with ASDs: A Consensus Report. Consensus reports are just that: a group of experts get together and reach a consensus, based on their own clinical experience and the existing evidence. In this particular case the experts came from a wide variety of disciplines: child psychiatry, developmental paediatrics, epidemiology, medical genetics, immunology, nursing, paediatric allergy, paediatric gastroenterology, paediatric pain, paediatric neurology, paediatric nutrition, and psychology.

The report is not without controversy, as it questions some accepted beliefs, or rather beliefs accepted by many parents and ‘biomedical’ practitioners working outside the mainstream. For example

• The existence of a gastrointestinal disturbance specific to persons with ASDs (eg, “autistic enterocolitis”) has not been established.

• The evidence for abnormal gastrointestinal permeability [in other words ‘leaky gut’] in individuals with ASDs is limited. Prospective studies should be performed to determine the role of abnormal permeability in neuropsychiatric manifestations of ASD

• Available research data do not support the use of a casein-free diet, a gluten-free diet, or combined gluten-free, casein-free (GFCF) diet as a primary treatment for individuals with ASDs.(1 )

Science-speak, sorry. Scientific writing is almost always like that; everything is qualified. It’s the nature of science—nothing is considered ‘proven’ until there is an overwhelming body of good quality evidence to support it—but unfortunately this sort of language sounds wishy-washy to parents desperately seeking answers.

Anyway, there are some significant breakthroughs contained in this report; in particular  it recognises that in individuals with an ASD and limited communication skills, gastrointestinal complaints (e.g. abdominal pain) may manifest themselves as problem behaviours like sleep disturbance, aggression and self-injury, and that physical causes for problem behaviours should be considered if a child with autism starts to act up unexpectedly. When it comes to investigating GI complaints we need to be particular vigilant with individuals who lack the ability to communicate their distress.

The report also calls for lots more research and recommends that all clinical studies include a genetic testing component, in the hope of identifying particular genotypes of children with ASD who are more prone to GI complaints.

For those who are interested, the report was published in the January issue of the medical journal Pediatrics and is free to download at: http://pediatrics.aappublications.org/cgi/content/full/125/Supplement_1/S1

1. Buie T, Campbell DB, Fuchs GJ, et al. Evaluation, Diagnosis, and Treatment of Gastrointestinal Disorders in Individuals with ASDs: A Consensus Report. Pediatrics 2010;125:S1–S18

17 COMMENTS