Bumble Bee Learns to Fly ….. a blog

The Gluten-Free Cassein-Free Diet (GFCF)

Factual, Plausible or Myth?

“The gluten-free, casein-free (GFCF) diet is based on the “ophoid excess theory”.  This theory is based on the hypothesis that children with ASD have a “leaky gut,” which leads to the absorption of biologically active casein – and gluten-deprived peptides (casomorphines and gluteomorphines), which cross the intestinal brush-border and act as opiates in the brain.  The implied consequences includes the interference of neurotransmissions and, subsequently, autistic behaviors.”  (Wallace, 2009, p. 2)  The GFCF diet limits two proteins: gluten (found in wheat, barley, rye, and oats), and casein (found in dairy products such as milk, yogurt, cheese, and ice cream).  Since gluten and casein are also found in many processed foods, the diet is extremely restrictive. (Wallace, 2009, p. 2)  This diet is expensive to implement and would also require extensive food preparation.  Furthermore, because children with ASD tend to have food sensitivities, I am concerned that parents would be limiting an already restrictive diet?  Could this be detrimental to the health of the child?

Reference:

Wallace, L.S. (2009, March). What’s the Scoop on Autism Spectrum Disorders    and Nutrition? The Exceptional Parent, 39(2), 1-4.

My Hypotheses

I hypothesize that children on the GFCF diet will show little to no improvement in autistic symptoms.

I also hypothesize that children on the GFCF diet will not eat a nutritionally balanced diet.

Let’s examine the evidence…

Summary of Double Blind Clinical Trail

“The Gluten-Free, Casein-Free Diet In Autism: Results of A Preliminary Double Blind Clinical Trial”

This study was a randomized, double blind, repeated measures, cross-over design. The sample consisted of 15 children, ranging in age from 2-16 years, who had a medical diagnosis of autism.  Researchers wanted to know if a Gluten-Free Casein-Free diet (GFCF) would affect urinary peptide levels, and reduce autistic symptoms.  They also wanted to know if parents experienced the placebo affect when administering the GFCF diet to their children.  They used three different instruments to measure their results including the Childhood Autism Rating Scale (CARS), the Ecological Communication Orientation (ECO) Language Sampling Summary, and the Urinary Peptide Levels (UPL).  They concluded that there was no significant different between the experimental group and the control group in either improvement of autistic symptoms or in lowered urinary peptide levels.  Several parents did feel their child improved on the GFCF diet and choose to maintain it even after the study ended.  The study was limited by a small sample size.  Secondly, the study was preliminary and only lasted for twelve weeks, which may not be enough time for children to make noticeable improvements. It will be interesting to see their final study results.

Reference:

Elder, J.H., Shankar, M., Shuster, J., Theriaque, D., Burns, S., Sherrill, L.  (2006). The Gluten-Free, Casein-Free Diet In Autism: Results of a Preliminary Double Blind Clinical Trial. Journal of Autism and Developmental Disorders. 36, 413-420. Doi: 10.1007/s10803-006-0079-0

Summary of a single-blind controlled study

“Effects of a Dietary Intervention on Autistic Behavior”

This study was a single-blind, controlled, randomized study with a one year intervention period.  Twenty children were chosen as participants: ten were on a Gluten-Free Casein-Free diet (GFCF) and ten were placed on a placebo diet. They used three measurement instruments: the DIPAB (which has two parts and measures functional skills as well as autistic behaviors), the Leiter International Performance Scale (which measures cognitive abilities), and the gradient dilution high performance liquid chromatography (HPLC), which measures urine peptide levels.  They hypothesized that they would “…register a decrease of autistic traits in the diet group, but not in the control group.” (Knivsberg, Reichelt, Hoien, Hodland, 2003, p. 248)  They confirmed their hypothesis.  In fact, children on the diet made remarkable gains as measured by the DIPAB.  “In the diet group, resistance to community social interaction and strange behavior decreased significantly, whereas willingness and ability to communicate increased significantly.” (Knivsberg, et. al., 2003, p. 254)  Researchers pointed out a few limitations of their study.  They were unable to measure final urinary peptide levels because so many parents did not return urine samples.  Also, their sample size was small, and they were not able to track compliance with the diet closely.  Lastly, the children in the diet group had grown and matured, which could account for some changes.  However, this is unlikely since the same improvements were not shown in the control group.

Reference:

Knivsberg, A.M., Reichelt, K.L., Hoien, T., Nodland, M. (2003). Effects of a Dietary Intervention on Autistic Behavior. Focus on Autism and other Developmental Disabilities, 18 (4), 247-256.

Does Nutritional Intake Differ Between Children with Autism Spectrum Disorders and Children with Typical Development?

An Article Summary

Researchers in this study compared the diets of two groups of children using a 3-day diet record that was kept by parents.  They were able to recruit 77 participants for their study, 46 diagnosed with ASD and 31 with typical development. They hypothesized that the children diagnosed with ASD would eat fewer foods from the different food groups and would consume fewer nutritional nutrients. (Herndon, DiGuiseppi, Johnson, Leiferman, & Reynolds, 2009, p. 213)  However, after analyzing the children’s diets, they found this to be true only in one food group, the dairy group.  Children with ASD consumed less calcium, even if they were not on the GFCF diet.  Otherwise, their diets were comparable to the diets of the control group.  Both groups ate less fiber, calcium, Vitamin E and Vitamin D than is recommended.  Although researchers found that both groups of children were eating nutrient deficient diets, it is encouraging to see that the children with ASD ate better than one might expect.  The researchers pointed out that their study was limited by the small sample size and the use of food diaries.  They relied on parent report entirely, which is a common method, but could be less accurate.

Reference:

Herndon, A.C., DiGuiseppi, D., Johnson, S.L., Leiferman, J., Reynolds, A. (2009).  Does Nutritional Intake Differ Between Children with Autism Spectrum Disorders and Children with Typical Development?  Autism and Developmental Discord, 39, 212-222.  Doi: 10.1007/s10803-008-0606-2

Gluten and Casein Free Diets in Autism: A Study of the Effects on Food Choice and Nutrition.

Article Summary

Researchers gathered their data through a questionnaire that was sent to parents of children with ASD.  Eight of the families followed a GFCG diet, and 29 did not.  All of the children had ASD.  They did not find significant differences in the nutritional intake of the two groups.  Their study was also limited by the small sample size because they got a low response rate when they sent out their questionnaires.  Also, there is potential for bias when relying on parent’s reports, but a diet diary is much more accurate than historical recall of information.

Reference:

Cornish, E. (2002).  Gluten and Casein Free Diets in Autism: A Study of the Effects on Food Choice and Nutrition.  Journal of Human Nutrition Dietetic, 15, 261-269.

Treatment of Food Selectivity in a Young Child with Autism.

Article Summary

Researchers used a multiple probe research design across food categories.  Their participant was a 5.5 year old boy that was diagnosed with ASD and was on a GFCF diet.  They used four treatments: combined task direction, contingent reinforcement, physical prompts, and procedures to introduce food gradually.  They videotaped his responses at each feeding and carefully recorded them.  They noted an improvement in both the variety of food the child would consume and the amount.  This is hopeful news to parents who have difficulty feeding their children with autism a balanced and adequate diet due to food sensitivities.  Researchers pointed out that the study was limited by the use of four variables or treatments.  Although the improvements were remarkable, it is difficult to say which variable or variables were the most effective.  Also, the study was limited because they only tested one child.  It would be interesting to try the same treatments on a larger sample of children with food sensitivities.

Reference:

Wood, B.K., Wolery, M., Kaiser, A.P.  (2009). Treatment of Food Selectivity in a Young Child with Autism.  Focus on Autism and other Developmental Disabilities, 24 (3), 169-177.  Retrieved from: http://focus.sagepub.com

The most compelling evidence comes from the first two studies that I reviewed.  I am not surprised that they found little improvement in autistic symptoms, since the first was a preliminary study and was limited by a short test time and a small sample size.  However, the second study really surprised and intrigued me.  The improvements were too radical to ignore.  I was disappointed that the researchers were unable to test urine samples during their post tests.  I would have loved to see some medical evidence.  Still, the improvements in social communication for the children on the GFCF diet are too consistent to ignore.  So, based on these two research studies alone, I need to contradict my hypothesis and vote that the diet is a plausible medical theory.  I eagerly await further research.

The final three research studies examined the eating habits of children with autism.  I was also surprised by their results.  They found little difference between the diets of children with autism and those of children with typical development.  Also, children limited to the GFCF diet ate comparable amounts of nutritious foods as those who were not on the diet.  Based on these results, I will also have to change my second hypothesis.  Children on the GFCF diet do not eat a less balanced diet than children who are not.