Autism and the Gluten-Free, Casein-Free (GFCF) Diet

Jennifer H. Elder, PhD, RN, FAAN

Professor and Associate Dean of Research

University of Florida

Parents of children with autism spectrum disorder (ASD) are faced with difficult treatment decisions that are complicated by the vast information on the web. One of the most popular interventions continues to be the gluten-free, casein-free (GFCF) diet despite the fact that limited scientific evidence supports its use. This article will apprise  families about current research regarding the GFCF diet, and help them determine whether it is best suited to their child and family lifestyle.

The Gluten-Free, Casein-Free (GFCF) Diet

 The most popular rationale for this diet is the “opioid-excess theory”, which states that excess opioid-peptides, caused by the incomplete breakdown of foods with gluten and casein, trigger autistic symptoms (Panksepp, 1979; Reichelt, Ekrem, & Scott, 1990; Shattock, Kennedy, Rowell, & Berney, 1980). Another popular theory is that children with autism have “leaky gut syndrome”, which involves opioid-peptides crossing the intestinal and blood-brain barriers, and ultimately affecting the endogenous opiate and central nervous systems. Some assert this “leaky gut” may help explain why many children with ASD have gastrointestinal (GI) symptoms such as diarrhea and constipation in addition to social and communication deficits (Horvath & Perman, 2002a).

While these theories are interesting, they have not been well-studied.  The largest trial was conducted by Whiteley et al. (2010) with 72 subjects, and results were positive; indeed, children demonstrated improvements in the following: language, attention, concentration, interaction, communication, hyperactivity, motor coordination, repetitive behavior patterns, social integration, and self-injurious behavior/altered pain perception. There have been four other published randomized, controlled clinical trials of the GFCF diet, but they have been limited by small sample sizes, high dropout rates, and diet noncompliance (Elder et al., 2006; Hyman et al., 2010; Johnson, Handen, Zimmer, Sacco, & Turner, 2011; Knivsberg, Reichelt, Hoien, & Nodland, 2002). In addition, studies may be affected by the parent placebo effect, which occurs when parents are aware that their child is on the diet and report positive results that may not actually exist (Elder et al., 2006; Knivsberg et al., 2002). Finally, because ASD affects children differently, it is difficult to determine which children are likely to respond to the GFCF diet as well as its effects on symptoms.

Pros and Cons of the GFCF Diet

In evaluating treatment options, families should avoid hasty decisions that may result in falling prey to unsubstantiated or even bogus claims. Until the GFCF diet is further researched, parents should consider the following before implementation:

1. While GFCF foods are more readily available, the diet can be costly, time-consuming, and more difficult in geographic areas that lack the appropriate ingredients.
2. At least one family member should accurately record food intake and review the effects of the GFCF diet on symptoms regularly with health care providers.
3. Families need plans about how to ensure dietary compliance at home and in different settings (i.e. school, home of friends or family). It is often helpful to identify another parent or professional who has implemented the diet and can offer practical advice for food preparation and compliance.
4. The child’s health should be evaluated by a professional prior to diet implementation.  If the child is eligible, then health and weight should be monitored to avoid compromising nutritional status.

References

Elder, J., 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. J. Autism Dev. Disord., 36(3), 413-420. doi: 10.1007/s10803-006-0079-0

Horvath, K., & Perman, J. A. (2002a). Autism and gastrointestinal symptoms. Current Gastroenterology Reports, 4(3), 251-258.

Hyman, S., Stewart, P., Smith, T., Foley, J., Cain, U., & Peck, R. (2010). The gluten free and casein free (GFCF) diet: A double blind, placebo controlled challenge study. Paper presented at the International Meeting for Autism Research, Philadelphia, PA.

Johnson, C., Handen, B., Zimmer, M., Sacco, K., & Turner, K. (2011). Effects of Gluten Free / Casein Free Diet in Young Children with Autism: A Pilot Study. Journal of Developmental and Physical Disabilities, 23(3), 213-225. doi: 10.1007/s10882-010-9217-x

Knivsberg, A. M., Reichelt, K. L., Hoien, T., & Nodland, M. (2002). A randomized, controlled study of dietary intervention in autistic syndromes. Nutritional Neuroscience, 5, 251-261.

Panksepp, J. (1979). A neurochemical theory of autism. Trends Neurosci., 2, 174-177.

Reichelt, K. L., Ekrem, J., & Scott, H. (1990). Gluten milk proteins and autism: Dietary intervention effect on behavior and peptide secretion. J. Appl. Nutr., 42, 1-11.

Shattock, P., Kennedy, A., Rowell, F., & Berney, T. (1980). Role of neuropeptides in autism and their relationships with classical neurotransmitters. Brain Dysfunction, 3, 315-327.

Whiteley, P., Haracopos, D., Knivsberg, A.-M., Reichelt, K. L., Parlar, S., Jacobsen, J., . . . Shattock, P. (2010). The ScanBrit randomised, controlled, single-blind study of a gluten-and casein-free dietary intervention for children with autism spectrum disorders. Nutritional neuroscience, 13(2), 87-100.