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Evaluating the GFCF Diet

Written by: Joshua Sleeper

Conclusive evidence used in reference to this blog is derived from scholarly journal article “The Gluten-Free, Casein-Free Diet and Autism: Limited Return on Family Investment,” taken from the ‘Journal of Early Intervention’ 2013 35:3, published online April 9, 2013. Reference available at the bottom of the post.

Team members at Trumpet Behavioral Health frequently receive questions about Gluten-Free Casein Free Diet (GFCF), as well as stories from families who have tried this approach. We’ve assembled this blog to provide a general overview of GFCF as a whole, as well as highlight some important points about the diet itself.

What is a GFCF Diet?

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Quite simply, a GFCF diet is one that eliminates dietary intake of the naturally occurring proteins gluten (found most often in wheat, barley, rye, and commercially available oats), and casein (found most often in milk and dairy products).

The first purported connections made between diet and mental illness came about in the 1960s from Dr. Francis Curtis Dohan, a research physician and endocrinologist.

Why is the diet so prominent?

GFCF diets are utilized by 50% of families of a child with ASD. There are a number of reasons for the popularity of the diet, including:

  • Accessibility: Parents can implement the diet in their own homes and do not need guidance or training from other professionals. Guidelines of the diets are fairly straightforward, and the availability of foods meeting GFCF requirements has increased dramatically in recent years.
  • Multi-treatment approach: The GFCF elimination diet can be implemented at the same time as other therapies or treatments are taking place. Many parents are constantly looking for ways that they can do more to potentially help their child be successful and the ability to layer this approach on top of additional therapies can be appealing.
  • Testimonials: Many families might be exposed to testimonials from parents of children with ASD that claim their child experienced a reduction in symptoms after implementing the GFCF elimination diet. It can be very powerful to hear from someone who has been through what you are currently experiencing and seems to have found a successful treatment.
  • Media: Similar to the power of testimonials, prevalence of the GFCF elimination diet in popular media or resources related to ASD can result in more families attempting it with their own children. Books, websites, and statements from celebrities promoting positive effects of the diet are readily available for parents, teachers, and caregivers to access when looking for information on possible treatments following an ASD diagnosis.

Child Eating Is there science backing an effectiveness of the GFCF diet?

Several theories exist which suggest that a reduction of behaviors related to ASD may have a connection with the GFCF diet. Two theories include the opioid-excess theory of autism and gastrointestinal (GI) difficulties.

  • The opioid-excess theory carries arguments that some children with ASD have been found to have high levels of opioid peptides in urine tests. These high levels of opioid peptides have been posed to be due gluten and casein malabsorbtion. Furthermore, it is believed by proponents of this theory that the peptides leak from the intestines, into the bloodstream and eventually reach the brain. Once the peptides reach the brain they are believed to attach themselves to neuroreceptors, negatively impacting neurotransmission. This theory was originally proposed by Panksepp (1979). The underlying argument of this theory is that by removing gluten and casein from the diet of individuals with Autism, the level of opioids produced by the body would be greatly reduced and therefore, behaviors would decrease.
  • The second theory discussed in the article has to do with behaviors evoked by GI difficulties. It is suggested that dietary intake of foods which contain substances which an individual with ASD may be allergic to can cause discomfort and bloating and therefore may result in behaviors. This concern is increased with individuals who have communication delays as they may not be able to express their discomfort effectively and resort to communicating through maladaptive behaviors.

The referenced article from ‘Journal of Early Intervention’ recommends that children be tested for food allergies/sensitivities and celiac disease in order to appropriately recommend a diet which may align with their specific needs.

What are the drawbacks to the diet?Young Girl Yummy Cake

As with any proposed treatment, a cost-benefit analysis is important to consider. In addition to reviewing the literature to determine any empirically based benefits to implementing this elimination diet, the Journal of Early Intervention article outlines a few potential drawbacks to doing so as well. These include:

  • Advanced planning/additional effort: Preparing special meals each day without ingredients found in many common food items can be tedious. Any special events such as holidays, vacations, or even just going out to eat at a restaurant can require advanced food prep to ensure there will be food available that fits within the specified restrictions.
  • Increased expenses: Often times, food that is compatible with this diet can cost much more than similar items which contain gluten or casein.
  • Nutritional balance: As you eliminate foods that are often staples for developing children, you may rely heavily on a restricted group of foods and risk decreased nutritional value and a healthful, balanced diet. This could potentially lead to decreased bone density, or additional health issues.
  • Social consequences: Children with special diets that differ from their peers will often have to opt out of special treats or snacks that may be widely prevalent in many educational settings. This can be frustrating for the child when they are not allowed to eat the cupcake or crackers that their peers are given, and could also potentially be socially stigmatizing when others notice that they are always having to have something different or special.

Final conclusion

Results of the article concluded that through the investigation of five well-controlled studies, the positive effects on behavior for individuals with Autism by implementing a GFCF diet were inconclusive. The research conducted for this article did not support the opioid-excess theory. It is recommended that families and caregivers of individuals with ASD prioritize evidence-based interventions when deciding what approaches to take. The GFCF diet has not been shown to have sufficient scientific or empirical support for the reduction of behaviors with individuals with Autism. However, it is recommended that children to be tested for celiac disease or food allergies and sensitivities as diet change may help individuals who test positive for such concerns.


 The Gluten-Free, Casein-Free Diet and Autism: Limited Return on Family Investment

Sarah Hurwitz

Journal of Early Intervention 2013 35:3 originally published online 9 April 2013

DOI: 10.1177/1053815113484807