Top Reasons to Implement a Gluten-Free, Casein-Free Diet

There are several reasons why you should consider implementing a gluten-free, casein-free (GFCF) diet for your child with autism. In this article, we will discuss some of the science that supports dietary intervention for autism.

1. The GFCF Diet is Safe and Effective

This is a great reason to implement a GFCF diet for your child with autism. After all, if you can do something at home that is safe and may help your child, it is always worth a try.

2. Probable Improvements in Skills and Health

Yes, it's true. By simply eliminating gluten and dairy from your child's diet, you will likely see improvements not only in their health but their ability to develop skills as well.

After implementing the diet, parents report improvements in the following areas:

Better cognition (described as the “fog lifting”)
Improvement in receptive language
Improvement in expressive language
Better sleep
Reduction in disruptive behaviors
Less hyperactivity
Better bowel movements
Reduction in ear infections and other illnesses
Pain tolerance normalizing
Eczema clearing

3. Gluten and Casein Cause a Functional Folate Deficiency

As you know, folate is critical for proper brain development. However, current research suggests that many children with autism have low amounts of folate in their brain, a condition known as Cerebral Folate Deficiency.

Folate is important because it supports the metabolism of purines and pyrimidines, which are the building blocks of RNA and DNA. They are needed to make energy properly.

Folate is utilized by the body for cognitive development.

Casein (the protein in dairy):

Studies show that dairy blocks folate receptors. This is extremely important information because recent studies show that the majority of kids with autism have folate receptor autoantibodies that block folate from entering the cerebral spinal fluid.
Because most kids with autism are already low in folate, dairy can make that problem worse.

Gluten (the protein in wheat):

Most processed wheat products (cereal, pasta, bread, cake and cookie mixes) have added folic acid. Folic acid is the synthetic, oxidized form of folate.
Furthermore, most kids with autism have genetic polymorphisms that make it difficult to utilize folic acid. If this is the case, folic acid floats around in the blood, unable to be used, and can actually block folate receptors.

4. Gluten Contains Zonulin Which Contributes to Leaky Gut

Another important reason for implementing a GFCF diet for autism: gluten is high in zonulin, which can cause intestinal permeability (also known as “leaky gut”).

Increased gut permeability contributes to heightened reactions to food components in the intestinal tract of children with autism. As a result, the child becomes sensitive to any food that they eat often.

The reactions can vary from child to child but often include difficulty concentrating, constipation and/or diarrhea, and widespread inflammation. A 2017 review suggests that leaky gut may also contribute to anxiety and depression.

Zonulin is a protein that modulates the permeability of the GI tract. The higher the zonulin, the greater chance of gut permeability (AKA leaky gut).
In 2012, the American Academy of Pediatrics began to acknowledge the problem of leaky gut in autism. “The protein zonulin is a component of intercellular tight junctions that is involved in regulating gut permeability. Small-intestinal exposure to bacteria and gluten are two of the more powerful triggers for zonulin-induced tight junction disassembly.”
This 2021 study found significantly higher levels of zonulin (and therefore increased intestinal permeability) in subjects with severe gastrointestinal and autism symptoms.
Interestingly, individuals with ASD on gluten and casein free diets have significantly lower intestinal permeability than those on unrestricted diets.

5. Gluten and Casein Bind to Opioid Receptors in the Brain

An opioid reaction to long chain peptides (gluten and casein) creates a high pain threshold and a foggy, disconnected feeling, similar to the feeling of being drunk. Many parents report that “the fog lifted” after starting a gluten and casein free diet and this may be the reason.

Gluten and casein are very long chain peptides (small versions of proteins) and are very similar in structure to natural opioid-binding peptides.
They are difficult to break down, especially if the child has insufficient digestive enzymes.
If the child’s digestive system is not properly breaking down gluten and casein, undigested peptides from these foods can access the bloodstream via a permeable gut lining (AKA Leaky Gut).
Once in the bloodstream, they travel to the brain where they attach to the brain’s opiate receptors.
This opiate reaction causes an addiction to the food, much like an opiate drug would.
This opioid-like reaction is also the reason many kids go through withdrawal symptoms when gluten and casein are removed from the diet.

Research:

This study found abnormally high intestinal permeability in nearly 40% of autistic patients and in 21% of their first-degree relatives compared to less than 5% of normal control subjects.
See this study that shows β-casomorphin-7, one of the most biologically active milk-derived peptides, (BCM7) is significantly higher (1.6x) in the blood of kids with autism.
This analysis explains how exomorphins (produced outside the body) pose as endomorphins (made inside the body) and, if they reach the brain, can have addictive effects. They can also cause the symptoms of autism and other disorders such as schizophrenia.
- “Foods that contain exorphins, such as wheat and dairy products, have indeed a reputation for being rewarding and people find it extremely hard to give them up.”
- The reason we refer to them as “comfort foods” is because of the dopamine release.

For more information, please read “Peptides’ Role in Autism with Emphasis on Exorphins”.

6. Food Allergies/Sensitivities Trigger Mast Cells Which Contribute to Leaky Gut

We mainly think of mast cells when referring to something we're allergic to, but they do a lot more. Mast cells in the body are connected to the immune response and they release histamine, interleukins, proteoglycans, and other enzymes.

Thus, even eating foods that we are sensitive to can stimulate mast cells and thereby can create a permeable gut lining. Moreover, continuing to eat these foods makes the problem worse. But, when we stop eating foods that we are sensitive to, it calms the mast cells.

When mast cells living in the connective tissue that line the GI tract are stimulated by a food sensitivity or food allergen, like wheat or dairy, they release the contents of their granules which has been shown to cause a permeable gut lining (AKA “Leaky gut”).
This is one reason prescription oral mast cell stabilizers can be helpful for some kids with autism.
Dairy and wheat are two of the top eight allergens. However, you don’t have to have a food allergy to have a mast cell reaction, which is why a regular allergy test cannot test for mast cell reactions. The best test is fully removing these foods from your diet, in addition to any other foods that you may be sensitive to, based on your physical and emotional reactions to the foods. An elimination diet is the best test.

7. Gluten and Casein Increase Glutamate

This can be troubling because elevated glutamate and low GABA in the brain contribute to high anxiety, perseverating on topics, restlessness, tics, migraines, and Complex Motor Stereotypies which looks like flapping or stimming.

Recent studies tie elevated glutamate is to Autism.
Glutamate (which is an excitatory neurotransmitter) and GABA (which is a calming neurotransmitter) need to balance. Studies show that in autism, glutamate needs to be decreased and GABA needs to be increased.
Gluten and casein contain about 25% glutamic acid. When these proteins are degraded, pasteurized, or processed, they become free glutamate, which is problematic because it creates inflammation.
Reducing glutamate can also help with seizure activity.
Learn more about Glutamate here.

8. Gluten and Casein Fuel Inflammation

When the gastrointestinal barrier function is disrupted (as is described in "leaky gut" above), there is an increased passage of dietary and microbial antigens interacting with cells of the immune system, which causes inflammation.

This article focuses on the many issues with gluten that can cause inflammation.
We can see that the role of diet has a huge impact on neuroinflammation in this article published in Frontiers in Immunology.
Pasteurized milk is acid-forming because it contains lactic acid. It makes the stomach produce more acid, which may increase symptoms of reflux (GERD). In order to reduce inflammation, you want to consume an alkaline (not acidic) diet.

9. Milk is Very High in Hormones

Another reason to implement a GFCF diet relates to hormones. These hormones are not always good for a growing child.

To begin with, dairy is naturally very high in anabolic hormones, which stimulate growth.
In addition to that, dairy farmers inject cows with a genetically engineered bovine growth hormone called rBGH to increase milk production.
Even cows raised on an organic diet are often milked while pregnant. As a result, they produce milk that is full of hormones.

Also, exposure to hormones in dairy products may lead to precocious puberty or even cause cancer cells to grow.

10. The Science Supports A Gluten And Casein Free Diet For Autism

Finally, the most important reason that parents should consider implementing the GFCF diet: there are hundreds of studies that provide proof that it's beneficial for people with autism. Below, you will find a few of our favorites.

A. Effect of Gluten Free Diet on Gastrointestinal and Behavioral Indices for Children with Autism Spectrum Disorders: A Randomized Clinical Trial.

This 2016 study suggested that a gluten-free diet may be effective in controlling gastrointestinal symptoms and ASD behaviors.
80 children of which 54% had GI abnormalities
- Half (40 children) put on a gluten-free diet
- Half (40 children) remained on a regular diet
- Length was 6 weeks
In the gluten-free group, the prevalence of gastrointestinal symptoms decreased significantly and the gluten-free diet resulted in a significant decrease in behavioral disorders as well.

B. Comprehensive Nutritional and Dietary Intervention for Autism Spectrum Disorder - A Randomized, Controlled 12-Month Trial.

This 2018 12-month trial explains how nutritional interventions (healthy gluten, casein, soy free diet) and supplements can improve the quality of life for people with autism.
Nonverbal IQ increased significantly in the treatment group. In addition, interpersonal skills, coping skills, and communication were also significantly improved.
“Parents reported that the vitamin/mineral supplements, essential fatty acids, and GFCFSF diet were the most beneficial.”
Over 12 months, the treatment group gained 18 months of development, verses 4 months in the non-treatment group.

C. A Modified Ketogenic Gluten-Free Diet with MCT Improves Behavior in Children with Autism Spectrum Disorder.

This 2018 study suggested that a modified gluten-free ketogenic diet with supplemental MCT is a potentially beneficial treatment option to improve the core features of autism.
This study tells us that, for some kids, we need to go further than just gluten and casein free to see excellent results. The carbohydrates in gluten-free foods may still be problematic.

D. Biological Explanation for Wheat Sensitivity Found.

This new research is very pertinent to our kids who may not have celiac disease but react to gluten nonetheless.
“People with non-celiac wheat sensitivity have a weakened intestinal barrier, which leads to a systemic immune response after ingesting wheat and related cereals, new research confirms.”
- This tells us that you can react to gluten without having celiac disease.

E. Ketogenic Diet Versus Gluten Free Casein Free Diet in Autistic Children: A Case-Control Study.

Patients (aged 3-8) were equally divided into 3 groups:
- Ketogenic diet as modified Atkins diet (MAD)
- Gluten-free, casein-free (GFCF) diet
- Balanced nutrition which served as a control group
Both diet groups showed significant improvement in ATEC and CARS scores in comparison to control group, yet ketogenic scored better results in cognition and sociability compared to GFCF diet group.
The reason this study was important is because it emphasized the idea that sometimes diet change is bigger than just removing gluten and casein. It is also about including nutrient dense, nourishing foods.

F. Dietary Considerations in Autism Spectrum Disorders: The Potential Role of Protein Digestion and Microbial Putrefaction in the Gut-Brain Axis (an analysis).

“Indeed, strict implementation of the diet has resulted in substantially greater improvement ASD behaviors, physiological symptoms, and social behaviors. In addition, there are likely other dietary proteins that are similarly difficult to digest that have not been considered and need to be minimized in cases of a fragile gut.”
Regarding conflicting studies:
- “Overall, dietary intervention studies in these children have not been able to address the multiple, integrated consequences of inappropriate proteins in the diets of individuals with ASD, including dietary protein digestion, gut-associated immune responses, and potential perturbations to the intestinal microbiota, much less provide the diagnostics to build tailored solutions.”

Conclusion

As shown above, there are lots of reasons why you should consider implementing a GFCF diet for autism. For this reason, TACA has lots of tips and information on how to start the diet:

All content in this article is for informational purposes only, including links to products and/or websites mentioned. To clarify, TACA does not receive any compensation or commission for providing them.

Furthermore, the information on this page is not a substitute for professional advice, diagnosis, or treatment. For this reason, always seek the advice of your physician, therapist, or other qualified health provider with any questions or concerns you may have.

The Autism Community in Action (TACA)