ARI Publication 40 – 2013 Version
Gluten-Free, C.asein-Free Diet (and often com-free and soy-free)
Rationale: It is important to note that human digestive systems have not evolved on a diet
containing high amounts of wheat and dairy products. Humans are the only animal who drink milk
as adults, and the only ones to drink the milk of another animal. Cow’s milk is a perfect food for
baby cows, but not for humans or infants.
Over the last several hundred years, wheat has been bred to greatly increase its gluten content,
and a typical US diet contains far higher amounts of wheat than humans were eating 1000-10,000
years ago. Gluten (in wheat, rye, barley, and possibly oats) and cow’s milk proteins (including
casein, ~ lactoglobulin, a-lactoalbumin which are present in all dairy products, including milk,
yogurt, cheese, ice cream, caseinate) can cause several problems:
- They are common food allergens (see previous section), causing both immediate- and delayedtype food reactions.
Many individuals with autism have low levels of lactase, the enzyme needed to digest lactose
(the sugar in milk). This results in bacteria consuming the lactose, resulting in painful gas,
bloating, and diarrhea.
- Certain peptides from gluten and casein can bind to opioid-receptors in the brain, and can have
a potent effect on behavior (like heroin or morphine), causing problems including sleepiness,
giddiness, inattention/”zoning out,” and aggressive and self-abusive behavior. Like opioids,
they can be highly addictive, and a lack of them can cause severe behaviors. This problem
appears to be due to an inability to fully digest the gluten and casein peptides into single amino
acids, and due to inflammation of the gut, which allows the gluten and casein peptides to enter
the bloodstream and reach opioid receptors in the brain. However, the evidence for this “opioid
hypothesis” is limited.
- Consumption of dairy products can cause the immune system to create antibodies against a
similar protein in the body, the folate transport receptor, which carries folic acid into the brain.
Individuals with cerebral folate deficiency have benefitted from a dairy-free diet.
Explanation of Treatment:
- Total, 100% avoidance of all gluten products and all dairy products. Even small amounts, like a
bite of a cookie, can cause allergic problems if the individual has immediate-type IgE-mediated
food allergy. Symptoms caused by delayed-type food allergy may be more dependent on dose.
Many foods have trace contamination with gluten; e.g., French fries and raisins are dusted with
wheat powder to keep them from sticking, so it can be very difficult to avoid all foods and
contaminated foods. In recent studies, extensively heated proteins (milk and egg) can be better
tolerated in patients with immediate-type milk and egg allergy.
- Digestive enzymes may be helpful, especially if there is an accidental exposure, for delayed type
food allergy, although efficacy is not well proven. In case of immediate type food allergy,
digestive enzymes will not be effective.
- Children with autism may also benefit from removing corn and/or soy products. It is of note
that soy protein is highly immunogenic. In children with Food Protein Induced Enterocolitis
Syndrome (FPIES, a condition in which food proteins cause inflammation of the gut) the most
common causative food proteins are cow’s milk protein and soy protein.