Celiac Disease, Gluten Sensitivity, and Autism: Is There a Connection?

Use of the gluten-free diet in autism is controversial (most medical studies don't report any benefit). But some parents maintain that the diet (mainly a variant of it that also eliminates milk products) has helped their autistic children. Could the diet work because those children actually have celiac disease, with celiac causing their symptoms of autism?

In the vast majority of cases, that's unfortunately not the case, and going gluten-free won't help your child's autism. However, recent research indicates there could be some links—possibly between mothers with celiac disease (which causes digestive and other symptoms) and their children with autism (a potentially devastating developmental disorder). In addition, it's also possible that non-celiac gluten sensitivity—a condition that's not yet well understood—might play some role in autism.

All this research on links between celiac disease, non-celiac gluten sensitivity, and autism is preliminary, and it, unfortunately, doesn't offer much hope to parents searching for help right now. But eventually, it may provide some clues to potential autism treatments for some children, and even to ways to prevent autism from developing in the first place.

What Is Autism?

In 2020, the CDC reported that approximately one in 54 children in the United States is diagnosed with an autism spectrum disorder (ASD), according to 2016 data. Boys are four times more likely to be diagnosed with autism than girls. The symptoms of autism generally appear when a child is between ages two and three, although they may be apparent earlier.

As you might gather from the term "spectrum," autism spectrum disorder encompasses a wide range of symptoms and disabilities. Someone with mild autism might have trouble making eye contact and might appear to have little empathy, but they would be able to hold a job and maintain personal relationships. Meanwhile, someone with severe autism (also called "low-functioning autism") might not be able to speak or to live independently as an adult.

Medical researchers don't believe there's one single cause of autism. Instead, they believe a combination of genetic and environmental factors leads certain children to develop the condition. Autism spectrum disorder does run in families, indicating genetic links, but other factors—including having older parents and being born very premature—also increase the risk.

There's no cure for autism. Treatments that have been shown to reduce symptoms include behavioral therapy and medications. But one treatment frequently used by parents—the gluten-free, casein-free (GFCF) diet—is closely related to the gluten-free diet used to treat celiac disease. That leads to questions about how the two conditions might be related.

Celiac disease is an autoimmune disease in which consumption of foods containing the protein gluten (found in the grains wheat, barley, and rye) causes your immune system to attack your small intestine. The only current treatment for celiac is the gluten-free diet, which stops the immune system attack by eliminating its trigger, gluten.

Autism and the Gluten-Free, Casein-Free Diet

Parents have been using the gluten-free, casein-free diet as an autism treatment for at least two decades (casein is a protein found in milk that has some similarities to gluten). The controversial theory behind the treatment is that children with autism spectrum disorder have a "leaky gut" that allows fragments of large proteins to leak from their digestive tracts. Gluten and casein are proteins.

According to this theory, the proteins gluten and casein—when leaked from the digestive tract—have an effect somewhat like opioids on the child's developing brain.

In addition, many children on the autism spectrum (more than 80 percent in one study) have digestive symptoms such as diarrhea, constipation, abdominal pain, or reflux, which in parents' minds bolsters the case for some sort of dietary intervention.

However, the truth is there's little evidence to back up this treatment: A review of major studies on the GFCF diet in autism found minimal to no effect on autistic symptoms. Still, some parents maintain that the GFCF diet has helped their children (in some cases dramatically), and some alternative practitioners continue to recommend it. This has led some to speculate on a potential connection to celiac disease.

Celiac Disease in Children With Autism

Could some children with autism also have celiac disease, and could that explain the success a few parents report having with the gluten-free, casein-free diet? Studies have been mixed on this point, although there's at least one documented case of an autistic child recovering from autism after being diagnosed with celiac disease and beginning the gluten-free diet.

The autistic child who recovered after being diagnosed with celiac and going gluten-free was five years old at the time of his diagnosis. The healthcare providers in charge of his care wrote that nutritional deficiencies resulting from celiac disease's intestinal damage may have been responsible for his autistic symptoms.

However, there's not much additional evidence in the medical literature for cases of celiac disease masquerading as autism. The largest study to date, conducted in Sweden using that country's national health registry, found that people with autism spectrum disorder were not more likely to later receive a diagnosis of celiac disease (which requires an endoscopy to show damage to the small intestine).

However, the study also found that people with autism were three times more likely to have positive celiac blood tests—indicating an immune system response to gluten—but no damage to their small intestines (meaning they didn't have celiac disease).

The authors speculated that people with an immune system response to gluten but with negative tests for celiac disease may have non-celiac gluten sensitivity, a condition that isn't well-understood but which the researchers noted has been linked to psychiatric disorders such as schizophrenia.

In fact, another study, led by researchers at Columbia University, concluded that the immune systems of some children with autism seemed to be reacting to gluten, but not in the same way that the immune systems of people with celiac disease react to gluten. The researchers urged caution with the findings, saying that the results don't necessarily indicate sensitivity to gluten in those children, or that gluten was causing or contributing to autism. However, they said that future research may point to treatment strategies for people with autism and this apparent reaction to gluten.

Autism and Autoimmunity

Could there be some other link between autism and the gluten-related autoimmune condition celiac disease? Maybe. Medical studies indicate that there may be a connection between autoimmune conditions in general and autism, specifically between mothers with autoimmune conditions (including celiac disease) and autism in their children.

Research has shown that people with a family history of autoimmune conditions (remember, celiac disease is an autoimmune condition) are more likely to have a diagnosis of autism. One study found that mothers who had celiac disease had three times the normal risk of having a child with autism. It's not clear why this was so; the authors speculated that certain genes could be to blame, or possibly that the children were exposed to their mothers' antibodies during pregnancy.

Ultimately, if science could accurately identify a subset of women who were at risk of giving birth to an autistic child due to specific antibodies, researchers could explore ways to calm the immune system response during pregnancy and perhaps even prevent some cases of autism. However, we're far from such an outcome right now.

A Word From Verywell

Autism is a devastating condition, and it's understandable that parents want to do everything they can to help their children. But while the evidence pointing to a possible immune system response to gluten in some children is interesting, it's too preliminary to offer any real-world treatment strategies.

If your child has digestive symptoms (as many children with autism do), your child's doctor can point to potential causes and treatments. If celiac disease runs in your family and your autistic child has celiac disease symptoms, you could consider testing for celiac disease. At this time, unfortunately, there's no testing available for non-celiac gluten sensitivity, but if you think the gluten-free diet might help your autistic child, discuss the pros and cons of the diet with your healthcare provider.