Can A Gluten-Free/Casein-Free Diet Really Make A Difference For Autistic Children?

Parents of autistic children are, research shows, some of the most frustrated people out there. They're more stressed, more frustrated with their children's behavior, more angry, face more difficulties in caring for their children, and feel they sacrifice more than both parents of typically-developing children and parents of children with other developmental disorders.

In a situation where you feel like you can't relate to your own child, can't seem to do anything to control their behavior, and your whole life starts revolving around worries and limitations, wouldn't you do anything you could just to make things a little bit better? Many parents of autistic children do. In the age of ubiquitous wifi, that often begins with the internet.

Sooner or later, parents of autistic children in search of answers will come across claims that diet can make a huge difference. The so-called gluten-free/casein-free diet is especially popular, with some proponents claiming it will help nearly all autistic children, and some even going so far as to say that it can cure this actually life-long neurodevelopmental condition. 

What is a gluten-free/casein-free diet?

• Gluten is a collection of proteins found in grains like wheat, barley, spelt, rye, and triticale — or, in other words, foods like bread and other pastries, pasta, and cereal, but also soups, sauces, salad dressings, and a whole bunch of other things you wouldn't usually associate with grains. It's the "glue" that holds these foods together. Though some people, notably those with celiac disease, have a very legitimate reason to avoid gluten, gluten-free diets have gained traction well beyond this population in recent times. One 2013 survey even found that almost a third of Americans wanted to either cut down on gluten or eliminate it from their diets altogether. 
• Casein is a complete protein — offering all the essential amino acids — that makes up 80 percent of the protein found in milk. Digested slowly, it can help people lose fat and build muscle. It's no wonder that the bad reputation gluten has gathered in recent times hasn't generally rubbed off on this protein. 

Casein and gluten do share something important in common — both are broken down into "exorphins" that have opioid properties (kind of like endorphins, but rather than being produced inside the body, they come from outside).

The GFCF diet was originally developed in a bid to reduce symptoms in people with schizophrenia. The idea behind it, that gastrointestinal leakage or permeability could interfere with brain functioning in this group of people, was at least partly based on someone's — perhaps erroneous — observations that some indigenous societies in which people tend to consume these compounds much less often also have fewer and milder cases of schizophrenia. 

Google "gluten-free/casein-free diet" today, however, and the results the search engine presents you with will overwhelmingly focus on its supposed benefits for people with autism ― with many websites claiming that this diet will boost autistic people's social and language skills "in most cases". 

Is there any scientific reason to believe the GFCF diet does anything for autistic people?

Some. But the studies that have been done so far haven't been very convincing. 

While one study found that autistic people are indeed more likely to have gastrointestinal permeability, another found no differences between autistic and neurotypical folks in this area. While some research has found that autistic people have higher levels of peptides in their urine, others reached the conclusion that this is not true. 

Research backing the idea that a gluten-free/casein-free diet leads to a reduction in the severity of autism symptoms have largely been based on self-reports from parents and teachers, meanwhile. Some of this research sounds incredibly hopeful, a portion of parents whose children were placed on this diet declared them "cured" of autism and said that previously non-verbal autistic children suddenly acquired speech while their communication skills sky-rocketed. Knowing that a child was on this diet and hoping it would work, however, they may have fallen victim to confirmation bias. A well-designed double-blind study, in which parents had no idea whether or not their kids were in the GFCF diet group, found that the diet made no difference. 

What are the risks of a GFCF diet?

A strong preference or need for sameness and routine is one of the defining characteristics of autism spectrum disorder. It is no wonder, then, that many autistic people have limited diets, preferring to eat the same short list of foods over and over again. Where this is true for an individual autistic person, they're already at risk of nutritional deficiencies. 

That's a lot of potential problems for a diet that's never been proven to "improve the symptoms of autism". We'd advise parents to never single-handedly commit to this or any other "autism diet", but to have a serious talk with their child's doctor — nope, not a naturopath or homeopath — before they even think about implementing it in their own home.