Autism & Diet

For many years the connection between a GFCF diet and improvement of autism symptoms was anecdotal at best and based upon the experiences of a handful of parents. However, over the past twenty years the scientific evidence of such an association has burgeoned.

What is the physiological basis of the connection between autism and gluten and casein intolerances and allergies? Research has shown that some autistic individuals lack the ability to completely break down gluten and casein proteins within their digestive systems. The peptides that result from this incomplete breakdown leak through the intestinal walls (which are particularly permeable in autistic people) giving it the term “leaky gut syndrome.” These peptides travel through the bloodstream to the brain where they can have opiate effects that can mimic neurological disorders and may cause developmental delays.

Research also indicates that a significant number of autistic individuals show signs of an immune response to gliadin which is one of the proteins found in wheat. People who have Celiac’s disease (which is caused in part to an allergy to wheat) also have high levels of antibodies formed in response to gliadin. This suggests a possible correlation between wheat allergies and autism. In fact, a study published in 2002 by Harvard University researchers found that approximately half of the autistic people they examined had some sort of intestinal issues or food allergies.

The effect of diet on autism has been strengthened by genetic research. It is well known that an individual, particularly a twin, has a higher chance of being autistic if another sibling has the disorder. Currently, a group of scientists known as the Autism Genetic Resource Exchange is actively researching potential links between genetics and autism. In March of 2009 members of this research consortium published in the journal Pediatrics the results of a study showing a specific gene present both in people with intestinal disorders and those with autism spectrum disorders, thus linking the two conditions.

It is important to note that while many of the allergies are blamed on proteins found in wheat, there seems to be a link between casein proteins found in dairy products. In fact, just over half of the autistic individuals that took part in one study were found to have a deficiency of lactase, which is the enzyme responsible for breaking down the lactose found in milk.

For many autistic individuals, adopting a GFCF diet can help with symptoms but should not be expected to completely eliminate them (although in mild cases it has been known to do so). While the GFCF diet has helped a number of children, there are individuals that have experienced little to no change when placed on this diet. However, a study published in a 2002 issue of Nutritional Neuroscience found that the development of children placed on a GFCF diet was significantly better than the development of children placed on a normal diet which strengthens the arguments for a GFCF diet. Research is still needed to determine the magnitude of the effect that can be expected from switching to a GFCF diet as well as estimates of the number of people such a switch would help.

Essentially, learning of a connection between gluten and casein allergies or intolerances and autism has changed the lives of many children and their parents. Many parents who have switched their autistic children to gluten- and casein-free diets have noticed remarkable changes in their children’s symptoms. For those parents, a connection between a GFCF diet and autism, whether anecdotal or scientific, is real and invaluable.