What is it?

A gluten-free diet is an eating plan in which gluten (a protein found in some grains) is eliminated from the diet. Foods and drinks containing wheat, barley, rye, or anything made from these grains are avoided. A gluten-free diet is often used for children with autism in combination with a casein-free diet. The casein-free diet calls for the elimination of milk protein (casein). Both diets are called elimination diets because a particular type of food is eliminated from the child’s meals and snacks ⁽¹⁾.

Proponents of the gluten-free diet say that many children with autism have gastrointestinal difficulties that make it hard for them to digest certain grains properly. There are different possibilities for ways in which this could affect children with autism. The most studied theory is that eating gluten leads to high levels of protein by-products, called gluteomorphines, in some children with autism. These by-products may then affect behavior like a drug would. Specifically, in these children, gluteomorphines could reduce their desire for social interaction, block pain messages, and increase confusion. If gluten is taken out of the diet, the idea is that this will reduce the level of gluteomorphines, and behavior will improve as a result ^(2-4).