These are dietary regimens that limit or eliminate certain food groups to improve symptoms related to ASD. These diets are based on the theory that some foods or dietary components can influence behavior, gut health, or autism symptoms.
Some examples of restrictive diets include the following:
- Gluten-Free, Casein-Free Diet (GFCF): This is one of the most popular diets for treating autism and focuses on eliminating gluten and casein. It is based on the hypothesis that some people with ASD have difficulty digesting these proteins, producing by-products that may affect behavior and brain functions.
- Ketogenic Diet: High in fats, moderate in protein, and low in carbohydrates, this diet was initially designed to treat epilepsy. It is believed that this diet might influence brain metabolism and, consequently, reduce some behavioral symptoms of autism.
- Dye-Free, Preservative-Free, and Additive-Free Diet: This diet removes artificial additives found in many processed foods, as it is suggested that these additives could impact the behavior of individuals with ASD.
Why do some people use these therapies to treat autism?
Some studies indicate that people with ASD are more likely to suffer from gastrointestinal problems such as diarrhoea, constipation, or food intolerance. Others believe that people with ASD have a more "permeable" gut, which allows unwanted substances to enter the bloodstream and affect the brain. Lastly, research has explored the possible relationship between autism and chronic inflammation, as well as the impact of the gut microbiome (intestinal bacteria) on neurological and behavioral symptoms.
What does the evidence say?
So far, the most restrictive diets for autism lack conclusive scientific evidence supporting their effectiveness in treating ASD symptoms. Some studies suggest improvements in certain symptoms, but results are inconsistent, and not all children or adults with autism respond the same way.
Additionally, if not managed properly, many of these diets can lead to nutritional deficiencies.
In any case, dietary changes should be made under the supervision of a healthcare professional, such as a nutritionist or doctor.