Significantly lower levels of various nutrients in blood have been observed in autistic children including low levels of zinc, selenium, vitamin D and omega-3 fatty acids. Anecdotal reports and parent surveys and a few research studies have indicated some evidence of diminishing the symptoms of autism by use of diets based on food elimination and rotation, as well as through supplementation and alternative treatments based on intestinal healing.
Currently a variety of nutritional interventions are in use, including gluten and casein- free diet (GFCF), ketogenic diet, yeast free diet, restriction of food allergens, probiotics, and dietary supplementation with vitamins A, C, B6, folic acid, B12, minerals like magnesium and omega-3 fatty acids. In most cases, the dietary interventions discussed below were developed for conditions related to autism, e.g., multiple food sensitivity, inflammatory bowel disease, Candida and viral infections. Wide use of complementary and alternative therapies (CAM) by parents and caregivers has been reported. The literature currently available suggests that diets removing both gluten and casein show some efficacy and should be studied further.
Gluten –Free Casein- Free Diet (GFCF)
One of the most frequently used interventions for ASD is the GFCF diet. Initially focusing on schizophrenia, investigators conducted studies to test the hypothesis that schizophrenia as well as autism was in some way associated with the absorption of “exophrins” contained in gluten and casein. This diet calls for complete elimination of both gluten and casein, which is found in wheat, rye, barley, and oats, as well as casein, the protein in milk and all milk products.
The ketogenic diet was first introduced as a therapeutic method to reduce the number and intensity of epileptic seizures. But it has been reported that in addition, the ketogenic diet is beneficial for mental behavior and hyperactivity. In the classic ketogenic diet, also known as the long-chain triglyceride diet, fat provides the majority of energy, protein is based on minimum daily requirements, and carbohydrates are severely restricted
This diet is based on the benefit of a food-restriction diet for attention deficit and hyperactivity disorder. Scientifically undocumented behavioral improvements after elimination of food colors and flavors have been reported. According to Dr. Feingold’s hypothesis elimination of food additives resulted in some cases in dramatic decline in hyperactive symptoms
Antioxidant diets have gained the attention of some investigators who are concerned about oxidative stress in autism and related conditions. Commonly recommended foods are fresh fruits and vegetables, cooked legumes, and whole grains.
Among the dietary interventions currently in use for treatment of ASD, the gluten-free-casein free diet shows the most promise of efficacy.
References: Yasmin Neggers "Autism Spectrum Disorders - From Genes to Environment" edited by Tim Williams, ISBN 978-953-307-558-7, InTech, September 9, 2011