The objective of this chapter is to evaluate the research pertinent to the use of dietary interventions to treat autism. A brief description, rationale, any evidence of efficacy and validity of methodology employed for most frequently used inventions in autism follows.
The number of children diagnosed with autism spectrum disorder (ASD) has increased significantly over the last decades in the U.S. and in other countries. Yet to date, there is no clear etiology or cure for autism. In most cases, specific underlying causes cannot be identified (Cubala-Kucharska, 2010). A number of risk factors being investigated include genetic, infectious, metabolic, nutritional and environmental, but less than 10 to 12% of cases have specific causes known (Srinivasan, 2009). Simultaneously the use of alternative treatment approaches in children with autism has increased, but due to significant methodological flaws, the currently available data are inadequate to guide treatment recommendations (Christison and Ivany , 2006).
It has been suggested that nutritional factors play a major role. 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 (Elder, 2008). In practice, treatment of ASD usually consists of a comprehensive program of educational intervention, speech therapy, behavioral treatment and developmental therapies. 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 (Cubala- Kucharska,2010; Srinivasan, 2009 ). The popularity of these diets indicates a need for more in-depth and rigorous research into their efficacy.
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 (Seung et. al, 2007). 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 (Elder, 2008). The literature currently available suggests that diets removing both gluten and casein show some efficacy and should be studied further.