Gluten-free/casein-free diet (GF/CF)—Grade: B
This diet is a popular alternative treatment for autism, based on the premise that the proteins gluten (found in wheat) and casein (in milk) aggravate autistic symptoms because they in some way mimic opiate neuropeptides. One small single-blind trial found some improvements; larger double-blinded trials have found none. Hyman and Levy speculate that improvements seen by parents may be from removing lactose from the diets of children who are lactose intolerant.
Source: Levy, S.E. & Hyman, S.L. Child Adolesc. Psychiatr. Clin. N. Amer. 17, 803-820 (2008).
Child Adolesc Psychiatr Clin N Am. 2008 October; 17(4): 803–ix. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2597185/?tool=pubmed