The relationship of autism and gluten.

BACKGROUND: Autism is now a common condition with a prevalence of 1 in 88 children. There is no known etiology. Speculation about possible treatments for autism or autism spectrum disorders (ASD) has included the use of various dietary interventions, including a gluten-free diet.
OBJECTIVE: The goal of this article was to review the literature available evaluating the use of gluten-free diets in patients with autism to determine if diet should be instituted as a treatment.
METHODS: A literature review was performed, identifying previously published studies in which a gluten-free diet was instituted as an autism treatment. These studies were not limited to randomized controlled trials because only 1 article was available that used a double-blind crossover design. Most publish reports were unblinded, observational studies.
RESULTS: In the only double-blind, crossover study, no benefit of a gluten-free diet was identified. Several other studies did report benefit from gluten-free diet. Controlling for observer bias and what may have represented unrelated progress over time in these studies is not possible. There are many barriers to evaluating treatment benefits for patients with autism. Gluten sensitivity may present in a variety of ways, including gastrointestinal and neurologic symptoms. Although making a diagnosis of celiac disease is easier with new serology and genetic testing, a large number of gluten-sensitive patients do not have celiac disease. Testing to confirm non-celiac gluten sensitivity is not available.
CONCLUSIONS: A variety of symptoms may be present with gluten sensitivity. Currently, there is insufficient evidence to support instituting a gluten-free diet as a treatment for autism. There may be a subgroup of patients who might benefit from a gluten-free diet, but the symptom or testing profile of these candidates remains unclear.