By Van Waffle
Summary: Case studies have suggested a link between celiac disease and autism, but the relationship remains controversial. Autistic children are sometimes placed on a restrictive, gluten-free diet in hope of altering their behavior. However, larger research projects have found no relationship. A new, nation-wide Swedish study provides some of the strongest evidence so far.
Researchers analyzed health records of 290,000 people who received biopsies to look for intestinal tissue damage. Of these, 27,000 were diagnosed with celiac disease. Another 12,300 had inflammation but not celiac disease and 3,700 had positive celiac blood screening but normal biopsy results. The team compared the rates of autism in all these groups. Patients diagnosed with celiac disease were matched by age, sex and location with similar people who showed no indicators for the disease. Celiac patients were no more likely to have a previous diagnosis of autism than those in the general population.
In additional analysis, the study compared patients’ risk of developing autism later on. In this case, patients with celiac disease were about 40 per cent more likely to be diagnosed with autism. However, the researchers suggest caution about this finding, as it does not prove celiac disease causes autism.
Conclusion: Among the most extensive studies to date on celiac disease and autism, this one does not find a correlation. Interestingly, patients with a positive blood test for celiac antibodies but no intestinal damage, and thus no diagnosis of celiac disease, showed a significantly higher incidence of autism. The antibodies may occur due to other gastrointestinal issues. This suggests more research is needed to investigate a link between gut health and autism. However, the study calls into question the practice of treating autism with a highly restrictive gluten-free diet unless celiac disease has been diagnosed.
 “A nationwide study of the association between celiac disease and the risk of autistic spectrum disorders”, Ludwigsson JF, Reichenberg A, Hultman CM, Murray JA, JAMA Psychiatry 2013 Sep 25 [Epub ahead of print].