Researchers recently set out to determine the prevalence and incidence of autoimmune diseases in people with anorexia nervosa, bulimia nervosa and binge eating disorder. 

Patients (N=2342) treated at the Eating Disorder Unit of Helsinki University Central Hospital between 1995 and 2010 were compared with general population controls (N=9368) matched for the age, sex and place of residence. Data of 30 autoimmune diseases were from the Hospital Discharge Register from 1969 to 2010.

They found that somatic illnesses, such as eating disorders, presented an autoimmune etiology such as type 1 diabetes and inflammatory bowel diseases. In addition, a prior autoimmune disease has recently been shown to increase the risk of mood disorders and schizophrenia.

Study sample by diagnostic groups with lifetime prevalence figures of autoimmune diseases covering the time before, during, and after the treatment for an eating disorder. doi:10.1371/journal.pone.0104845

"We found that of patients with eating disorders, 8.9% had been diagnosed with one or more autoimmune diseases. Of the control individuals, the number was 5.4%," says Dr. Anu Raevuori from the University of Helsinki, about the analysis by the University of Helsinki, Helsinki University Central Hospital and National Institute for Health and Welfare, Finland. 

The increase in endocrinological diseases was explained by type 1 diabetes, whereas Crohn's disease contributed most to the risk of gastroenterological diseases.

The higher prevalence of autoimmune diseases among patients with eating disorders was not exclusively due to endocrinological and gastroenterological diseases; when these two categories were excluded, the increase in prevalence was seen in the patients both before the onset of the eating disorder treatment and at the end of the follow-up.

"Our findings support the link between immune-mediated mechanisms and development of eating disorders. Future studies are needed to explore the risk of autoimmune diseases and immunological mechanisms in individuals with eating disorders and their family members," Raevuori states.