The risks of gluten allergies have been underestimated, according to a study that found increased mortality rates among people with coeliac disease.
Coeliac disease is triggered by exposure to gluten, a protein found in wheat, rye and barley.
Found in about 1% of the Western population, it damages the small intestines and interferes with the absorption of nutrients from food.
People with coeliac disease often also have other diseases that attack the immune system such as diabetes or arthritis.
However, coeliac disease often goes undiagnosed until substantial damage has been done to the digestive system.
Risk 'modestly increased'
Using data taken from biopsies taken between July 1969 and February 2008 in Sweden, researchers were able to examine the overall risk of death in individuals with coeliac disease and digestive inflammation and compare it to the general population.
They found the risk of death was "modestly increased". Patients with inflammation had a 72% increased risk of death; patients with coeliac disease had a 39% increased risk; and patients with latent coeliac disease had a 35% increased risk of death.
Lead author Jonas Ludvigsson of the Orebro University Hospital concluded that there could be several explanations for the increased mortality risks.
"Malnutrition of energy and vitamins and chronic inflammation may increase the risk of death," he wrote, noting that even patients who maintain gluten-free diets have persisting lesions.
Coeliac disease: an important diagnosis
Those with inflammation who had not been diagnosed with coeliac disease may have an overall worse prognosis because institution of a gluten-free diet often leads to normalisation, the authors concluded.
"Until recently, gluten sensitivity has received little attention in the traditional medical literature, although there is increasing evidence for its presence in patients with various neurological disorders and psychiatric problems," Peter Green of Columbia University College of Physicians and Surgeons wrote in an accompanying editorial.
"The study by Ludvigsson and colleagues reinforces the importance of coeliac disease as a diagnosis that should be sought by physicians. It also suggests that more attention should be given to the lesser degrees of intestinal inflammation and gluten sensitivity."
The risk of death was highest in the first year of follow-up but decreased with age at diagnosis, with risk being higher for those diagnosed before age 20.
The study was published in the Journal of the American Medical Association.
(Sapa, September 2009)