Celiac.com 03/22/2010 - The main cause for gluten intolerance continues to puzzle scientists, but pathogenesis theories include both genetic susceptibility and environmental triggers, like a virus or infection.
For the first time, scientists working with the Academy of Finland’s Research Program on Nutrition, Food, and Health have found genes in the body that are associated both with the immune system and with the body's ability to properly digest gluten in the intestinal tract.
Gluten intolerance arises from an autoimmune reaction in the small intestine to the gluten protein found in wheat, barley and rye. Academy Research Fellow Paivi Saavalainen, a veteran researcher in hereditary risk factors for gluten intolerance, says that "some of the genes we have identified are linked with human immune defense against viruses. This may indicate that virus infections may be connected in some way with the onset of gluten intolerance.”
Data shows that rates of celiac disease in America have increased more than 400% since World War II. Meanwhile, a Finnish scientist internationally known for his gluten research says that the number of people in Finland who suffer from gluten intolerance has doubled over the last two decades.
Since the early 1980s, the percentage of Finns with gluten intolerance has risen from about 1 percent of adults to about 2 percent, according to Professor Markku Mäki, head of a research project in the Academy of Finland's Research Program on Nutrition, Food and Health.
"We've already seen a similar trend emerge earlier on where allergies and certain autoimmune disorders are concerned. Screening has shown that gluten intolerance occurs in 1.5 per cent of Finnish children and 2.7 per cent of the elderly. The higher figure for older people is explained by the fact that the condition becomes more frequent with age," says Mäki.
For the immune study, when researchers scanned the genetic maps of more than 9400 celiac patients, they found areas of immune system disturbance. Their evidence also indicated that genes connected with the inability to digest gluten were also connected with other autoimmune diseases such as type 1 diabetes and rheumatoid arthritis.
Saavalainen and his team have succeeded in localizing risk genes in both individual patients and entire families, which adds weight to the notion that gluten intolerance is inherited.
The researchers are hoping to use the genetic information to craft better screening tests for gluten intolerance, as up to 75% of people with gluten intolerance remain undiagnosed due to mild or atypical symptoms, and many with condition may unwittingly suffer damage to their intestinal villi. Professor Maki points out that many present first with iron deficient, or folic acid deficient, anemia.
Academy of Finland