By Serena Gordon
In the study, pregnant women who had the highest consumption of gluten had double the risk of having a child with type 1 diabetes compared to those who ate the least gluten. Gluten is a protein found in wheat, rye and barley.
However, the study authors noted that it's too soon to recommend that pregnant women change their diets based on the results of this one study.
"The study brings new ideas to how type 1 diabetes develops. We did not know that the pregnancy period is important for the development of the disease [or] that the development of the disease is starting that early in life," said study co-author Dr. Knud Josefsen.
"And it also holds the potential to reduce the frequency of the disease by simply changing the diet during pregnancy," added Josefsen, a senior researcher at the Bartholin Institute in Copenhagen, Denmark.
However, "the study is observational and the link that we describe is an association," and not a cause-and-effect relationship, Josefsen said. The research also needs to be repeated in other populations.
Type 1 diabetes is an autoimmune disease that causes the body's immune system to mistakenly attack the insulin-producing cells in the pancreas, according to JDRF (formerly Juvenile Diabetes Research Foundation). Insulin is a hormone that helps usher the sugar from foods into the body's cells to be used as fuel.
The attack on the immune system cells leaves someone with type 1 diabetes with little to no insulin. Without insulin injections -- via multiple shots a day or an insulin pump -- someone with type 1 diabetes doesn't have enough insulin to survive.
Gluten is found in many foods -- including bread, pasta, cereal, crackers and cookies -- according to the Celiac Disease Foundation. Gluten triggers the immune system disorder called celiac disease that causes damage to the small intestine when gluten is consumed.
There's already a known link between celiac disease and type 1 diabetes -- approximately 10 percent of people with type 1 diabetes also have celiac disease, Josefsen said.
The latest study included data from almost 64,000 pregnant women enrolled from 1996 through 2002. Nearly 250 of these women's children developed type 1 diabetes.
The women answered questions about the foods they ate when they were 25 weeks' pregnant.
The average gluten intake was 13 grams per day. The range was less than 7 grams per day to more than 20 grams per day. Josefsen said a slice of bread has about 3 grams of gluten. A large serving of pasta -- about two-thirds of a cup -- has 5 to 10 grams of gluten, he said.
The researchers found that a child's risk of type 1 diabetes increased proportionally with every 10 grams of the mother's daily gluten intake.
Josefsen said there are some theories as to how gluten might contribute to the rise of type 1 diabetes. One is that gluten may cause inflammation and an immune response.
Maija Miettinen, co-author of an editorial that accompanied the study, said most of the theories as to how these two conditions might be related come from animal models. Like Josefsen, she said more research is needed.
"This is the first study to suggest an association between high gluten intake during pregnancy and the risk of type 1 diabetes in the offspring. Therefore, it is too early to change dietary recommendations concerning gluten intake," she said. Miettinen is a researcher with the National Institute for Health and Welfare in Helsinki, Finland.
Miettinen also pointed out that women who have high-gluten diets in pregnancy may also continue to serve their children high-gluten fare. "We do not know whether the possible risk associated with high gluten intake comes through prenatal exposure, childhood diet or both," she said.
The study was published online Sept. 19 in the BMJ.