Dec. 12, 2013 -- It’s not unusual for people to say they feel much better after dropping gluten from their diets, even though they don't have celiac disease, digestive experts report.
What these people describe has come to be called “non-celiac gluten sensitivity,” or NCGS. It's a little-studied diagnosis that has contributed to the growing market for gluten-free products, expected to surpass $6.2 billion worldwide by 2018, according to one estimate.
NCGS is “a wildly popular topic on the Internet,” says Douglas Seidner, MD. “There’s a lot of discussion, a bit of confusion.”
Seidner is director of the Center for Human Nutrition at Vanderbilt University. He spoke about the gluten controversy last Saturday at a meeting of the American Society for Nutrition.
In celiac disease, eating a protein in wheat, rye, and barley called gluten triggers inflammation in the small intestines.
The problem is that little is known about NCGS, from how much gluten is needed to trigger symptoms to whether gluten is even the culprit, Seidner says. Meanwhile, he says, many people are eliminating gluten from their diets because they think it will improve their health, even if they don’t have celiac disease.
Gluten helps bread rise and gives bread, pasta, noodles, and other wheat products elasticity and appealing texture.
About 1 in 100 people worldwide has celiac disease. The only treatment is a gluten-free diet. When someone with celiac disease eats even tiny amounts of gluten, their immune system attacks the the lining of the small intestine. This can lead to malnutrition.
No one knows how common NCGS is, Seidner says, but it could affect as many as 6 out of every 100 people. NCGS is a separate condition from celiac disease, and it’s not known if people with the former will ever go on to develop the latter, he says. Despite the condition’s name, “gluten may not be the only dietary compound in wheat” that leads to NCGS, Seidner says.
Both conditions have intestinal symptoms, such as bloating and pain, and symptoms outside the digestive tract, such as fatigue. A small percentage of people with irritable bowel syndrome have either celiac disease or NCGS as well, Seidner says.
Celiac disease runs in families, while NCGS doesn’t appear to, he says.
There are only three published studies to refute or support the diagnosis of NCGS, Seidner says.
Italian doctors who published a study last year of 920 of their patients concluded that some people who don’t have celiac disease are indeed sensitive to wheat. But some were sensitive to multiple foods as well as wheat, the researchers said.
The two other studies were done by a team of Australian scientists. They reached two different conclusions.