Friendly fire: gluten intolerance is surprisingly hard to identify.(Celiac disease diet therapy)

In times of war, when people are accidentally killed by their allies, it's known as "friendly fire." Autoimmune disease is similar in that one's own immune system can misfire and wreak havoc on any one of a number of bodily systems.

Celiac disease--also known as celiac spree, gluten sensitive enteropathy (GSE) or gluten intolerance--is one such condition.

In celiac disease, the immune system targets gluten, a protein found in wheat, rye and barley. When gluten is ingested, the immune system reacts to it as if it were a pathogen, attacking it inside the small intestine. The collateral damage of this attack includes the villi--tiny, hair-like projections that absorb nutrients. When the villi are damaged, nutrients can't be absorbed, and malnutrition becomes a risk.

While this seems fairly straightforward, gluten intolerance can be difficult to diagnose because it presents itself as a number of different conditions, including irritable bowel syndrome, Crohn's disease, diverticulitis, or even chronic fatigue syndrome or depression, according to the National Institute of Diabetes & Digestive & Kidney Diseases (NIDDK), a branch of the National Institutes of Health (NIH).

Prevalence

Perhaps because it is difficult to diagnose, celiac disease was believed to be uncommon in the United States until recently. In February 2003, Alessio Fasano, MD, and a team from the University of Maryland, Baltimore, published evidence in the Archives of Internal Medicine suggesting that celiac disease is more prevalent than once thought. Their study of 13,145 subjects indicated that 1 in 133 people suffers from the condition, and because it is a genetic disorder, it is much more common in those who have first- and second-degree relatives who also have it.

According to Fasano, this finding was a "storm" released onto the scientific community. "[T]here were two key factors," Fasano explains. "For each individual diagnosed, there were roughly another 50 undiagnosed. And second, the lag between the onset of the symptoms and the time of diagnosis was roughly 12-13 years. These were two statements that really prompted the scientific and medical communities to regroup and reconsider."