Celiac disease, a condition in which the body can't digest gluten, is not just a disorder you're born with. You can develop it as you get older, too, a new study suggests.
The autoimmune disease has long been thought to develop in childhood and to be unpreventable. But researchers followed more than 3,500 people over 30 years and found that the incidence of celiac disease grew as the population aged. This means environmental factors may play a role in the development of the disease.
"You're never too old to develop celiac disease," study researcher Dr. Alessio Fasano, of the Center for Celiac Disease Research at the University of Maryland, said in a statement.
Gluten is a protein found in wheat, barley and rye. Celiac disease symptoms include diarrhea , intestinal bloating and stomach cramps, and if the disease is left untreated, it can lead to an inability to absorb nutrients, damage to the small intestine and medical complications.
Since 1974, the incidence of the disorder has doubled every 15 years in the United States, the researchers said.
Researchers found the number of people with markers for celiac disease in their blood increased from 1 in 501 people in 1974 to 1 in 219 people in 1989, the study said. The blood markers are used as a way to diagnose the disease.
In 2003, 1 in 133 people had celiac disease, according to other research from the Center for Celiac Disease Research.
Although researchers have identified specific genetic markers for the development of celiac disease, exactly how and why an individual loses their ability to tolerate gluten remains a mystery.
"Even if you have these genetic markers, it's not your destiny to develop an autoimmune disease," Fasano said. "Our study shows that environmental factors cause an individual's immune system to lose tolerance to gluten, given the fact that genetics was not a factor in our study since we followed the same individuals over time."
Identifying these environmental factors could lead to treatment and even prevention of celiac disease, and could possibly also shed light on other autoimmune disorders including Type 1 diabetes, rheumatoid arthritis and multiple sclerosis, the researchers said.
The study was published today (Sept. 27) in the journal Annals of Medicine.
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