TUESDAY, May 31, 2016 (HealthDay News) -- New research has revealed some surprising findings about who develops celiac disease in the United States.
The study found that it's most common among people whose ancestors came from India's Punjab region. Previously, experts thought celiac mostly affected white people with European ancestry.
Celiac also seems to affect men and women equally, regardless of ethnicity, the researchers said.
"It is now recognized as one of the most common hereditary disorders worldwide," said the study author, Dr. Benjamin Lebwohl, in a news release from the American Gastroenterological Association. Lebwohl is an assistant professor of medicine and epidemiology at the Celiac Disease Center at Columbia University Medical Center, in New York City.
Celiac is an immune-based disorder that causes damage to the small intestine if genetically susceptible people eat foods containing gluten, according to the Celiac Disease Foundation (CDF). Gluten is a protein found in wheat, barley and rye, as well as foods containing these substances.
Celiac disease affects about 1.8 million Americans, the researchers said.
But the disease is often misdiagnosed, the CDF said. The diagnosis is confirmed through a biopsy of tissue from the small intestine, the researchers said.
"Our findings help shed light on the distribution of celiac disease in the U.S. and will aid gastroenterologists in diagnosing their patients," Lebwohl said.
For this study, the researchers looked at data from more than 400,000 intestinal biopsies. The researchers also used patient names to help them figure out the distribution of the disease. The distribution included a number of ethnicities, such as North Indian, South Indian, East Asian, Hispanic, Middle Eastern, Jewish and other Americans.
Along with finding high rates of the disease in people from the Punjab region of India, the researchers also found the condition was much less common among Americans from South Indian, East Asian and Hispanic ancestry.
Meanwhile, people with Jewish and Middle Eastern ethnicities had rates of the disease similar to that of other Americans.
The study also showed no difference in male and female rates of celiac disease across all ethnic groups. That's important because previous studies have suggested that celiac may be more common in women. Researchers said doctors might not look for the disease as much in men.
"Based on our findings we recommend that physicians consider celiac disease in men as often as they consider it in women," Lebwohl said.
The study was published in Clinical Gastroenterology and Hepatology.
The U.S. National Institute of Diabetes and Digestive and Kidney Diseases provides more information on celiac disease.