In the United States, celiac disease is four times more common now than it was in the 1950's, according to a study by researchers at the Mayo Clinic in Rochester, Minnesota.
The Mayo Clinic study also found that people who didn't know they had celiac disease were nearly four times more likely than people without celiac disease to have died during the 45 years of follow-up.
"Some studies have suggested that for every person who has been diagnosed with celiac disease, there are likely 30 more who have it but are not diagnosed," senior author Dr. Joseph Murray noted in a statement from the Mayo Clinic.
"And given the nearly quadrupled mortality risk for silent celiac disease we have shown in our study, getting more patients and health professionals to consider the possibility of celiac disease is important," Murray added.
Celiac disease, which is the intolerance of wheat protein (gluten), resulting in symptoms such as frequent diarrhea and extreme weight loss, "is emerging as a substantial public health concern in the United States," Murray and colleagues warn in the latest issue of the journal Gastroenterology.
In an interview with Reuters Health, Dr. Alberto Rubio-Tapia, who was involved in the research, said, "The reasons for the increasing prevalence of celiac disease over time will need further study. The most likely explanation may be environmental."
One possible explanation is the hygiene hypothesis - the theory that the increasingly germ-free surroundings of modern life are actually contributing to an increase in allergies and asthma and abnormal immune system reactions.
"Recent data from Europe support this theory in celiac disease," Rubio-Tapia pointed out.
"However," he continued, "I think that the 'hygiene hypothesis' is likely only a partial explanation because celiac disease is a global health problem that affects both developed and developing countries." Also, there is evidence that certain infections may increase the risk of celiac disease in genetically predisposed individuals.
Additionally, because celiac disease is triggered by gluten, changes in gluten such as patterns of consumption, processing or preparation of gluten-containing foods might be involved.
Ultimately, Rubio-Tapia concluded, "the increasing prevalence of celiac disease over time may be the result of several of (these) factors acting together to cause damage of the intestine in genetically susceptible persons."
For their study, the Mayo Clinic team tested blood samples gathered at Warren Air Force Base (AFB) in Wyoming between 1948 and 1954 for the antibody that people with celiac disease produce in reaction to gluten. They compared those blood test results with those from two recently collected sets from Olmsted County, Minnesota. One matched the ages of those from the 1948 testing at the time of the blood draw, and the other matched their birth years.
Researchers found that young people today are 4.5 times apt to have celiac disease than young people were in the 1950s, while those whose birth years matched the Warren AFB participants were four times more likely to have the disease.
Similar increases in cases of celiac disease have been reported in Europe.