(HealthDay) -- Migraine headaches are more likely to plague people with celiac disease than those without it, according to new research.
The connection between the digestive tract and the brain has been studied in Europe, but this is the first time American researchers have linked celiac disease and other bowel problems with migraines, said study co-author Dr. Alexandra Dimitrova.
"We found significantly higher prevalence of headaches in patients with celiac disease compared to those without it," said Dimitrova, a neurology resident at the Neurological Institute at Columbia University Medical Center in New York City.
Celiac disease is an autoimmune disease that affects one out of every 133 people in the United States, according to the Celiac Disease Foundation. People with the condition can't eat pizza, pastries and other foods that contain wheat gluten. Symptoms include stomach problems, joint pain and headaches.
Neurologic manifestations of celiac disease have been described since the 1960s, and poor coordination and subtle sensory loss are among the symptoms commonly reported, Dimitrova said.
The researchers also looked at two other related conditions. More than 1.5 million Americans have Crohn's disease or ulcerative colitis, the most common forms of inflammatory bowel disease, according to the Mayo Clinic. Both conditions inflame the lining of the intestines and can cause bouts of diarrhea, rectal bleeding and abdominal cramps, as well as pain, fever and weight loss.
For the study, Dimitrova and her colleagues surveyed more than 700 people using a four-page questionnaire. A detailed medical history was logged, which included whether a participant had been diagnosed with celiac disease or inflammatory bowel disease, or had problems eating foods containing wheat. Researchers also asked about headache history. Lifestyle details -- such as smoking, alcohol and coffee habits -- also were documented.
"We ended up analyzing 502 people," Dimitrova said. "We eliminated those who had head trauma or brain tumors, everybody who drank more than two alcoholic beverages a day and people who drank four or more cups of coffee a day -- anything that could be headache contributors."
The yearlong study found that 188 people had celiac disease, 111 had inflammatory bowel disease and 25 were gluten-sensitive -- meaning they had not tested positive for celiac disease but reported symptoms when they ate foods with wheat. The other 178 healthy individuals served as the control group.
Chronic headaches of any kind were reported by 56 percent of gluten-sensitive participants, 30 percent of those with celiac disease and 23 percent of those with inflammatory bowel disease, while only 14 percent of the control group reported headaches.
Dimitrova said that when the researchers screened specifically for migraines, 21 percent of those in the celiac group and 14 percent of the inflammatory bowel disease group met the criteria for the sometimes disabling headaches, compared with only 6 percent of the control group.
"Our findings suggest that migraine is a common neurologic manifestation in celiac disease, gluten sensitivity and [inflammatory bowel disease]," said Dimitrova, who also said they don't know what the mechanism is.
"It's possible the patients with [inflammatory bowel disease] have a generalized inflammatory response, and this may be similar in celiac disease patients, where the whole body, including the brain, is affected by inflammation," she said. "The other possibility is that there are antibodies in celiac disease that may ... attack the brain cells and membranes covering the nervous system and somehow cause headaches. What we know for sure is that there is a higher prevalence of headache of any kind, including migraine headaches, compared to healthy controls."
Dr. Alessio Fasano, medical director of the University of Maryland Center for Celiac Research in Baltimore, said it is not unusual to hear his patients with celiac disease complain of headaches.
"Roughly one-third of celiac disease or gluten-sensitive patients we see have some form of migraine," Fasano said. "That link with gluten-related disorders is very well known to us. We don't know why. What is the connection?"
Dimitrova said many patients reported major improvements in the frequency and severity of headaches once they adopted a gluten-free diet.
Fasano said he has seen it work the other way around, too, in that people with migraines often also complain of belly woes and some experience less digestive trouble when they go on gluten-free diets.
"One thing is for sure: Many people with migraines, when they go on a gluten-free diet, the migraines improve or go away," he said.
Migraine sufferers who don't get relief from treatments should ask their doctors about a celiac disease screening, Dimitrova said.
The researchers presented their findings last week at the American Academy of Neurology annual meeting in New Orleans. The data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.
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The U.S. National Library of Medicine has more about celiac disease.