The findings suggest that the higher incidence of this autoimmune disease may be related to a combination of seasonal and environmental factors.
Celiac disease is a digestive disorder triggered by consuming the protein gluten, which is primarily found in bread and other foods containing wheat, barley or rye. It can damage the small intestine and make it difficult to absorb certain nutrients, causing problems ranging from abdominal pain to nerve damage.
Examining data on 382 Massachusetts children diagnosed with celiac disease at between 11 months and 19 years of age, researchers found that in the 15- to 19-year-old set, birth season appeared to make no difference. But among 317 children younger than 15 years of age, 57 percent were born in the "light" season of March through August, compared with 43 percent who were born in the "dark" season of September through February.
Even though the exact cause of celiac disease is unknown, potential triggers include the timing of infants' introduction to gluten, and viral infections contracted during the first year of life. The study's findings suggest the season of a child's birth is another potential risk factor for the disease.
The researchers pointed out that infants are generally introduced to solid foods containing gluten at around 6 months of age, which for spring and summer babies would coincide with cold and flu season.
Based on the findings, the study's lead researcher, Dr. Pornthep Tanpowpong, said that the age at which gluten is first offered to some babies may need to be altered.
"If you're born in the spring or the summer, it might not be appropriate to introduce gluten at the same point as someone born in the fall or winter," said Tanpowpong. "Although we need to further develop and test our hypothesis, we think it provides a helpful clue for ongoing efforts to prevent celiac disease."
The study also noted that exposure to sunlight may also play a role in celiac disease, since vitamin D deficiency has been associated with the disease.
The study is slated for presentation Sunday in Chicago during Digestive Disease Week, an international gathering sponsored by the American Gastroenterological Association and other organizations.
Because the study was presented at a medical meeting and is small, its findings should be considered preliminary until published in a peer-reviewed journal and confirmed in other research.