The age at which babies are introduced to foods with gluten doesn't affect their risk of developing celiac disease, a new study finds.

Earlier studies had suggested that introducing gluten between the ages of four and six months might lower the risk of celiac disease, a condition in which gluten in food triggers a damaging immune response in the small intestines.

But in this new study, children introduced to gluten before age 17 weeks or after 26 weeks were not at an increased risk of developing celiac disease, compared to those who were introduced to the protein between those ages, researchers found.

Carin Andrén Aronsson, the study’s lead author from Lund University in Malmö, Sweden, said parents should still follow the general recommendation for introducing children to gluten.

“For Europe anyway you should introduce gluten in small amounts at four to six months of ages,” she said. “I think we can still stick with that.”

In the U.S. and Europe, about one in 100 people have celiac disease. If they consume wheat, barley or rye, or foods that contain those grains, their immune response leads to intestinal damage, malnutrition and other problems.

As reported in the journal Pediatrics, Aronsson's group used data from a study of type I diabetes in children from Sweden, Finland, Germany and the U.S. They followed 6,436 children with a genetic predisposition for celiac disease.

On average, children in Sweden were introduced to gluten at about age 22 weeks. Kids in Finland were started on gluten a bit later, at 26 weeks. Those in Germany and the U.S. were introduced to gluten even later, at about 30 weeks, on average.

After five years, 773 children had a marker of celiac disease known as tTGA (tissue transglutaminase antibody) in their blood, and 307 actually developed celiac disease – based on an intestinal biopsy or consistently high tTGA levels.

Overall, children with a specific genetic predisposition, those born in Sweden, females and kids with a family history of celiac disease were more likely to develop the condition.

After adjusting for those factors, there was no link between when the children were introduced to gluten and their risk of developing celiac disease.

The researchers did find that children in Sweden are more likely to develop celiac disease, compared to children in the U.S. Based on the results, the researchers suggest it may be due to an interaction of gluten and weaning, but that result needs more research.

Currently, the American Academy of Pediatrics recommends that women exclusively breastfeed their newborns for six months after birth. Then, they should continue breastfeeding for one year or more as they introduce other foods.

Around the world, the incidence of celiac disease is increasing, but researchers still don’t know why, said Dr. Peter Green, director of the Celiac Disease Center at Columbia University.

“We have to address the reason,” said Green, who was not involved with the new study.

He also said the new study, with the support of previous research, does not suggest that people need to follow any specific recommendation about gluten introduction.

Two other recent studies also found that timing of gluten introduction to a baby's diet doesn’t protect them from celiac disease (see Reuters Health story of October 1, 2014 here: reut.rs/17XPgud.)

Green said the new results can probably apply to the general population, but cautioned “they’re not studying the general population.” Instead, this research involved high-risk children.