Giving gluten-containing foods to infants too soon may trigger long-lasting tummy troubles but more study is needed before changing recommendations for parents, Dutch researchers conclude.

Writing in the American Journal of Gastroenterology, J. C. Kiefte-de Jong and colleagues at the Erasmus Medical Center in Rotterdam report that 2-year-olds introduced to gluten before 6 months of age had a “significantly higher” rate of “functional” constipation - defined as fewer than 3 bowel movements per week and/or hard stools for 2 or more weeks - than children who were introduced to gluten later.

At the same time, introducing other allergy-inducing foods in the first year of life such as peanuts, cow’s milk, or hen’s eggs was not linked to constipation.

Gluten is a protein found in wheat, barley and rye and, as a result, is present in many cereals and breads. It is not present in all grains, however. Wild rice, corn, buckwheat, millet, amaranth, quinoa, oats, soybeans, and sunflower seeds do not contain gluten protein.

Earlier studies implied a relationship between early gluten introduction and celiac disease, a digestive disorder caused by an abnormal immune response to gluten. The disease damages structures in the lining of the small intestine called villi, impairing the body’s absorption of nutrients.

It can lead to severe health problems including anemia, poor bone health, fatigue and weight loss. There is no cure, and the only treatment is a life-long gluten-free diet.

The authors wanted to know whether gluten might also be linked to constipation, which is the main reason for up to 5 percent of all visits to pediatricians. It often develops around the time solid foods are added to an infant’s diet, and when parents transition from breast milk or formula to cow’s milk.

The Dutch researchers analyzed data from more than 4,600 children from birth until young adulthood. Parents completed a questionnaire at 6 and 24 months about their child’s general health, breast feeding, the introduction of solid foods, medications, cow’s milk allergy and other information.

At 24 months, 12 percent - about one in eight - of the study’s children had functional constipation.

After examining family traits and diets, Kiefte-de Jong concluded that introducing gluten in the first year of life was “a trigger for functional constipation” in some children. On the flip side, constipation may make cow’s milk allergies last longer.

Still, researchers said the study had some weaknesses, including the need to rely on self-reporting by parents about food allergies and the lack of information about lifestyles and psychological factors, and said they would want to see more studies before making any new recommendations to parents.

Dr. Rita Steffen, a pediatric gastroenterologist at Cleveland Clinic Children’s Hospital, agreed.

Parents are usually urged to introduce solids slowly, starting with rice cereal and moving to other grains after 6 months, Steffen told Reuters Health, while acknowledging that parents will do what they want, often jumping the gun on introducing other solids.

If a child is tolerating gluten, Steffen said, there’s no reason yet to remove it from the diet.

“I wouldn’t jump out and change the world based on this,” she said. “There’s not enough evidence to support removing gluten from diets.”

SOURCE: American Journal of Gastroenterology, March 2010.