Prolonged breastfeeding appears to offer some babies major intestinal benefits, a new Swedish study finds. The practice prevented or at least delayed the onset of celiac disease in children.

This intestinal disorder tends to run in families, especially those with a northern-European background. In the United States, roughly one in every 250 Americans develops the condition, which is an autoimmune reaction triggered by the consumption of the protein gluten from wheat, barley, rye, or oats.

When symptoms are mild and restricted to upset stomach, weight loss, diarrhea, fatigue, and gassiness, the condition usually goes undiagnosed. In severe cases, however, the symptoms can prove devastating and even life threatening.

The majority of symptoms trace to changes in the surface of the small intestine. Ordinarily, tiny fingerlike projections, called villi, cover its surface. Theyre the conduit through which the gut absorbs nutrients. With celiac disease, those villi disappear over time–as long as the sufferer continues to include breads, pasta, cereals, and even beer in his or her diet. Ignored in this way, bad cases can lead to serious malnutrition, regardless of how much other food a person eats.

Though celiac disease can develop at any age, it often occurs after periods of stress. Anneli Ivarsson and her colleagues at the University of Ume in Sweden have been homing in on factors that seem to foster early development of the disease. In the May American Journal of Clinical Nutrition, they report a strong relationship between celiac disease and both breastfeeding and a babys introduction to cereal-based foods.

Probing an epidemic

Between 1985 and 1987, Sweden experienced a fourfold spike in the incidence of celiac disease among children under age 2. The increase put the rate of that disease in Sweden to levels higher than had been reported for any other country. After 1995, the incidence returned to historic levels.

In an attempt to understand what lay behind the earlier epidemic, Ivarssons team collected national data on length of breastfeeding, cereal intake by children at weaning, and medical recommendations on how to wean babies. They looked for changing trends in these features throughout a 2-decade period that spanned the epidemic.

Their findings suggested that longer breastfeeding protected against early onset of the disease, as did a very gradual introduction of gluten-rich cereal products.

To confirm those findings, the scientists surveyed mothers for details of their weaning of 627 children that had developed the disease. Though some of the childrens celiac disease had been diagnosed during adolescence, 80 percent of the cases emerged before a child had turned 2. The researchers then matched each child to two healthy ones of the same age and sex, and they administered the same questionnaire to these parents. The Ume epidemiologists never mentioned that their study was focusing on celiac disease.

Their new analysis shows that waiting until a child is at least 7 months old before introducing flour products cut the risk of developing celiac disease by roughly 25 percent, when compared with introducing cereals at an earlier age.

In Sweden, most women breastfeed their babies for at least 6 months. Whether a mother regularly breastfed right up until she began introducing flour-based foods–usually in the form of wheat-fortified infant formulas–also influenced celiac incidence. Doing so cut the chance that a child would develop the disease by 40 percent, as compared with children weaned from the breast earlier. And when a woman continued breastfeeding beyond her babys introduction to flour-containing foods, her childs risk of celiac disease fell by 65 percent, compared with babies weaned early.

Finally, the researchers made rough measurements of how much cereal Swedish parents initially gave to their babies, either as fortified infant formula or as solid foods (bread, crackers, porridge, and pasta). Regardless of how the cereal was delivered over an initial 2-week period, introducing it in small-to-medium amounts, rather than large amounts, cut a childs risk of developing celiac disease by fully 33 percent. (Amounts of foods given children werent measurable from the survey, just mothers estimates of whether quantities were typically small, medium, or large.)

Extended breastfeeding and a gradual introduction of gluten-containing cereals were independently protective, though breastfeedings benefit was roughly twice the magnitude of that from slowly introducing children to cereal. Together, these factors accounted for 45 percent of the risk of celiac disease among the Swedish children, the scientists say–meaning that almost half of the cases among the youngsters might have been prevented.

Still to be answered, the scientists note, is whether those cases would have been eliminated or just postponed.

Other predisposing risks

As large as the impacts of these weaning factors appear to have been, they dont rank as highly as certain other predisposing risks. Chief among these, according to a paper in the May Pediatrics, is childhood (type 1) diabetes.

In a new 6-year study, researchers in Milan, Italy found that when compared with nondiabetic children, those having diabetes faced 20 times the risk of celiac disease. Some 60 percent of the celiac cases in these children had been present–though undiagnosed–at the time their diabetes was discovered.

As a result, the authors conclude, “Extending screening programs for celiac disease after the onset of type 1 diabetes is recommended, even in the absence of clinical symptoms.”

“Why should we be concerned” about finding asymptomatic celiac disease? asks Linda S. Book of the University of Utah Department of Pediatrics in Salt Lake City. In a commentary accompanying the Pediatrics paper, she points out that celiac disease may not only complicate the management of diabetes but also reduce weight gain by altering the nutrients available from the diet.

At least as importantly, she notes, celiac disease has been associated with several other diseases–such as lymphoma, osteopenia (loss of bone density or mass), and cancer–not to mention complications of pregnancy. Cutting gluten from the diet can reduce or eliminate these complications of celiac disease, Book observes.

As such, she argues, celiac disease “is a more common disease than previously thought, and its diagnosis and treatment have much broader implications than management of a malabsoptive disorder.”

Janet Raloff

Janet Raloff is the editor of Science News for Students, a daily online magazine for middle school students. She started at Science News in 1977 as the environment and policy writer.

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