primary prevention of coeliac disease - Associazione Italiana ...

48 INFANT FEEDING PRACTICES AND COELIAC DISEASE
infants were breast-fed for six months or longer. As a result, most of the infants were
introduced to cow's milk products and other food products while still being breast-fed.
Also, for most infants the termination of breast-feeding did not coincide with
introduction of infant formula, but rather with increased ingestion of other foods.
Moreover, in the case-referent study we could show that a reduced risk for coeliac
disease still remained when the age of the infants at introduction of gluten into the diet
was considered, along with the amount of gluten given at that time (fig. 2). Thus, our
findings strongly supported breast-feeding as directly reducing the risk for coeliac
disease, and not merely influencing the risk indirectly through changes in other
exposures.
It has recently been suggested that the intestinal lesion in coeliac disease might be
caused by an uncontrolled production of pro-inflammatory IFN-gby intraepithelial T
cells that is not sufficiently counteracted by an increased production of downregulating
TGF-b1 (Forsberg G, personal communication). It is thus tempting to
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speculate that the TGF-b1 in breast-milk compensates for this although this is only
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one of several possible mechanisms for a protective effect of human milk .
Thus, a protective effect of being breast-fed when dietary gluten is introduced is
supported by several epidemiological studies of different design. Moreover, the
protective effect is biologically plausible when taking into account our present
knowledge of breast-milk composition and the impact on immune responses, and the
aetiology of coeliac disease.
Amount of dietary gluten
The dose of dietary antigen ingested may influence whether or not oral tolerance
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develops . It is not yet clear if this applies to the amount of gluten given in relation to
the risk of developing coeliac disease.
Interestingly, a larger consumption of wheat gluten was reported for healthy infants
in Sweden and Italy as compared to Finland, Denmark and Estonia, and the former
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countries also reported a higher occurrence of coeliac disease . The study designs,
involving aggregated data, did not, however, allow adjustments for differences in other
exposures.
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The Swedish case-referent study by Fälth-Magnusson et al indicated that the
coeliac disease cases, more often than the referents, were introduced to gluten by means
of gluten-containing follow-on formula. In infancy it is clear that bottle-feeding,
compared to feeding by cup and spoon, more readily contributes a larger amount of
food, and thus also a larger amount of gluten. In the Fälth-Magnusson study, however, it
was not possible to estimate the amount of gluten given to the infants.
In our case-referent study it was possible, for the first time, to assess the
consumption of gluten-containing cereals on an individual basis by use of a semi-
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quantitative food frequency questionnaire . We could show that introduction of glutencontaining
foods in larger amounts, as compared to small or medium amounts, was an
independent risk factor for coeliac disease development (adjusted OR=1.5, 95% CI 1.1-
2.1). Also, at seven months of age the cases consumed larger amounts of glutencontaining
flour than the referents. It is important to note that through the use of
multivariate analyses we adjusted for differences in breast-feeding practices and the