primary prevention of coeliac disease - Associazione Italiana ...

INFANT FEEDING PRACTICES AND COELIAC DISEASE
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age of the infant when gluten was introduced into the diet. Thus, our findings clearly
indicate that introduction of gluten in larger amounts increases the risk for coeliac
disease. Furthermore, we found that the type of food used as the source of gluten, i.e.
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solid foods or follow-on formula, was not important as an independent risk factor . The
relevance of our observations is therefore not only applicable to Sweden with its custom
of using gluten-containing follow-on formula from the age of six months.
The daily amount of gluten consumed during infancy as a risk factor for coeliac
disease is further supported by our ecological study of the Swedish epidemic, where we
used aggregated data to explore any temporal relationship between changes in
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incidence rate and changes in infant dietary patterns . The rise in incidence was
preceded by a twofold increase in the average daily consumption of gluten through the
use of follow-on formula, and later, the fall in incidence coincided with a consumption
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that was decreased by one-third .
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Marsh et al concluded that gluten-sensitised individuals respond in a time-related
and dose-dependent fashion to gliadin, which is an observation supported by several
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other studies . These experimental studies do not, however, clarify whether the
amount of gluten is also crucial when infants are introduced to this antigen for the first
time.
Taken together, there is evidence to suggest that consumption of a large amount of
gluten-containing flour (increased antigen dose) during infancy increases the risk for
coeliac disease. It is, however, not clear whether there is a direct dose-response effect or
a threshold effect. Furthermore, it seems likely that the amount of gluten tolerated
varies with the genetic predisposition of the individual, other environmental exposures,
and the age of the individual.
Age at introduction of gluten
There might be an age interval during which humans have decreased ability to
develop oral tolerance to a newly introduced dietary antigen. Hypothetically, the age of
the infant upon introduction of gluten into the diet might thus influence the risk for
coeliac disease.
In a comparison of English coeliac disease patients in the 1950s and 1960s, it was
suggested that earlier introduction of dietary gluten resulted in earlier presentation of
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the disease . Some clinical studies in which differences in breast-feeding duration
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have been taken into account did not show such a relationship . In fact, a delayed
introduction of gluten into the diet of infants was suggested as contributing to the
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decline in incidence of coeliac disease in England, Scotland and Ireland in the 1970s .
However, at that time comparable dietary changes occurred in Sweden without any
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observed change in incidence . Furthermore, the increased incidence in Swedish
children in the middle of the 1980s was preceded by a delayed introduction of dietary
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gluten from four until six months of age . Thus, these ecological observations
resulted in contradictory findings. However, a study design based on aggregated data
cannot by itself provide conclusive evidence.
However, the case-referent design based on individual data allows for adjustments
for differences in other exposures. Such studies in which adjustments have been made
for differences in breast-feeding duration have indicated that the age of the infant at