Age of introducing cereal grains to infants and the risk of wheat allergy

Foods containing the cereal grains wheat, barley rye and oats are usually not given to  infants until after 6 months in order to reduce the risk of allergy   A recent study, looking at the age introduction of cereal grains and the development of wheat allergy has found that delaying the introduction cereal grains beyond 6 months of age may actually increase the risk of developing wheat allergy.

1612 children were enrolled at birth and followed to age 4.7 years. Children with coeliac disease were excluded from the study. Parents reported on the presence of allergy during telephone and face to interviews. Of the 958 children (59%) percent of children, introduced to cereal grains before 6 months, 4 (0.4%) developed wheat allergy. Six hundred and fifty four children (41%) had their first exposure to cereals after 6 months and of these 12 (1.8%) exhibited wheat allergy ie 4 times as many as those introduced to cereals before 6 months.  The  association of increased prevalence of wheat allergy with introduction of cereal grains after 6 months held true even after controlling for family history of allergy, breastfeeding duration, prior food allergy and introduction of rice cereal. The study also showed that having a first degree relative with a history of hives, asthma, and eczema was independently associated with increased risk of wheat allergy.

The results may be partly explained by the induction of immune tolerance. There may be a specific time when exposure of a foreign food protein or antigen could promote immune tolerance and that to maintain tolerance continuous exposure to the antigen is required. Late exposure causing wheat allergy in the older child could be explained by the larger quantity eaten, resulting in T cell activation rather than tolerance

The study does not support delaying introducing cereal grains to protect against food allergy.

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Reference:

Poole JA, Barriga K et al. Timing of Initial Exposure to Cereal Grains and Risk of wheat allergy.  Paediatrics 2006; 117(6):2175-2181