Zutavern A, von Mutius E, Harris J, et al. Arch Dis Child. 2004;89:303–308
Purpose of the Study.
Some feeding guidelines recommend delayed introduction of solids for the prevention of asthma and allergy. This study sought to explore whether late introduction of solids is protective against the development of asthma, eczema, and atopy.
A total of 642 unselected children recruited before birth and followed to the age of 5.5 years.
A questionnaire was administered yearly. Food exposure was derived from the first-year questionnaire: “When did you start feeding your son/daughter the following foods?: fruits, vegetables, infant rice, cereal products, meat, fish, milk products, egg.” Median age at which each solid food was introduced and length of time the infant was breastfed were determined. Wheezing was defined as wheezing in the absence of a cold or infection in the preceding 12 months, and eczema was defined as a positive response to “has a doctor ever told you that your son/daughter has eczema?” Skin-prick tests to grass, cats, and dust mites were performed at age 5.5 years, and atopy was defined as at least 1 positive skin test. Clinical outcomes were compared for early (before the median age) or late (after the median age) introduction of foods and how long the infants were breastfed.
No effect of the early or late introduction of solid foods in relation to any of the outcomes was observed. No association between exclusive breastfeeding at the age of 8 weeks and any of the outcomes was found.
The results do not support the recommendations given by present feeding guidelines, which state that a delayed introduction of solids is protective against the development of asthma and allergy.
Published feeding guidelines on the delayed introduction of solid foods to prevent allergy state that “conclusive studies are not yet available to permit definitive recommendations.” Nonetheless, recommendations are made regarding delaying the introduction of certain foods until certain ages. Some meta-analyses have favored breastfeeding for prevention of eczema (and other atopic diseases), but individual studies on both sides continue to be published. This study suggests that delayed introduction of solid foods does not prevent asthma, eczema, or atopy. The most obvious type of allergy that such a delay might prevent is allergy to the food itself, but this “prevention” is somewhat self-fulfilling, because you cannot become allergic to a food to which you have not been exposed. This is complicated further by exposure to foods in breast milk. Additionally, many toddlers who become allergic to foods, particularly milk and egg, routinely outgrow the allergy. Although this study is helpful in examining the relationship (or lack thereof) between the introduction of solid foods and asthma, eczema, and atopy, we need more research to tell us if delayed introduction of solid foods will prevent or merely delay the development of food allergy.