Schoetzau A, Filipiak-Pittroff B, Koletzko S, von Berg A, et al. Pediatr Allergy Immunol. 2002;13:234–242
Purpose of the Study.
To evaluate whether there is a preventive effect of exclusive breastfeeding and early solid food avoidance on the incidence of atopic dermatitis (AD). Sensitization to milk and egg allergens were also considered as secondary endpoints.
A total of 1121 healthy newborn infants with a family history of atopy recruited from maternity wards who were exclusively breastfed or received cow’s milk formula (CMF) during the first 16 weeks of life.
This was a prospective cohort study comparing the incidence of AD in the first year of life between infants who were exclusively breastfed and infants who were exclusively or supplementarily formula-fed with CMF during the first 16 weeks of life. The effect of early solid food avoidance in the incidence of AD was evaluated as well as the incidence of egg and milk sensitization. At study entry, mothers were encouraged to exclusively breastfeed for at least 4 months, and solid foods were discouraged during this same time period. If breastfeeding was not possible, difficult, or refused, infants received formula exclusively or as a supplement. The mothers recorded weekly dietary diaries during the first 24 weeks of life. Mothers were asked to record the type of milk, time of introduction of milk, and types of foods consumed during this time period. Infants were seen by a physician at 1, 4, 8 and 12 months or between visits if skin lesions were observed and suspicious for AD. Blood was obtained at birth, 4 months, and 12 months for total immunoglobulin E (IgE) and specific IgE for milk and egg allergens.
Eight hundred sixty-five infants were exclusively breastfed and 256 received CMF during the study period. There were significant differences between the 2 study groups. The breastfed group had significantly higher atopic risk based on family history, higher level of parental education, less maternal postnatal smoking and lower prevalence of pets in the home. At 1 year, 9.5% of the breastfed group and 14.8 of the CMF group had AD (P = .015). Age at first introduction of solids or diversity of foods given in the first 24 weeks did not seem to affect the incidence of AD. There was no difference between groups for milk or egg sensitization; however, infants with AD were more likely to be sensitized (4 times for milk and 8 times for egg) than those without AD. Risk factors for AD included increased number of core family members with AD, double atopic risk (both parents) and cord blood IgE levels above detection (0.35 kU/L). Participants with pets in the home had a significantly lower incidence of AD than those without pets.
Despite higher atopic risk, the incidence of atopic dermatitis was significantly lower in infants exclusively breastfed during the first 16 weeks of life as compared with infants receiving CMF during this same time period. Neither the age at first introduction of solids nor the diversity of solids fed during the first 16 weeks seemed to increase the incidence of AD.
Breastfeeding is widely accepted as the ideal source of nutrition for newborn infants, and the current study provides evidence that exclusive breastfeeding for the first 4 months of life may reduce the risk of AD in individuals with high atopic risk. As observed in this study, mothers of infants with a history of atopy were more likely to breastfeed exclusively, creating a significant difference between groups at baseline. Therefore, the protective effect of exclusive breastfeeding may not be applicable to the general population. Delay of the introduction of solids did not affect the incidence of AD in the current study. All participants received detailed information regarding the benefits of delayed solid food avoidance and avoidance of highly allergenic foods; therefore, the percentage of infants fed solids and diversity of foods received during the study period was low in both groups. Significant differences may have been observed between groups in both the incidence of AD and sensitization to milk and egg if the percentage of infants receiving solids was higher or more allergenic foods were introduced. Future prospective studies should be conducted to evaluate the long-term preventive effects of breastfeeding beyond 4 months of life, particularly in atopic populations.