The goal of this study was to identify the frequency of physician-diagnosed food allergies among 6-year-old US children and study the impact of exclusive breastfeeding and complementary food introduction on this frequency.
Data were analyzed from children who participated in the Infant Feeding Practices Study II Year 6 Follow-Up Study (Y6FU). Children with probable food allergy (pFA) were defined as children with report of physician-diagnosed food allergy at age 6 years. Subgroups of pFA included children who were not diagnosed before 1 year of age (new pFA) and those with atopic risk factors (high risk).
Prevalence of total pFA in the Y6FU was 6.34%. The majority of these children had new pFA and high-risk factors. Higher maternal education, higher family income, family history of food allergy, and reported eczema before 1 year of age were significantly associated with higher odds of total or new pFA. Exclusive breastfeeding duration and timing of complementary food introduction were not significantly associated with total pFA. However, exclusive breastfeeding of ≥4 months compared with no breastfeeding was marginally associated with lower odds of new pFA (adjusted odds ratio: 0.51; P = .07); this effect was not observed with high-risk children.
Analysis of infant and maternal variables in the Y6FU cohort of US children revealed that socioeconomic and atopic factors were the main predictors of pFA at age 6 years. Exclusive breastfeeding of ≥4 months may have a preventive effect on development of pFA after 1 year of age in non high-risk children.