Reduced Risk of Peanut Sensitization Following Exposure Through Breastfeeding and Early Peanut Introduction

Abstract

To evaluate the relationship between maternal consumption of peanut while breastfeeding, the timing of direct oral peanut introduction, and sensitization to peanut at 7 years of age.The study included 342 children from the Canadian Childhood Asthma Primary Prevention Study who had a family history of asthma or immunoglobulin E–mediated allergic disease.A secondary analysis of the Canadian Childhood Asthma Primary Prevention Study cohort was performed. Pregnant women were recruited and randomly assigned to a multifaceted intervention group or a control group. The control group received no specific maternal or infant diet instructions. Mothers in the intervention group were asked to do the following: (1) avoid peanuts, nuts, fish, and eggs during pregnancy and while breastfeeding; (2) breastfeed for 4 to 12 months; (3) avoid introducing solid foods to infants until after 6 months of age; and (4) delay the introduction of allergenic foods until at least 12 months of age. Maternal and infant diet questionnaires were completed at 2 weeks and 4, 8, 12, 18, and 24 months of age. At 7 years of age, children had skin prick testing to peanut performed.Of 342 children, 32 (9.4%) were sensitized to peanut by 7 years of age, with no significant difference seen between study groups. The lowest incidence of peanut sensitization (1.7%) was found when mothers consumed peanut while breastfeeding and infants were introduced to peanuts in their diet before 12 months of age; an interaction analysis was used to confirm that this combination was protective. Isolated exposure to maternal peanut consumption while breastfeeding or infant peanut introduction before 12 months of age was associated with an increased risk of peanut sensitization (adjusted odds ratio 12.45 [95% confidence interval 1.18–131.30] and adjusted odds ratio 8.30 [95% confidence interval 1.05–65.80], respectively).We found that peanut introduction before 12 months of age combined with maternal peanut consumption while breastfeeding was associated with the lowest risk of peanut sensitization by 7 years of age compared with maternal or infant peanut consumption in isolation.The Learning Early About Peanut Allergy study revealed that in high-risk infants, early peanut introduction reduced the risk of peanut allergy. The impact of maternal peanut consumption during pregnancy or while breastfeeding remains unclear. This study revealed that the group with maternal peanut consumption while breastfeeding, combined with early peanut introduction to the infant, yielded a reduced risk of peanut sensitization at 7 years of age. However, researchers also found that early peanut consumption alone led to a marked increase in peanut sensitization, which would appear contradictory to the Learning Early About Peanut Allergy study. This study has several limitations, including sample size, incomplete and limited dietary information, and a lack of oral food challenges used to diagnose peanut allergy. Furthermore, research is clearly needed before suggesting any changes to our current recommendations.