Peanut and tree nut consumption during pregnancy and allergic disease in children-should mothers decrease their intake? Longitudinal evidence from the Danish National Birth Cohort.

BACKGROUND: The relation between maternal peanut intake during pregnancy and allergic disease development in children has been controversial.

OBJECTIVE: We used data from the Danish National Birth Cohort to examine associations between maternal peanut and tree nut intake during pregnancy and allergic outcomes in children at 18 months and 7 years of age.

METHODS: We estimated maternal peanut and tree nut intake (n = 61,908) using a validated midpregnancy food frequency questionnaire. At 18 months, we used parental report of childhood asthma diagnosis, wheeze symptoms, and recurrent wheeze (>3 episodes). We defined current asthma at 7 years as doctor-diagnosed asthma plus wheeze in the past 12 months and allergic rhinitis as a self-reported doctor's diagnosis. We also used alternative classifications based on registry-based International Classification of Diseases, Tenth Revision, codes and drug dispensary data. We report here odds ratios (ORs) comparing intake of 1 or more times per week versus no intake.

RESULTS: We found that maternal intake of peanuts (OR, 0.79; 95% CI, 0.65-0.97) and tree nuts (OR, 0.75; 95% CI, 0.67-0.84) was inversely associated with asthma in children at 18 months of age. Compared with mothers consuming no peanuts, children whose mothers reported eating peanuts 1 or more times per week were 0.66 (95% CI, 0.44-0.98) and 0.83 (95% CI, 0.70-1.00) times as likely to have a registry-based and medication-related asthma diagnosis, respectively. Higher tree nut intake was inversely associated with a medication-related asthma diagnosis (OR, 0.81; 95% CI, 0.73-0.90) and self-reported allergic rhinitis (OR, 0.80; 95% CI, 0.64-1.01).

CONCLUSIONS: Our results do not suggest that women should decrease peanut and tree nut intake during pregnancy; instead, consumption of peanuts and tree nuts during pregnancy might even decrease the risk of allergic disease development in children.