Association between maternal dietary isoflavone consumption during pregnancy and childhood food allergy in offspring: The Japan Environment and Children's study

BACKGROUND: Isoflavone (ISO) consumption during pregnancy may affect food allergy (FA) in offspring through estrogen-like and other biological effects; however, this ISO-FA association in mother-child pairs remains elusive. Herein, the maternal ISO-childhood FA association was investigated using the Japanese birth cohort data. METHODS: The data from the Japan Environment and Children's Study, including 86,012 and 75,307 mother-child pairs, with FA in children aged ≤1 year and 1-3 years, respectively, were analyzed. Maternal ISO consumption (total daidzein and genistein) was assessed using a food frequency questionnaire. Physician-diagnosed FA data were obtained using questionnaires completed by caregivers. ISO consumption data was categorized into quartiles (Q1: reference), and the ISO-FA association was assessed through multivariable logistic regression analysis after adjusting for maternal age, educational level, smoking status, pre-pregnancy body mass index, history of allergies, blood folic acid concentration, total energy intake, and infant feeding method up to 4 months of age. RESULTS: Overall, FA cases in children aged ≤1 and 1-3 years were 6.6% and 12.1%, respectively. Maternal ISO consumption was negatively associated with FA in all children aged ≤1 year (Q3, adjusted odds ratio [aOR]: 0.91, 95% confidence interval [CI]: 0.84-0.99; Q4, aOR: 0.86, 95% CI: 0.79-0.93) and in those aged 1-3 years (Q3, aOR: 0.93, 95% CI: 0.88-0.99; Q4, aOR: 0.88, 95% CI: 0.83-0.95). Furthermore, in sex-stratified analysis, a negative association was observed between maternal ISO consumption and FA in female children of all ages, whereas this inverse association was observed only in 1-3-year-old male children. CONCLUSIONS: Overall, the findings show that maternal ISO consumption during pregnancy may reduce the risk of childhood FA, exhibiting sex-difference effects on offspring development.