JAMA Netw Open

Exclusive breastfeeding linked to lower risk of precocious puberty

August 20, 2025

Study details: A nationwide, retrospective cohort study in South Korea analyzed health data from 322,731 children (58.1% girls) born between 2007 and 2010. Feeding practices during the first 4 to 6 months of life were categorized as exclusive breastfeeding, formula feeding, or mixed feeding. Primary outcome: central precocious puberty (CPP), identified via diagnostic codes and treatment records.

Results: Exclusive breastfeeding during early infancy was associated with a lower risk of CPP in both boys and girls compared with those who were formula-fed (adjusted hazard ratio [aHR], 1.16 in boys; 1.60 in girls) or mixed-fed (aHR, 1.14 in boys; 1.45 in girls). Mediation analysis revealed that prepubertal adiposity accounted for 7.2% of the association in boys and 17.8% in girls.

Clinical impact: These findings underscore the role of early-life nutrition in shaping pubertal timing. Promoting exclusive breastfeeding may help reduce the risk of early puberty and its associated long-term health risks, particularly in girls. Consider infant feeding practices and early weight trajectories as part of anticipatory guidance and obesity prevention strategies.

Source:

Choe Y, et al. (2025, August 18). JAMA Netw Open. Breastfeeding, Prepubertal Adiposity, and Development of Precocious Puberty. https://pubmed.ncbi.nlm.nih.gov/40824636/