Influence of exposure to endocrine disruptors and other environmental chemicals on breast development in girls: A systematic review of human studies

Background

Age at thelarche has decreased over recent decades. This change in female puberty timing may be influenced by exposure to endocrine disrupting chemicals (EDCs) during critical periods of development.

Objective

To review the scientific literature for evidence on the association of exposure to EDCs and other environmental chemicals with the timing of thelarche in girls.

Methods

A systematic search for original peer-reviewed articles published up to July 2023 was conducted in three databases (Medline/PubMed, Scopus, and Web of Science), following the PECO strategy and PRISMA guidelines. The quality of evidence and reporting and the risk of bias were evaluated using GRADE, STROBE, and ROBINS-E tools.

Results

Out of 3094 articles retrieved in the search, 67 met the review inclusion criteria. Data from 10 out of the 14 studies offering high-quality suggest that in utero and/or childhood exposure to certain synthetic and natural chemicals is associated with earlier breast development in girls; 8 of these 10 studies described a relationship with exposure to organohalogenated compounds in utero and to phthalates in childhood.

Conclusions

This systematic review provides the first overview of available human data on the association of EDCs/environmental chemicals with the timing of thelarche. Further high-quality research is urgently needed to fully elucidate the influence of this exposure on breast development timing in girls.