The Effect of Bisphenol A on Puberty: A Critical Review of the Medical Literature

Abstract

Many scientific studies have revealed a trend towards an earlier onset of puberty and have disclosed an increasing number of children that display precocious puberty. As an explanation, some authors have considered the global socio-economic improvement across different populations, and other authors have considered the action of endocrine disrupting chemicals (EDCs). Among these, bisphenol A (BPA), an aromatic compound largely used worldwide as a precursor of some plastics and chemical additives, is well known for its molecular oestrogen-like and obesogenic actions. We reviewed the medical literature of the previous 20 years that examined associations between BPA exposure and the age of puberty in humans, considering only those referring to clinical or epidemiological data. Of 19 studies, only 7 showed a correlation between BPA and puberty. In particular, the possible disruptive role of BPA on puberty may be seen in those with central precocious puberty or isolated premature breast development aged 2 months to 4 years old, even if the mechanism is undefined. Some studies also found a close relationship between urinary BPA, body weight, and early puberty, which can be explained by the obesogenic effect of BPA itself. The currently available data do not allow establishment of a clear role for BPA in pubertal development because of the conflicting results among all clinical and epidemiological studies examined. Further research is needed to fully understand the potential role of exposure to EDCs and their adverse endocrine health outcomes.

Evidence of the Possible Harm of Endocrine-Disrupting Chemicals in Humans: Ongoing Debates and Key Issues

“…In fact, in contrast to the conclusion of official reports on EDCs [ 1 2 5 ], many recent systemic reviews or meta-analyses focusing on epidemiological studies, especially of short-lived EDCs, seem to support the opponents' position. For example, reviews of the effects of bisphenol A (BPA) in humans reported conflicting results with respect to pubertal development [ 22 ] and diabetes [ 23 ]. Similar conclusions have been reached on phthalate and obesity [ 24 ], triclosan and diverse health effects [ 25 ], and developmental exposure to many EDCs and male reproductive disorders [ 26 ].…”

Assessing Endogenous and Exogenous Hormone Exposures and Breast Development in a Migrant Study of Bangladeshi and British Girls

“…Despite some differences in urinary concentrations of BPA and estrogens between the groups, our study found limited evidence that these concentrations explained the association between exposure to the UK environment and earlier thelarche. Evidence concerning the relationship between BPA and pubertal outcomes has been mixed [11]. Several toxicological studies have reported that early exposure to low doses of BPA altered the development of rodent mammary glands, which manifested from the time of exposure and was exacerbated at puberty and beyond [31].…”

“…Animal models suggest BPA demonstrates estrogenic activity [8], accelerates pubertal onset [9], and increases mammary cancer risk [10]. However, epidemiological evidence between BPA and puberty has been mixed [11]. Nevertheless, the World Health Organization commissioned a report in 2012 on endocrine-disrupting chemicals and recommended research should investigate whether early-life exposures are associated with changes in the timing of pubertal events [12].…”

Molecular and Environmental Mechanisms Regulating Puberty Initiation: An Integrated Approach

“…For example, in rats, neonatal exposure to BPA for 2 weeks led to delayed puberty at a low dose, but earlier puberty when a higher dose was administered. Similarly, lower doses of phthalates were associated with early puberty, whereas the opposite effect was observed with higher doses (39). Second, timing of exposure has a substantial effect on the final outcome.…”