DURHAM, USA – A new study has identified a potential link between environmental chemicals and the increasingly early onset of puberty in girls, an issue that has puzzled scientists for decades.
The research, conducted by a team at the National Institute of Environmental Health Sciences (NIEHS), suggests that musk ambrette, a compound found in a variety of everyday products, may trigger a brain signal that starts puberty.
The study, led by Dr Natalie Shaw, a pediatric endocrinologist at the NIEHS, is the first to explore the potential impact of environmental chemicals on the brain as a cause of early puberty.
“I do think [excess weight] plays a role, but in my practice, it’s not just those who are overweight or obese who are having early puberty,” Shaw noted, suggesting that environmental factors may also be at play.
Puberty that begins significantly early—before age 8 in girls or age 9 in boys—can result in a range of long-term health risks, including an increased likelihood of developing breast cancer, diabetes, and heart disease.
Additionally, early puberty can lead to shorter adult stature in both girls and boys.
A recent Harvard T.H. Chan School of Public Health study found that 15.5% of girls now experience their first period before the age of 11, and 1.4% begin menstruating before age 9, raising alarms about the trend.
While previous studies have examined obesity, diet, and exposure to hormone-disrupting substances like phthalates, Shaw’s team decided to focus on a different approach.
Searching for environmental compounds that might affect brain function, they combed through a library of 10,000 substances, ultimately identifying musk ambrette as a likely contributor.
Musk ambrette, a synthetic fragrance ingredient, is widely used in inexpensive or counterfeit perfumes, soaps, and other scented products.
The study, published in Endocrinology, found that the compound could bind to receptors in the hypothalamus, the part of the brain that regulates hormone release, and trigger the production of gonadotropin-releasing hormone (GnRH), which is crucial for the start of puberty.
Testing the compound on human hypothalamic cells and zebra fish larvae, the researchers observed that musk ambrette sparked GnRH production in both cases, suggesting a possible link between the compound and the early onset of puberty.
However, Shaw cautioned that the findings are still preliminary.
“This is just a first step,” she said, adding that further research will investigate the effects of musk ambrette on mammals and its presence in human blood.
As the research continues, Shaw advised parents to be cautious about products their children are exposed to, particularly those with synthetic fragrances.
“Parents should check ingredient lists for musk ambrette on any cosmetics, fragrances, and household products,” Shaw suggested, though she emphasized that more studies are needed before drawing definitive conclusions.
Experts have responded positively to the study, though they stress that it is still too early to change public health policy. Dr Apisadaporn Thambundit, a pediatric endocrinologist at UCLA, acknowledged the importance of the research but warned that it’s not yet strong enough to recommend immediate changes to consumer behaviour.
She was surprised that phthalates, previously linked to early puberty, were not a focus in this study.
Jasmine McDonald, an associate professor of epidemiology at Columbia University Mailman School of Public Health, praised the study’s approach.
“The fact that the researchers started with a biological mechanism and then looked for a compound is a major strength,” McDonald said, though she cautioned that more research is needed before considering restrictions on musk ambrette.
She did, however, suggest that families might want to reduce their use of heavily scented products, saying, “If you need a lotion, it can be scent-free. In the shower, you can avoid scented body washes and shampoos.”
As research into the environmental causes of early puberty advances, the findings offer hope that scientists may soon be able to pinpoint the factors driving this alarming trend.
