A groundbreaking study has shed light on a possible factor contributing to the trend of children reaching puberty at younger ages in recent decades. Researchers have found that a commonly used chemical called musk ambrette, known for adding scent to various products, may play a role in triggering the release of puberty-related hormones at an earlier stage than usual.

Published in the journal Endocrinology, this first-of-its-kind research explores the impact of environmental chemicals on the brain, potentially leading to early puberty. Dr. Natalie Shaw, a pediatric endocrinologist at the National Institute of Environmental Health Sciences and co-senior author of the study, stated in an interview with NBC News that it is too early to definitively conclude whether musk ambrette is a contributing factor, but precautionary measures can be taken by parents.

The study provides alarming statistics about the decline in the average age of puberty onset. From 1977 to 2013, the average starting age of puberty for girls decreased by approximately three months per decade. Furthermore, a 2012 study revealed that boys were entering puberty six months to two years earlier than previous research suggested. Another large-scale study published in May 2024 in JAMA found that girls are experiencing their first periods at a younger age, with a longer time span until periods become regular.

Previous theories attributing the early puberty trend to factors such as childhood obesity, inadequate nutrition, and exposure to phthalates (added to plastics) have not been conclusively proven. However, Dr. Shaw believes that the rapid change in puberty onset points to environmental influences.

Early puberty carries potential health risks, including an increased likelihood of breast, endometrial, and testicular cancers, diabetes, heart disease, obesity, and psychological issues. Exploring the effects of various compounds, the study focused on musk ambrette as a synthetic form of musk that can attach to brain receptors associated with puberty and stimulate the release of the hormone GnRH, affecting sexual maturation and the production of sex hormones like estrogen, testosterone, and progesterone.

Apart from musk ambrette, the researchers identified other chemicals, such as cholinergic agonists, that could potentially influence puberty. However, Dr. Shaw suggests that musk ambrette is of particular concern for children due to its presence in personal care products. Studies have also indicated that musk ambrette can accumulate in human tissues, as it has been detected in maternal blood, umbilical cord blood, and breast milk, raising further alarm about potential risks.

Musk ambrette is widely used as a fragrance in personal care and household products, as well as a flavoring food additive. Although the European Union has prohibited its use in cosmetics, and Canada has implemented restrictions, the United States still allows its inclusion in various products. Dr. Michael Hansen, a senior scientist at Consumer Reports, recommends reducing exposure to musk ambrette and related compounds like musk xylene and musk ketone, especially in personal care products that can be inhaled and easily reach the brain through mucous membranes.

While some experts caution against taking immediate action based solely on this research, both Dr. Shaw and Dr. Hansen agree that it is prudent to limit children's exposure to musk ambrette and its derivatives. Follow-up studies should investigate musk ambrette exposure in communities more susceptible to early puberty. In the meantime, it is advisable to scrutinize product ingredients and avoid those containing musk ambrette or listed under synthetic or natural fragrance or flavoring labels, particularly in cases where the scent is unnecessary.

As research continues to unveil potential contributors to early puberty, the focus remains on protecting children's health by taking proactive measures to reduce exposure to harmful substances.