A study published in JAMA Network looked at the average age of first menstruation of more than 71 thousand women. When comparing women born in 1950 to 1969… and those born from 2000 to 2005… It found the average age decreased from 12.5 to 11.9 years old.

Susan Pinney, PhD, Epidemiologist at University of Cincinnati College of Medicine says, “It’s a time where certain parameters are set leading into later life.”

Early puberty is linked to an increased risk of health issues such as obesity, diabetes, cardiovascular disease, and breast cancer.

Professor Pinney says, “That’s why we worry about environmental exposures during puberty that seem to perturb the normal pattern of development.”

Researchers with NIH say the rapid pace of these changes’ points to environmental factors. They studied more than 10 thousand compounds found in drugs and chemicals. Of those, one in particular stood out.

Musk Ambrette is a fragrance molecule found in some soaps, detergents, perfumes, and lotions. The study found this chemical can impact the area of the brain that releases hormones to trigger puberty. Professor Pinney says delayed puberty is also a problem brought on by the same environmental factors.

Professor Pinney says, “We discovered that various aspects of puberty were delayed in girls that had higher levels of PFOA, one of the PFAS and also a couple other of the pfas types of chemicals.”

The environmental working group says watch for the word “fragrance” on product labels, which could include musk ambrette and dozens of other unnamed chemicals. Instead, choose products that list all of the ingredients, so you know what’s in it.