Early Puberty, Obesity, and Endocrine Disruption

Puberty is coming earlier for girls today, obesity in children is rising, and endocrine disruption seems to be playing a role in both of these phenomena. What’s more, exposure to endocrine disruptors follows a pattern of health disparities. This means that these environmental hazards may have the greatest effects on populations that already suffer disadvantages in health.

These are tricky issues to understand, and even trickier to address.

Early Puberty

In JAMA Network Open recently, Zifan Wang and colleagues documented the time of first menstruation for girls born between 1950 and 2005 in the U.S. In a cohort of 71,341 individuals, they found:

“As birth year increased, mean age at menarche decreased and time to regularity increased. The trends were stronger among racial and ethnic minority groups and individuals of low self-rated socioeconomic status. These trends may contribute to the increase in adverse health outcomes and disparities in the US.”

In a companion editorial, Lauren Houghton noted that the rise of obesity might contribute to this trend, but that other factors are undoubtedly contributing. But she also pointed to environmental toxins, including endocrine-disrupting chemicals. Many pieces are moving in this puzzle.

Exposure to endocrine-disrupting chemicals and microplastics have been implicated as potential risk factors for obesity. But of course, the definitive establishment of causality and quantification of their relative importance to other sources of obesity risk are difficult.

Adding to the concern about the cardiometabolic issues that microplastics create is recent data in the New England Journal of Medicine. Raffaele Marfella and colleagues found that microplastic and nanoplastic particles could be found in carotid artery plaque. Furthermore, the presence of those particles predicted nearly five times more risk for strokes, heart attacks, and deaths in their study over 34 months of follow-up.

Urgent Questions

We are accustomed to thinking about obesity and endocrine diseases in a rather simplistic, behavioral framework. Whatever the question, diet and exercise must be the answer. Early puberty? Obesity must be the problem and we know how to prevent that – or so we think.

But in truth, the intersection of early puberty, obesity, and endocrine disruption is not so simple. Jumping to conclusions is not wise because many potentially confounding factors are in play. However, ignorance is not bliss. This confluence of risk raises urgent questions. Strong doses of curiosity and objectivity are necessary to chase down some solid answers.

Click here for the study on microplastic particles in cardiovascular disease and here for further reporting on it. For the study of early onset of menstruation, click here and then here for the editorial that goes with it. For further reporting, click here and here. Finally, for new research insight on the relationship between prenatal exposures to endocrine-disrupting chemicals and metabolic health in children, click here and here.

Girl in Blue, painting by Amedeo Modigliani / WikiArt

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June 7, 2024