Neighborhood racial and economic privilege and timing of pubertal onset in girls

Black and Hispanic girls experience puberty earlier than girls of other racial and ethnic backgrounds, putting them at higher risk of adverse health outcomes throughout their lives.

Julia Acker, a doctoral student at UC Berkeley School of Public Health, collaborated with a team of researchers at Kaiser Permanente Northern California, to determine whether differences in racial and economic privilege at the neighborhood level may contribute to these disparities. They posited that inequitable neighborhood environments shaped by structural racism may confer different levels of exposure to stress, obesity, endocrine disruptors, and other factors that increase a girl’s risk of early puberty.

Their research drew on a multiethnic cohort of more than 46,000 girls at Kaiser Permanente Northern California who received care at Kaiser Permanente Northern California from birth to mid-adolescence.

Kaiser records revealed the ages of the girls at the onset of pubic hair (pubarche) and onset of breast development (thelarche). Investigators measured the level of racial and economic privilege of each participant’s neighborhood at birth. 

The study, published in mid-February 2023 in Journal of Adolescent Health, noted preliminary evidence that inequitable neighborhood conditions do influence timing of puberty. This student project used data from a larger parent study at Kaiser Permanente Northern California, Division of Research and was supported by senior authors Julianna Deardorff and Ai Kubo (study PI).

“Our study suggests that neighborhood racial and economic privilege, as measured by ICE, may contribute to girls’ pubertal timing and racial/ethnic disparities therein,” the authors wrote. “Compared to girls born into neighborhoods of concentrated privilege, girls born into neighborhoods of concentrated disadvantage were significantly more likely to experience pubarche and thelarche at earlier ages,” independent of their individual racial/ethnic identity or socioeconomic status. 

Early puberty is associated with adverse health outcomes over the course of life, including psychopathology in adolescence and cancer and cardiovascular disease in adulthood.