In a momentous 1992 paper, Arline Geronimus, ScD, now a professor of health behavior and health education at the University of Michigan–Ann Arbor, attempted to explain statistical differences in maternal age and birth outcomes between Black and white women. At the time, her argument—that systemic socioeconomic adversity can tax the body and mind to the point of premature deterioration—was dismissed. Now, in the wake of cultural conversations about white privilege and police brutality, that theory is widely accepted, according to NPR. Not only is racism emotionally painful, the experience may also be physically injurious.

Geronimus coined the term “weathering”—which may evoke the image of a rock being eroded by wind and water—to describe the negative effects of chronic discrimination. Her work sheds light on stark racial disparities in fertility, neonatal mortality and maternal mortality—disparities that cannot be explained by poverty, Medical News Today reports.

For example, African-American women, who are most likely to have a successful pregnancy in their late teens, reach their reproductive prime at a younger age than white women, who are most likely to have a successful pregnancy between ages 20 and 30. Furthermore, African-American women are 243% more likely to die during or shortly after childbirth compared with white women. (In fact, Geronimus first became interested in the intersection between health and environmental stress when she worked at a school for pregnant teenagers in New Jersey, NPR reveals.)

From a scientific standpoint, weathering makes more than a little sense. In response to stress, the brain releases neurotransmitters and hormones, such as cortisol. In excessive amounts, these hormones can inflict damage, which in turn may accelerate the aging process and increase mortality risk. (Greater stress equals higher hormone levels equals poorer physical health equals lower life expectancy.)

In an interview with NPR, Geronimus compared weathering to the party game Jenga.

“They pull out one piece at a time and another piece and another piece, until you sort of collapse,” she explained. “I thought that Jenga metaphor was very apt because you start losing pieces of your health and well-being, but you still try to go on as long as you can.”

This essential concept is encapsulated in the term “allostatic load,” which refers to the cumulative physiological toll exacted by repeated or prolonged exposure to stress. In a 2006 study, Geronimus and colleagues found that Black adults scored higher on measures of allostatic load than white adults. What’s more, they were more likely than their white counterparts to exhibit a high score at any age.

The scientists also observed that previous research suggests that higher allostatic load correlates with “older age, cognitive decline, increased mortality, lower socioeconomic status and unsupportive childhood and adult relationships.” One population in particular seemed to experience these ill effects: adult Black females.

“Black women [between ages 35 and 64] suffer the highest probability of having a high allostatic load score whether compared with Black men or with white men or women,” Geronimus and colleagues noted.

More recently, researchers found Black adults likelier to be biologically older than their chronological age than their white peers. These results explain, at least in part, the phenomenon that first piqued Geronimus’s interest in the health risks posed by racism: that fertility in African-American females apparently peaks in their teens rather than their 20s because these women age faster on a molecular level than white women.

For more on how racism can negatively affect the reproductive health of Black women, read “Black Women and Infants Face Worse Birth Outcomes” and “Does Racism Play a Role in Black Women Delivering Premature Babies?” And for more on the physiological toxicity of stress, read “Stress May Awaken Dormant Cancer Cells.”