New research from the University of Colorado Denver shows that women who experience racial or ethnic discrimination while pregnant suffer significant health impacts that are passed on to their infants, adding to an expansive body of evidence documenting the very real consequences of toxic stress stemming from racism.
“Many people think that discrimination only has psychological impacts,” said Dr. Zaneta Thayer, PhD, the study’s lead author and an assistant professor of Anthropology at CU Denver. “But in fact, racial and ethnic discrimination can impact physical health as well, possibly through changes in stress physiology functioning.”
The research, published this week in the journal Social Science & Medicine, is believed to be the first to establish a direct connection between racial/ethnic discrimination and impacts on stress hormones in both pregnant women and their infants. However, the findings are just the latest in a line of research showing that experiences of discrimination can have lifelong adverse health effects.
Studies have shown, for instance, that the stress of racism is associated with weight gain and related disorders such as diabetes and heart disease among black women. And these effects start early: According to one a recent study, experiencing racism during youth triggers a pattern of psychological and physiological vulnerability to stress that, over time, leads to worse physical health, poorer overall wellbeing, and even less supportive social relationships.
In this latest study, Dr. Thayer and her colleague Dr. Christopher Kuzawa, of Northwestern University, examined 64 pregnant women of various racial and ethnic backgrounds. The women filled out questionnaires asking whether they had been being harassed, verbally or physically attacked, insulted, ignored or condescended to based on their race/ethnicity.
Researchers then collected saliva samples from the women in the morning and the evening to measure cortisol levels. Cortisol is a stress hormone which, if overproduced, can lead to a host of chronic ailments including cardiovascular disease and mental illness. Infant saliva was also analyzed along with birth outcome information such as weight, length, head circumference and length of gestation.
Discrimination linked to increased cortisol levels in mothers and infants
Overall, one-third of the women reported being discriminated against, with minority and immigrant women reporting significantly more experiences of discrimination than women of European descent. The results revealed a significant association between experiences of discrimination and physiological stress levels among both mothers and infants.
“Women reporting discrimination experience had worse self-rated health, higher evening cortisol and gave birth to infants with higher cortisol reactivity, all independent of ethnicity and material deprivation,” the researchers report. Notably, this association remained after controlling for material deprivation, suggesting that the impacts of discrimination experience on maternal cortisol are independent of socioeconomic status.
Dr. Thayer, who studies how social inequalities create health inequalities, says the results demonstrate that discrimination can produce far reaching physiological changes. “These findings suggest that discrimination experience can have biological impacts in pregnancy and across generations, potentially contributing to the ethnic gradient in health,” the researchers conclude.
In light of this, the authors say, reducing racial discrimination may not only improve the health of those directly impacted but also that of future generations.
“The finding that offspring of women who experienced racial discrimination had greater cortisol reactivity in early infancy adds to the growing evidence that a woman’s emotional, physical and mental well-being, during or around the time of pregnancy can influence the biology of her child,” said Dr. Thayer.