Ethnic discrimination and health: Direct link found

"Many people think that ethnic discrimination only has psychological impacts," said the study's lead author Zaneta Thayer, PhD, assistant professor of Anthropology at CU Denver, a major center of timely, topical and relevant research. "But in fact, ethnic discrimination can impact physical health as well, possibly through changes in stress physiology functioning."

Thayer's research, published this week in the journal `Social Science & Medicine,' may be the first to draw a direct connection between ethnic discrimination and impacts on stress hormones in pregnant women and infants.

The study's second author was Anthropology Prof. Christopher Kuzawa of Northwestern University.

The research was done in Auckland, New Zealand where Thayer examined 64 pregnant women of various 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 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.

One third of the women reported being discriminated against which was associated with higher levels of evening cortisol.

Notably, this association remained after controlling for material deprivation, suggesting that the impacts of discrimination experience on maternal cortisol are independent of socioeconomic status.

"To our knowledge this is the first study to report an association between maternal ethnic discrimination and maternal stress physiology in pregnancy or with stress in infancy," Thayer said.

For Thayer, who studies how social inequalities create health inequalities, the findings indicate that discrimination may produce far reaching physiological changes.

"The finding that offspring of women who experienced ethnic 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," she said.

In light of this, Thayer said, reducing ethnic discrimination may not only improve the health of those directly impacted but also that of future generations.