In the first ever study to look at intergenerational effects of discrimination on stress hormones, Zaneta Thayer, Assistant Professor of Anthropology, shows that women who experience racial discrimination while pregnant suffer significant health impacts that are passed on to their infants. "Many people think that ethnic discrimination only has psychological impacts," says Thayer, "But in fact, ethnic discrimination can impact physical health as well, possibly through changes in stress physiology functioning."

Thayer's research, co-authored with Anthropology Professor Christopher Kuzawa of Northwestern University, published in Social Science and Medicine, and titled "Ethnic Discrimination Predicts Poor Self-rated Health and Cortisol in Pregnancy: Insights from New Zealand," looks at the relationship between a woman's experience of racial discrimination and her stress hormones in pregnancy as well as her offspring's stress hormones in infancy. The research found that both maternal and offspring stress hormones were associated with maternal experience of racism.

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 harassed, verbally or physically attacked, insulted, or ignored because of 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, and these women had higher levels of evening

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 health of her child," Thayer says. "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 physiology in infancy." In light of this, Thayer says, reducing ethnic discrimination may not only improve the health of those directly impacted but also that of future generations.

Thayer has also published work on racial disparities in birth outcomes in the United States. Her research broke new ground by providing evidence that, contrary to previous theories, Vitamin D is unlikely to play a role in differences in preterm birth and low birth weight between African-Americans and whites. She says, "For years there has been this hypothesis that African-Americans have worse birth outcomes because they have more melanin in their skin which reflects the sun and therefore lowers levels of Vitamin D. But in examining the relationship between ultraviolet exposure and birth outcomes nationwide, there was no evidence to support this."

The so-called ultraviolet light or UVD theory holds that racial differences in health outcomes between blacks and whites are associated with the ability to synthesize Vitamin D from ultraviolet light. African-Americans, who have high concentrations of melanin, are less able to absorb Vitamin D from the sun leading some to believe that this contributes to higher rates of negative birth outcomes. According to the UVD hypothesis, the difference in birth outcomes between whites and blacks should be lower among women in areas with more sunshine or UV radiation. In fact, according to Thayer's work, there was an increase in disparities in those areas. A lack of Vitamin D has been linked to increased risk of pregnancy complications, bone disorders, cardiovascular disease, diabetes and some cancers. At the same time, differences in socioeconomic status and racial discrimination have also been linked to low birth weights, risk of depression and other ailments. "Given the UV hypothesis, we would expect that women who live in the South would have better birth outcomes than those living in the North," Thayer said. "However, the present analysis suggests the exact opposite, with both absolute rates as well as racial disparities in adverse birth outcomes being greatest in southern states."

Thayer collected data on UV exposure in 48 states or territories, using information compiled from the National Oceanic and Atmospheric Administration (NOAA) National Weather Service website. She also used birth outcome data came from the National Centers for Disease Control and Prevention, focusing specifically on incidences of low birth weight and preterm births. Published in the American Journal of Epidemiology, the study found that states with the highest income inequalities had higher disparities in birth outcomes across the UV spectrum. The racial disparity in low birth weight was greatest among women living in areas with high UV exposure and greater income inequality. The disparity in preterm births was also highest in areas with increased UV exposure and income inequality.

"The results suggest that the environment is a stronger contributor to adverse birth outcomes than genes, since there is a significant environmental gradient in adverse birth outcomes across states" Thayer said. "That said, it seems unlikely that disparities in birth outcomes in the US are primarily shaped by differences in UV-induced Vitamin D status." Thayer thinks it might be time to stop looking at genes as the primary cause of racial differences. She says, "We need to focus on addressing structural inequalities in society like poverty and discrimination that shape individual experience and health."

Thayer is continuing her research into the intergenerational effects of stress while teaching at CU Denver. Last summer she returned to New Zealand to continue studying an ethnically and socioeconomically diverse sample of women who were pregnant when the research began. Thayer has conducted epigenetic analysis of their children's DNA. What this allows her to see is whether maternal stress experience is associated with changes in the way offspring genes are turned on and off.

Being able to conduct her research while also teaching was one of the reasons Thayer chose to join the Anthropology Department at CU Denver. "I thought I could get my work done here in a relaxed and friendly environment," she says. "The opportunity here gave me the best of both worlds—I wanted to be able to teach and do research."

Thayer earned her bachelor's degrees in biology and anthropology at Dartmouth College and advanced degrees—master's and doctoral in anthropology—at Northwestern University. She finished her doctoral degree in anthropology in 2013 with impeccable academic credentials, and was considering various options when she saw a faculty position posted in the Department of Anthropology at the University of Colorado Denver. Thayer had been offered a research position at a medical school, but she also wanted to teach. She didn't know much about CU Denver, but enjoyed her interview and says, "I liked the people who would be my colleagues. They seemed very supportive. CU Denver struck me as a place that's transitioning toward a greater emphasis on research while also maintaining a strong commitment to teaching."

Thayer has taken advantage of the consolidated system at CU Denver by collaborating with the Division of American Indian and Alaska Native Programs in the Nighthorse Campbell Native Health Building on the Anschutz Medical Campus. Through that resource, she learned about and secured a two-year fellowship that will allow her to develop a domestic research project—similar to her New Zealand study—among an American Indian population. As part of her fellowship she has conducted a study, currently in review, that evaluates the relationship between early life stress and adult health among a sample of American Indians from the Northern Plains. She and co-authors found that individuals who experienced early life stress were at increased risk for developing post-traumatic stress disorder and poor health in adulthood. Notably, these effects were independent of trauma exposure and substance abuse in adulthood. These results suggest that in order to improve adult health in these communities there must be more attention paid to support women and families in order to improve child wellbeing.

Coming from a Mexican and American Indian (Lakota) heritage, and being the first member of her family to earn advanced university degrees (her older sister was the first in the family to earn a bachelor's degree), Thayer has become a fan of the university's exceptional diversity. She says, "I paid my way through college, so I have a lot of respect for the students at CU Denver who are also having to do that." Having grown up on a farm outside Sacramento, California, Thayer says she's also glad to be living in the West again. Overall, Thayer says she is pleased that she brought her passion and expertise to CU Denver, where she is able to grow as both a teacher and researcher among purposeful students and colleagues from many disciplines who who are standouts in their fields.

Excerpted from previous pieces, you can find more about Thayer here. Special thanks to David Kelly.