Univeristy of Florida: It’s no secret that discrimination is stressful for those who experience it, but turns out the issue is more than skin deep—these stressors can interact with our genetics to negatively impact our health, a new University of Florida study shows. Study researchers developed a novel measure of unfair treatment to study the effects of discrimination on health, particularly with respect to racial disparities in complex diseases, which are illnesses resulting from both genetic and environmental factors. They used the measure to investigate hypertension, which is more prevalent in African-Americans, and found that discrimination interacts with certain genetic variants to alter blood pressure.
The researchers also measured vicarious unfair treatment, or
experiences of discrimination by close friends and family to the study
participant. They were surprised to discover that study participants
were more significantly impacted by unfair treatment of close family
members or friends than when they experienced discrimination firsthand,
said Connie Mulligan, a professor with appointments at UF’s department
of anthropology and Genetics Institute.
“We’ve been missing a huge factor in explaining racial disparities in disease,” said Mulligan, co-author of the new study online today
in PLOS ONE. “Our finding of an interaction between genetics and
environment could explain why it’s been so hard to identify all the risk
factors for complex diseases, particularly those that have racial
disparities. You have to look at genetics and environment in the same
study if you’re investigating complex diseases like hypertension,
certain kinds of cancer and psychological disorders.”
In a first of its kind study, UF researchers combined anthropological
analysis, including in-depth, ethnographic interviews with 157
African-Americans, with measurements of 30,000 genetic variants and
measures of genetic ancestry.
Mulligan and colleagues identified eight significant genetic variants
in five genes that were previously associated with cardiovascular
disease. When they added sociocultural data collected by study co-author
Lance Gravlee, an associate professor of anthropology at UF, and
community partners in Tallahassee, Florida, and their novel measure of
vicarious unfair treatment, and tested for interactions between genetic
variants and unfair treatment, they were able to identify associations
with blood pressure and a new class of genes that previously had been
associated with psychosocial distress and mood disorders.
Study authors suggest genetic variants that predispose some people to
depression, anxiety or suicide might also make them more sensitive to
the effects of discrimination and lead to higher blood pressure. The
role of these genes with blood pressure regulation may only become
relevant when dealing with the effects of discrimination and could help
explain why it’s been so difficult to understand racial disparities in
disease, Mulligan said.
As for the finding that vicarious discrimination causes greater
stress, Mulligan said people may feel they have more control over things
experienced personally than acts of discrimination happening to people
close to them.
“People may also be reluctant to report personal experiences of
discrimination to avoid the stigma, and denial may itself be a coping
mechanism,” Mulligan said “It’s also likely effects of vicarious unfair
treatment may be even greater, since the study did not include events
that one hears through the news, such as an act of racial violence.”
Mulligan was inspired by the personal history of the study’s lead
author Jacklyn Quinlan, a former UF postdoctoral researcher, who tackled
the project after the loss of her Caribbean-American husband to a heart
She hopes the new study will broaden the way both the academic and medical fields approach disease.
“We’re quick to say that racial disparities in disease are due to
poverty or access to good healthcare. Or that there might be a genetic
basis. Our research suggests it’s even more complicated,” Mulligan said.
Other study co-authors were Qasimah Boston with Health Equality
Alliance of Tallahassee (HEAT) and the Florida Department of Children
and Families Substance Abuse and Mental Health Program, Christopher J.
Clukay with UF’s department of anthropology, Miaisha M. Mitchell with
HEAT and Greater Frenchtown Revitalization Council in Tallahassee, and
Laurel N. Pearson with Pennsylvania University’s department of