Chronic stress in Black men, measured through hair cortisol, linked to neighborhood violence

For 25 years, Curtis Eskridge has been cutting hair in his South Shore barbershop, Cut it Out Curt. Now the trimmings on his shop floor are helping researchers learn more about chronic stress in Black men living in areas with high rates of violent crime.

In a new study, UIC researchers collected and examined hair samples at Eskridge’s barbershop and others in four Chicago neighborhoods. They found that Black men who live in neighborhoods with high rates of violent crime have elevated levels of cortisol in their hair. Cortisol is a measure of chronic stress.

Long-term exposure to stress can increase the risk of chronic conditions, said Sage Kim, professor in health policy and administration in the UIC School of Public Health and lead author of the new research.

Kim’s team has seen geographic clusters of people with lung cancer in predominantly Black communities on the West and South sides of Chicago, even though Black people smoke less frequently and start smoking later in life than white people.

“Something about place contributes to increased risk of lung cancer,” Kim said. In many cities, including Chicago, a history of racial residential segregation has created different neighborhood conditions for Black and white residents.

One differing condition would be exposure to social stress, Kim said. She and her team set out to investigate how these factors were linked in Chicago. “Would exposure to social stress increase the risk of developing lung cancer?” she said.

Indicator of stress

When the body experiences stress, the adrenal glands release cortisol, which can be measured in saliva, blood and hair. The hair shaft can store months’ worth of cortisol and, therefore, can capture chronic stress.

Kim’s team partnered with four barbershops on Chicago’s South and West sides to recruit study participants and collect hair samples. They analyzed hair from 160 Black male Chicago residents who were current or former smokers and at least 45 years old.

The researchers quantified neighborhood violence using community homicide rates. They also asked study participants about the neighborhood they lived in and their self-reported exposure to violence, fear of crime, perceived stress and experience with PTSD and depression.

The study, published in Psychoneuroendocrinology, found that the concentration of cortisol in hair from residents of community areas with higher homicide rates was 1.8 times higher than that in hair from residents in community areas with lower homicide rates.

“The neuroendocrine system that regulates the stress response becomes dysregulated” when individuals experience chronic stress, Kim said. This induces pro-inflammatory reactions that can contribute to the development of conditions like obesity, heart disease and cancer, she said.

Community partnerships and systemic solutions

Kim’s team created a website, the Lung Health Equity Project, as part of their initiative investigating cancer health disparities in Chicago. Researchers established relationships with barbershops in the city and trained partner barbers as “citizen scientists” to recruit participants and collect data.

“Our barbers are committed to bridging the community and research,” Kim said of the community partners.

Eskridge, owner of Cut it Out Curt, is one such partner.

“I think because they come in here for me to help them look good, that makes them feel good. That’s my motto. It can’t just stand for the hair,” Eskridge said of patrons at his long-standing business.

The researchers’ mission of bridging gaps in health outcomes and keeping his community healthy resonates with him. “If you go to the doctor on a regular basis, you can find out illnesses that are preventable,” he said.

When Kim and her colleagues shared study results with them, the partners suggested they build a website to disseminate the findings and connect readers to community resources. And while reducing individual stress is important, Kim said, interventions are needed at the community and policy levels, too. Massages and mindfulness trainings can only go so far in addressing the problem, she said. Chronic problems require more systemic solutions.

Her goal is to build a referral system between community-based organizations and federally qualified health centers in Chicago to improve cancer screening and address social needs such as housing, food and transportation.

“Our community organizations encounter a lot of people who could be eligible for cancer screening, but they don’t have mechanisms to make a referral to health clinics to do the health screening,” Kim said of organizations like shelters and food banks.

“UIC is a Minority-Serving Institution. We’re embedded in Chicago,” Kim said. “It’s important that UIC is doing this kind of research. Our work actually reflects the needs of the community,” she said.