THURSDAY, Oct. 13, 2011 (HealthDay News) -- The stress associated with racial discrimination may take a heavy toll on the body, researchers say.
The finding could help explain why certain racial groups tend to have more heart disease, diabetes and other age-related conditions, according to a study published in the International Journal of Behavioral Medicine.
This study may be the first to find a possible physiological explanation for racial disparities in health, said Dr. Jennifer H. Mieres, a cardiologist and chief diversity and inclusion officer at North Shore-LIJ Health System in Manhasset, N.Y. Mieres was not involved with the study.
Psychological stress has long been linked to heart disease, cancer and other ailments. And racial discrimination is associated with higher blood pressure, obesity and even early death.
But what is the physiological mechanism at play here?
Small studies have suggested that psychological stressors may trigger oxidative stress, which "is a precursor to many, many illnesses like diabetes, cancer, heart disease and aging itself, it seems," said study lead author Sarah L. Szanton.
Healthy bodies maintain a balance between so-called free radicals, which can damage cells, and antioxidants, which are necessary for the body to repair itself from various insults and injuries.
But various factors, including behaviors such as smoking or eating fried food, will tip the seesaw in the wrong direction, resulting in more free radicals and, therefore, more oxidative stress, which wreaks havoc on the cellular functions that keep us alive.
To test whether racial discrimination was linked with oxidative stress, Szanton and her colleagues evaluated information on 629 adults -- blacks and whites -- who were enrolled in a U.S. National Institute on Aging study. They ranged from 30 to 64 years old and represented different income levels.
The participants had been asked about racial discrimination, and the researchers paired their answers with the results of blood tests that measured degradation of red blood cells, an indicator of oxidative stress.
More blacks reported racial discrimination than whites, and blacks who experienced more racial discrimination than their peers had more oxidative stress. Among whites, discrimination was not tied to oxidative stress.
This preliminary study only looked at overt discrimination, and additional research is needed to confirm the results. Future research might want to focus also on institutional discrimination, such as neighborhood and school segregation, said Szanton, an assistant professor at the Johns Hopkins University School of Nursing in Baltimore.
Mieres suggested that clinicians might want to incorporate more information on day-to-day stressors their patients face into treatment decisions.
"That might factor into making determinations for treating borderline blood pressure or diabetes," she said.
The U.S. Centers for Disease Control and Prevention has more on health disparities.