October 17, 2011
Nursing researcher links oxidative stress to racial discrimination
Johns Hopkins University School of Nursing assistant professor Sarah Szanton, in collaboration with scientists from the National Institute on Aging and the University of California, San Francisco, has concluded that African-Americans who report more frequent racial discrimination have higher levels of oxidative stress in their bodies. Their study is published online in Springer’s International Journal of Behavioral Medicine. Oxidative stress is the process by which free radicals, or reactive oxygen species, damage cellular components including DNA, proteins and lipids.
“This is a preliminary report of an association between racial discrimination and oxidative stress. It is a first step to understanding whether there is a relationship between the two,” Szanton said. “Our findings suggest that there may be identifiable cellular pathways by which racial discrimination amplifies cardiovascular and other age-related disease risks.”
The consequences of racial discrimination may contribute to racial health disparities in conditions such as cardiovascular disease, diabetes and other age-associated diseases. This is according to analyses of data from the epidemiologic study Healthy Aging in Neighborhoods of Diversity across the Life Span, or HANDLS, conducted by the National Institute on Aging.
The psychological stress of racial discrimination is thought to be one of the factors that explain racial health disparities for conditions such as high blood pressure, obesity, cardiovascular problems, poor self-reported health and premature disease-related disability. There is some evidence that psychological stress increases oxidative stress.
Szanton and NIH investigators hypothesized that if oxidative stress is causally associated with a psychological stressor such as racial discrimination, then disparities in psychological stress might help explain some of these health disparities. To test their hypothesis, the authors looked, for the first time, at whether there was a link between reports of racial discrimination and red blood cell oxidative stress among 629 participants enrolled in HANDLS. Researchers measured oxidative stress by determining the level of degradation products in red blood cells and assessed racial discrimination by asking participants how much prejudice, or discrimination, they had experienced because of their race.
Overall, African-Americans reported more racial discrimination than whites and more oxidative stress originating from their red blood cells as measured by a novel marker. In addition, African-Americans who reported suffering from racial discrimination had higher levels of oxidative stress than those who had not experienced prejudice. Discrimination was not linked to levels of oxidative stress in whites.