Dwelling on stressful events can increase levels of inflammation in the body, according to a new study.
Researchers from Ohio University discovered that when study participants were asked to ruminate on a stressful incident, their levels of C-reactive protein, a marker of tissue inflammation, rose.
The study is the first to directly measure this effect in the body, according to Dr. Peggy Zoccola, an assistant professor of psychology.
“Much of the past work has looked at this in non-experimental designs,” she said. “Researchers have asked people to report their tendency to ruminate, and then looked to see if it connected to physiological issues. It’s been correlational for the most part.”
For this study, the research team recruited 34 healthy young women. Each was asked to give a speech about her candidacy for a job to two interviewers in white laboratory coats, who listened with stone-faced expressions, Zoccola said.
Half of the women were asked to contemplate their performance in the public speaking task, while the other half were asked to think about neutral images and activities, such as sailing ships or grocery store trips.
The researchers then drew blood samples, which showed that the levels of C-reactive protein were significantly higher in the subjects who were asked to dwell on the speech, Zoccola reported.
For these women, the levels of the inflammatory marker continued to rise for at least an hour after the speech. During the same time period, the marker returned to starting levels in the subjects who had been asked to focus on other thoughts, the researcher said.
The C-reactive protein is primarily produced by the liver as part of the immune system’s inflammatory response. It rises in response to traumas, injuries or infections in the body, Zoccola explained.
“More and more, chronic inflammation is being associated with various disorders and conditions,” Zoccola said. “The immune system plays an important role in various cardiovascular disorders, such as heart disease, as well as cancer, dementia and autoimmune diseases.”
Zoccola is lead author on the new study, which she will present Friday at the annual meeting of the American Psychosomatic Society in Miami, Fla.
Source: Ohio University