People who previously experienced discrimination –- especially optimistic and trusting people -- suffer larger jumps in blood pressure when performing a stressful task such as talking about a situation that made them angry, according to a new study.
The results were similar for African American and white participants in the study, although blacks who had experienced discrimination had a larger surge in blood pressure during the stressful task. This may help explain why blacks have higher rates of cardiovascular diseases such as heart attacks, hypertension and strokes, said lead investigator Laura Smart Richman, an assistant research professor in Duke University’s Department of Psychology and Neuroscience.
“These results are consistent with discrimination being a chronic stressor that is related to acute stress responses, particularly for blacks,” Richman said. “It also may help to explain why people who experience more discrimination in their lives tend to have worse health outcomes.
“It’s being understood more and more that discrimination may be an important contributor to racial health disparities,” said Richman, one of a growing number of researchers bridging the fields of social psychology and health psychology to better understand the mind-body connection.
The findings are in the November issue of Health Psychology, a publication of the American Psychological Association. The study was funded by a grant from the National Heart, Lung and Blood Institute.
The study’s co-authors are Gary G. Bennett of the Harvard School of Public Health, Jolynn Pek of the University of North Carolina at Chapel Hill, and Ilene Siegler and Redford B. Williams of Duke.
Discrimination and stress
In order to determine what long-term effects, if any, past discrimination might have on cardiovascular reactions to new, stressful experiences, Richman’s team had participants report on the frequency of their past exposure to discrimination.
Then, participants were exposed to a new, unrelated stressor by asking them to recall a time when they were angry. Heart rate and blood pressure were monitored before, during and after the recall task. Researchers also calculated the time it took heart rate and blood pressure to return to normal, resting rates.
Participants were Durham, N.C., residents, and included blacks, whites, men and women of high and low socioeconomic status in roughly equal proportions. The sample included 71 whites (39 men, 32 women) and 94 blacks (52 men, 42 women.)
The data showed similar cardiovascular reactions to stress for all participants in the study, regardless of race, gender or socioeconomic status, but that the blood pressure of blacks went up more than whites. “Their blood pressure rose more during the stressor and took longer to get back to their pre-stress baseline,” the study said.
The study also found that stress reactions were larger, and recovery times longer, in whites and blacks who had experienced high levels of past discrimination and had either high optimism or low cynicism. A high level of cynicism, on the other hand, was seen to be protective.
Previous research has demonstrated the benefits of optimism to overall health –- “optimism has long been found to serve as a buffer against the negative effects of stressful events and to generally be protective for health,” Richman said -- but this study found that optimism may not be protective of cardiovascular health when combined with a previous history of discrimination.
“It could be the result of defying expectations,” Richman said. “Optimistic people expect others to treat them well, and when this is not the case it results in more distress and larger blood-pressure surges when recalling a situation that made them angry.”
Researchers believe this finding reflects how personality and individual views about the world shape our expectations.
“Those who are highly cynical and thus already have negative, untrusting attitudes and beliefs may expect life to be unfair to some extent. Thus, when discriminatory events do occur, it may not be as stressful an experience as for those who were relatively less cynical,” the study said.
Most previous research on cardiovascular outcomes has sampled only white males of middle to high socioeconomic status, Richman said.
“That’s what’s unique. It was intentionally designed to have blacks and whites of both low and high socioeconomic status,” Richman said. “Usually you don’t see samples like that.”
Richman said the study reinforces the view that discrimination has real effects on health.
“Societal discrimination can affect differences in housing and education as well as differences in treatment in the health care system and other things,” she said. “But taking it on a more micro level, we are seeing that everyday chronic experiences can ultimately have a negative effect on cardiovascular outcomes because of the acute blood-pressure surges during stress.”
Richman cautioned that though the findings suggest that blacks who are more trusting and optimistic may be more adversely affected by experiences of discrimination, “these findings do not imply that intervention strategies should be designed to reduce blacks’ optimism or to increase their cynicism.”
Instead, there is a need to better understand the underlying mechanisms that explain how discrimination has an impact on health outcomes, she said.
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