New research has shown that negative emotional states including anger and anxiety leading to stress and depression not only affect the functioning of the heart, but also increase the risk for heart disease.
Heart attacks and stroke occur when vessels supplying blood to the heart and brain become damaged, a process called atherosclerosis. It is thought that stress increases the risk for atherosclerosis and cardiovascular disease by raising the levels of pro-inflammatory chemicals in the body.
Researchers at the University of Pittsburgh have now investigated the underlying neural circuitry involved in this process.
"Drawing upon the observation that many of the same brain areas involved in emotion are also involved in sensing and regulating levels of inflammation in the body, we hypothesised that brain activity linked to negative emotions - specifically efforts to regulate negative emotions - would relate to physical signs of risk for heart disease," explained Dr. Peter Gianaros, Associate Professor at the University of Pittsburgh and first author on the study.
The study involved 157 healthy adult volunteers who were asked to regulate their emotional reactions to unpleasant pictures while their brain activity was measured with functional imaging. The researchers also scanned their arteries for signs of atherosclerosis to assess heart disease risk and measured levels of inflammation in the bloodstream, a major physiological risk factor for atherosclerosis and premature death by heart disease.
They found that individuals who show greater brain activation when regulating their negative emotions also exhibit elevated blood levels of interleukin-6, one of the body's pro-inflammatory cytokines, and increased thickness of the carotid artery wall, a marker of atherosclerosis.
The inflammation levels accounted for the link between signs of atherosclerosis and brain activity patterns seen during emotion regulation. Importantly, the findings were significant even after controlling for a number of different factors, like age, gender, smoking, and other conventional heart disease risk factors.
"These new findings agree with the popular belief that emotions are connected to heart health," said Dr Gianaros. "We think that the mechanistic basis for this connection may lie in the functioning of brain regions important for regulating both emotion and inflammation."
These findings may have implications for brain-based prevention and intervention efforts to improve heart health and protect against heart disease."
The findings are reported in the current issue of Biological Psychiatry.
