Emotions and Cardiac Health
A commuter becomes enraged whenever he encounters bumper-to-bumper traffic. Eventually, he develops heart disease.
After decades of marriage, a devoted wife panics when her husband requests a divorce. An hour later, she suffers a heart attack.
These scenarios point to a question of longstanding interest to researchers who explore the association between mind and body - can the impact of negative emotions adversely affect the cardiovascular system?
Scientific evidence over the past 20 years suggests the answer may be "yes," said Laura Kubzansky, associate professor of society, human development, and health at HSPH. She delivered her talk, "Sick at Heart: The Pathophysiology of Negative Emotions," on July 17.
"People looked for a long time and tried to figure out whether stress, anxiety, or depression can influence heart disease," Kubzansky said.
She cited a study of more than 30,000 patients worldwide, published in The Lancet in 2004, indicating that the relative risk of acute myocardial infarction posed by emotional distress is about the same as that of cigarette smoking.
While acknowledging that negative emotions may increase heart-hazardous behaviors, such as smoking and inactivity, Kubzansky speculated that these emotions may also trigger vascular inflammation, excess hormonal levels, and other physiological responses that precipitate cardiac events.
Kubzansky summarized more than 50 prospective studies where individuals who presented significant levels of anger, anxiety, or depression faced 1.5 to three times the risk of coronary heart disease (CHD) in the three to 10 years that followed the studies, compared to those exhibiting low levels of the emotion. Anger, for example, was assessed with questions such as "Do you experience irritation when someone blocks your way?" and these studies also controlled for a wide range of other risk factors to rule out other causes of heart disease. Kubzansky also described a 1,500-patient study suggesting that extreme emotional events boost the risk of cardiac arrest within two hours of the precipitating event.
Scientists are now beginning to explore how positive attitudes can protect against heart disease, she noted. For example, four recent studies found that optimism measurably reduces the risk of heart disease. Moreover, in her own analysis of data representing initially disease-free U.S. men and women over a 20-year period, Kubzansky observed a significantly reduced risk of CHD among participants reporting high levels of positive emotions and a strong capacity to regulate emotions effectively.
She predicted that future research will explore biomarkers and genes associated with positive and negative emotions and will employ a wider range of study methods.
"Hopefully, as we get a handle on some of this," said Kubzansky, "we'll have better ways to prevent and mitigate the effects of negative emotions or increase the protective effects of positive ones."
—MD
Copyright, 2009, President and Fellows of Harvard College
