By Denise Mann
THURSDAY, Feb. 18, 2010 (Health.com) — Do you have a sunny outlook on life? If so, you have one more reason to be happy: You may be at less risk for heart disease.
People with a joyful, positive, and enthusiastic disposition—what psychologists call "positive affect"—are less likely than their gloomier peers to have a heart attack, a new study has found.
“This is the first study, to our knowledge, that has shown that clinically assessed positive emotions are protective of a first heart attack,” says the study's lead author, Karina W. Davidson, PhD, the director of the Center for Behavioral Cardiovascular Health at Columbia University Medical Center, in New York City.
Davidson and her colleagues followed 1,739 adults without previously diagnosed heart disease for 10 years. At the beginning of the study, the participants were asked how they typically respond to various situations, including stressful ones; researchers then used the videotaped interviews to rate how positive the people's emotions were on a scale of 1 to 5. Researchers also gauged the participants' risk of heart disease (by measuring cholesterol, blood pressure, and other risk factors) and their levels of depression, hostility, and anxiety.
During the follow-up period, there were 145 heart attacks and other cardiac events in the group. The study participants whose emotions were most positive (those who scored a "5" in the interview) had the lowest risk of heart attack and heart disease, the researchers found. For every 1-point decrease on the 5-point scale, a person's risk of experiencing a heart attack or other event increased by 22%, according to the study, which was published in the European Heart Journal.
This pattern held even after the researchers factored in how depressed (or not) the study participants were. The people who reported symptoms of depression but also had an upbeat outlook were still less likely to develop heart disease than people who were less positive. This was a significant finding, as previous studies have shown that depression is associated with a greater risk of heart disease.
“This new study adds to a growing body of research that documents the health-enhancing effects of positive affect [and] emotion,” says Redford B. Williams, MD, the head of behavioral medicine at Duke University Medical Center, in Durham, N.C. In their ability to promote heart health, he adds, "I believe positive emotions rank right up there with weight loss, exercise, and quitting smoking."
Experts don't fully understand how a positive outlook protects our hearts, but Davidson and her colleagues suggest that it may have beneficial effects on heart rate, blood pressure, and the stress hormone cortisol, which is involved in inflammation and can increase heart attack risk. Cheerful people may also sleep better, or may be more successful at quitting smoking than their less joyous counterparts, the researchers note.
Next page: You can learn to be more positive
If you tend to be a bit on the glum side, don't despair. Although positive affect is partly a matter of temperament, people can learn to be more positive.
Kim R. Lebowitz, PhD, the director of the Bluhm Cardiovascular Institute at Northwestern Memorial Hospital, in Chicago, is an advocate of positive psychology, a relatively new school of psychology that focuses on the benefits of positive traits (such as happiness, faith, optimism, and humor) rather than the harm caused by negative traits (such as anger, depression, anxiety, and hostility).
Lebowitz recommends that heart patients spend at least 30 minutes a day doing something they enjoy, or simply relaxing. “Currently, we encourage our cardiac surgery patients to increase pleasurable activities, engage in hobbies, and remain connected with close friends and family,” she says. “Our hope is that this will ward off depression, but perhaps the link is that these behaviors are increasing positive affect.”
Still, she says, “it's premature to know whether increasing positive affect has any impact on cardiovascular functioning.”
Davidson agrees that carving out time for yourself might make your emotions more positive. “Adding daily activities to one's life, most days of the week, that are pleasurable or enjoyable is one way to be happy,” she says. “Most of us let these things slip out of our schedule as we get busy or stressed."
Finding a treatment program that will turn a person's attitude from negative to positive "may be tough," says Bertram Pitt, MD, a professor emeritus of medicine at the University of Michigan, in Ann Arbor, who co-wrote an editorial that accompanies the new study. But that doesn't mean it's not worth trying, he says.
“The current approaches aren’t working, and you can’t lose by being happy,” says Dr. Pitt. “A lot of recent studies show that antidepressants increase mortality in people with heart failure, so we need other approaches. Maybe there are interventions to improve positive affect and decrease heart disease risk.”
The study did have some limitations. The researchers only measured heart health at the beginning of the study, and the heart-disease risk factors of some participants may have changed significantly in the following decade, potentially skewing the results. Emotions were likewise measured at the start, so the study didn't take into account subsequent changes in affect. Finally, because the study wasn't controlled, unknown factors may have influenced both positive affect and heart disease, making the association between the two appear stronger than it is.
The next step, Davidson says, is to conduct a controlled trial to see if interventions aimed at making people happier successfully stave off heart attacks. She and her colleagues are now recruiting patients for a study that will attempt to answer this question.