As the debate regarding how our mental and emotions impact our health, yet another study confirms the ancient truth—a merry heart creates good health.


In the field of psychology and health, numerous studies have established a direct link between depression, hostility, anxiety, worrying and heart disease.  Medical researchers are now evaluating the impact positive affect has on health, including risk factors for heart disease, diabetes and hypertension. 


Previous studies have found and inverse association between positive affect and death caused by strokes in hospitalized patients as well as diabetic patients, protective against major clinical events.


Positive affect refers to experiencing pleasurable emotions such as joy, happiness, excitement, enthusiasm and contentment. These feelings can be transient, but they are usually stable and consistent, especially during adulthood. Positive affect is largely independent of negative affect, so that someone who is generally a happy, contented person can also be occasionally anxious, angry or depressed.


A recent study conducted in Canada determined people who are usually happy, enthusiastic and content are less likely to develop heart disease than those who tend not to be happy.  The study published in the European Heart Journal, is the first to demonstrate a relationship between positive emotions and a decreased risk for developing heart disease.


During the course of a decade, Dr. Katrina Davidson, and her associates followed over 1,700 people (877 women and 862 men) who were participants in the 1995 Nova Scotia Health Survey.  The participants were assessed at the study’s launch by nurses for the risk of developing coronary artery (heart disease).  Their psychological state was also evaluated, for several known heart disease risk factors, including anxiety, depression, and hostility, as well as their level of expressive positive emotions.


Dr. Karina Davidson, noted that while it was an observational study, the findings suggest that appropriate intervention may help to prevent the development of heart disease by improving a person’s level of positive emotions. 


“We desperately need rigorous clinical trials in this area. If the trials support our findings, then these results will be incredibly important in describing specifically what clinicians and/or patients could do to improve health,” said Dr Davidson, who is the Herbert Irving Associate Professor of Medicine & Psychiatry and Director of the Center for Behavioral Cardiovascular Health at Columbia University Medical Center located in New York City.


The study took into account the participants, gender, age, negative emotions, heart disease risk factors, and found that over a decade increased positive affect predicted a decreased risk of developing heart disease by 22% per point on a five-point scale measuring levels of positive affect expression.


Dr.  Davidson said: “Participants with no positive affect were at a 22% higher risk of heart disease (heart attack or angina) than those with a little positive affect, who were themselves at 22% higher risk than those with moderate positive affect.


“We also found that if someone, who was usually positive, had some depressive symptoms at the time of the survey, this did not affect their overall lower risk of heart disease.


“As far as we know, this is the first prospective study to examine the relationship between clinically-assessed positive affect and heart disease.”


The researchers think there are several physiological pathways by which positive emotions might be responsible for providing prolonged protection from developing heart disease. They include sleeping patterns, heart rate regulation and smoking cessation. Also, the response to stress is much less damaging in people with positive emotional states.


“We have several possible explanations,” said Dr Davidson. “First, those with positive affect may have longer periods of rest or relaxation physiologically. Baroreflex and parasympathetic regulation may, therefore, by superior in these persons, compared to those with little positive affect. Second, those with positive affect may recover more quickly from stressors, and may not spend as much time ‘re-living’ them, which in turn seems to cause physiological damage. This is speculative, as we are just beginning to explore why positive emotions and happiness have positive health benefits.”


Dr. Davidson also noted that the most successful interventions for depression include increasing positive affect as well as decreasing negative affect, known as anhedonia. She also discussed how to take a few simple steps to increase their positive affect.


“Like the observational finding that moderate wine consumption is healthy (and enjoyable), at this point ordinary people can ensure they have some pleasurable activities in their daily lives,” she said. “Some people wait for their two weeks of vacation to have fun, and that would be analogous to binge drinking (moderation and consistency, not deprivation and binging, is what is needed). If you enjoy reading novels, but never get around to it, commit to getting 15 minutes or so of reading in. If walking or listening to music improves your mood, get those activities in your schedule. Essentially, spending some few minutes each day truly relaxed and enjoying yourself is certainly good for your mental health, and may improve your physical health as well (although this is, as yet, not confirmed).”


“Randomised controlled trials of interventions to increase positive affect in patients with cardiovascular disease are now underway and will help determine the effectiveness of increasing positive affect on cardiovascular outcome and will provide insight into the nature of the relationship between positive affect and cardiovascular disease,” they wrote.


“The ‘vicious cycle’ linking cardiovascular disease to major depression and depression to cardiovascular disease deserves greater attention from both the cardiovascular and psychiatric investigator. These new treatments [to increase positive affect] could open an exciting potential new approach for treating patients with known cardiovascular disease who develop depression. If the observations and hypotheses stimulate further investigation regarding the effect of increased positive affect on physiological abnormalities associated with cardiovascular risk, perhaps it will be time for all of us to smile.”