Positive Emotions Protect
Us Against Heart Disease
People who are usually happy, enthusiastic and content are less
likely to develop heart disease than those who tend not to be
happy, according to a major new study published today.
The authors believe that the study, published in the Europe's
leading cardiology journal, the European Heart Journal, is the
first to show such an independent relationship between positive
emotions and coronary heart disease.
Dr Karina Davidson, who led the research, said that although
this was an observational study, her study did suggest that it
might be possible to help prevent heart disease by enhancing people's
positive emotions. However, she cautioned that it would be premature
to make clinical recommendations without clinical trials to investigate
the findings further.
"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 (New York, USA).
Over a period of ten years, Dr Davidson and her colleagues followed
1,739 healthy adults (862 men and 877 women) who were participating
in the 1995 Nova Scotia Health Survey. At the start of the study,
trained nurses assessed the participants' risk of heart disease
and, with both self-reporting and clinical assessment, they measured
symptoms of depression, hostility, anxiety and the degree of expression
of positive emotions, which is known as "positive affect".
Positive affect is defined as the experience of pleasurable emotions
such as joy, happiness, excitement, enthusiasm and contentment.
These feelings can be transient, but they are usually stable and
trait-like, particularly in 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
After taking account of age, sex, cardiovascular risk factors
and negative emotions, the researchers found that, over the ten-year
period, increased positive affect predicted less risk of heart
disease by 22% per point on a five-point scale measuring levels
of positive affect expression (ranging from "none" to
Dr Davidson said: "Participants with no positive affect
were at a 22% higher risk of ischaemic 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
"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 speculate about what could be the possible mechanisms
by which positive emotions might be responsible for conferring
long-term protection from heart disease. These include influence
on heart rates, sleeping patterns and smoking cessation.
"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."
She said that most successful interventions for depression include
increasing positive affect as well as decreasing negative affect.
If clinical trials supported the findings of this study, then
it would be relatively easy to assess positive affect in patients
and suggest interventions to improve it to help prevent heart
disease. In the meantime, people reading about this research could
take some 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)."
In an accompanying editorial by Bertram Pitt, Professor of Internal
Medicine, and Patricia Deldin, Associate Professor of Psychology
and Psychiatry, both at the University of Michigan School of Medicine
(Michigan, USA), the authors pointed out that, currently, no-one
knew whether positive affect had a direct or indirect causal role
in heart disease, or whether there was a third, underlying factor
at work, common to both conditions. Nor was it known for certain
whether it was possible to modify and improve positive affect,
and to what extent.
"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 investigators
new treatments [to increase positive affect] could open an exciting
potential new approach for treating patients with known cardiovascular
disease who develop depression. If Davidson et al.'s 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
February 18, 2010