US researchers found better levels of "good
cholesterol" and other markers of heart health in the blood of middle-aged
study subjects with a sunny outlook on life.At least some of the
connection between optimism and blood lipids in the new study appeared to
result from the optimists' tendency to have a healthy body weight and a
"prudent" diet, according to the researchers.
"It is one additional piece of evidence suggesting that
our psychological health and physical health are intertwined, and that viewing
the world optimistically may have some tangible benefits for our health,"
said lead author Julia Boehm, a research fellow at the Harvard School of Public
Health in Boston.
How the study was
Previous research by Boehm and her colleagues had shown a
link between optimism and lowered heart attack risk. So they decided to look at
whether there was an independent connection between optimistic or pessimistic
outlooks and cholesterol, which is known to play a role in heart attack risk.
The group analysed data from the Midlife in the United
States study, which included phone interviews and lab tests for 990 people aged
40 to 70. Based on the interviews, participants' levels of optimism were rated
on a scale from 6 to 30 depending on their agreement or disagreement with
statements like, "In uncertain times I usually expect the best."
According to results published in The American Journal of Cardiology, people with higher optimism
scores also had more high-density lipoproteins (HDL), the desirable form of
cholesterol that is believed to protect against heart disease.
Connection between optimism
and total cholesterol levels
They also had lower levels of triglycerides, the fatty
molecules involved in hardening of the arteries. There was no connection
between optimism and total cholesterol levels, or to low-density lipoproteins
(LDL), the "bad cholesterol."For every increase of 5 points on the
optimism scale, however, HDL in the blood increased by 1 milligram per
That same HDL increase would translate to a three percent
reduction in the risk for heart disease, experts said. For comparison, regular
exercise can decrease heart disease risk by six percent."Honestly I'm not
surprised, this is what I expect," said Dr Franz Messerli, a cardiologist
at St Luke's-Roosevelt Hospital in New York, who was not involved in the study.
It's still impossible to say whether optimism causes a
change in cholesterol, or cholesterol influences outlook, or both are subject
to some third variable, according to Messerli."In the case we have here,
we really don't know what is the chicken and what is the egg," he told
Daily lifestyle including
diet and nutrition
Boehm's group did try to account for other influences, and
when they factored-in lifestyles - including diet and alcohol consumption, and
body weight - the link between optimism and blood fats became weaker.
That suggests the optimists' tendency to have healthier
lifestyles and weight may explain "in part" the differences in their
blood lipids, the researchers conclude."If you're a forward looking,
positive individual, that attitude appears to have broad, far reaching consequences
in areas of your life," said Dr Hilary Tindle, who studies mind-body
medicine at the University of Pittsburgh but wasn't involved with the new
Conversely, risk of heart attack and stroke goes up in
depressed people, Messerli points out. "But nobody has shown the opposite,
that all of a sudden if you go from a pessimist to an optimist your risk goes
down."Because the current study only found a link to blood lipids, but not
to heart disease or cardiovascular "events," more research is needed,
the experts agreed.
The time when attitude adjustments could be used in pursuit
of physical health is still a long way off, Messerli said.