Work-related stress can kill, study finds

Work really can kill you, according to a study
on Wednesday providing the strongest evidence yet of how on-the-job
stress raises the risk of heart disease by disrupting the body's
internal systems.

The
findings from a long-running study involving more than 10,000 British
civil servants also suggest stress-induced biological changes may play
a more direct role than previously thought, said Tarani Chandola, an
epidemiologist at University College London.
"This
is the first large-scale population study looking at the effects of
stress measured from everyday working life on heart disease," said
Chandola, who led the study. "One of the problems is people have been
skeptical whether work stress really affects a person biologically."
Heart disease is the world's leading cause of death. It is caused by
fatty deposits that harden and block arteries, high blood pressure
which damages blood vessels, and other factors.
The researchers measured stress among the
civil servants by asking questions about their job demands such as how
much control they had at work, how often they took breaks, and how
pressed for time they were during the day.

The
team conducted seven surveys over a 12-year period and found
chronically stressed workers — people determined to be under severe
pressure in the first two of the surveys — had a 68 percent higher risk
of developing heart disease.
The link was strongest among people under 50, Chandola said.
"This
study adds to the evidence that the work stress-coronary heart disease
association is causal in nature," the researchers wrote in the European
Heart Journal.
Behavior
and biological changes likely explain why stress at work causes heart
disease, Chandola said. For one, stressed workers eat unhealthy food,
smoke, drink and skip exercise — all behaviors linked to heart disease.
In
the study, stressed workers also had lowered heart rate variability — a
sign of a poorly-functioning weak heart — and higher-than-normal levels
of cortisol, a "stress" hormone that provides a burst of energy for a
fight-or-flight response.
Too much cortisol circulating in the blood stream can damage blood vessels and the heart, Chandola said.
"If you are constantly stressed out these biological stress systems become abnormal," Chandola said.