A stressful job has a direct biological
impact on the body, raising the risk of heart disease,
research has indicated.
The study reported in the European Heart
Journal focused on more than 10,000 British civil servants.
Those under 50 who said their work was
stressful were nearly 70% more likely to develop heart
disease than the stress-free.
The stressed had less time to exercise
and eat well - but they also showed signs of important
The studies of Whitehall employees -
from mandarins to messengers - started in the 1960s, but
this particular cohort has been followed since 1985.
As well as documenting how workers felt
about their job, researchers monitored heart rate variability,
blood pressure, and the amount of the stress hormone cortisol
in the blood.
They also took notes about diet, exercise,
smoking and drinking.
Then they found out how many people had
developed coronary heart disease (CHD) or suffered a heart
attack and how many had died of it.
Lead researcher Dr Tarani Chandola, of
University College London, said: "During 12 years of follow
up, we found that chronic work stress was associated with
CHD and this association was stronger both among men and
women aged under 50.
"Among people of retirement age - and
therefore less likely to be exposed to work stress - the
effect on CHD was less strong."
On the one hand, those who reported stressful
jobs appeared less likely to eat sufficient amounts of
fruit and vegetables, and were less likely to exercise
- although problem drinking did not emerge as a significant
problem in this study.
Lifestyle, the researchers concluded,
was nonetheless a key factor in the development of the
But the team also say they are now confident
they understand the biological mechanisms that link stress
and disease, a connection widely held to exist but which
has been difficult to prove.
These mechanisms held true regardless
Stress appeared to upset the part of
the nervous system which controls the heart, telling it
how to work and controlling the variability of the heart
Those who reported stress were also recorded
as having poor "vagal tone" - the impulses which regulate
A major part of the neuroendocrine system
- which releases hormones - also seemed to be disturbed
by stress, evidenced by the fact that anxious workers
had higher levels of the stress hormone cortisol in the
While the younger worker seemed to be
more at risk, the findings were the same regardless of
the status of the worker.
Previous studies had suggested those
of lower employment grades may be more at risk.
"We did not find strong evidence that
the effect of work stress on heart disease is worse for
those in lower grades - the effect of stress was pretty
much the same across different grades," said Dr Chandola.
"However, later on in the study, some
parts of the civil service underwent considerable change
in their working environments, including privatisation.
"We are currently exploring whether the
effects of these changed work stress levels, partly brought
about by privatisation, are particularly deleterious for
those in the low grades of the civil service."
The British Heart Foundation said the
research added to our understanding of how stress at work
may alter the body's chemistry.
"The study also reinforces what has been
identified by previous research, that stress at work is
often associated with unhealthy behaviours such as smoking,
lack of exercise and a poor diet - all which can impact
on heart health," said June Davison.
"There are many ways that we can help
ourselves by learning how to cope with stressful situations.
"Keeping fit and active also helps to
relieve stress and therefore reduce the risk of heart