Researchers said on Tuesday that people working
10 to 11 hours a day are more likely to suffer serious heart problems,
including heart attacks, than those only putting in seven hours.
The discovery does not provide definitive
proof that long hours cause coronary heart disease, but it does show a clear
link, which experts believe is due to stress.
There were 369 cases of death due to heart
disease, non-fatal heart attacks and angina among the 11-year study of 6,000
British civil servants. The risk of having an adverse event was 60
percent higher for those who worked three to four hours overtime.
The research showed that an extra one to
two hours beyond a normal seven-hour day was not associated with increased
“It seems there might a threshold, so
it is not so bad if you work another hour or so more than usual,” Dr.
Marianna Virtanen, an epidemiologist at the Finnish Institute of Occupational
Health and University College London told Reuters.
Heart problem risks that arose among those
working overtime was independent of a range of other risk factors like smoking,
being overweight or having high cholesterol.
However, Dr. Virtanen said it was possible
the lifestyle of people working long hours deteriorated over time, maybe due to
a result of poor diet or increased alcohol consumption.
Long hours may be associated with
work-related stress, which interferes with metabolic processes, as well as
“sickness presenteeism,” where employees continue working when they
The study was published in the European
Gordon McInnes, professor of clinical pharmacology
at the University of Glasgow’s Western Infirmary, said that the findings could
have widespread implications for doctors assessing patients’ heart risks.
“If the effect is truly causal, the
importance is much greater than commonly recognized. Overtime-induced work
stress might contribute to a substantial proportion of cardiovascular
disease,” he said.