If you adhere to the old cliché that "hard work never hurt anybody", you might want to reconsider. Because according to a study by researchers from University College London, working more than 11 hours a day increases the risk of heart disease by 67 per cent.
The findings, published in the journal "Annals of Internal Medicine", are the latest to be released from one of the longest-running studies of its kind ever carried out, which has been following the health of more than 10,000 British civil servants since 1985.
For this study, the researchers selected more than 7,000 people with no history of heart disease and gathered data on risk factors such as age, blood pressure, cholesterol, smoking and diabetes. They also asked participants how many hours they worked.
During an 11-year period, 192 participants had heart attacks, with those who worked 11 hours or more a day 67 per cent more likely to have a heart attack than those working a normal 8 hour day.
"Working long days is associated with a remarkable increase in risk of heart disease," said Mika Kivimaki, who led the research.
However he added that it was not yet clear whether long hours themselves contribute to heart disease risk, or whether they exacerbate other factors that impact cardiac health such as diet or a lack of exercise.
However other studies, notably by the Fukuoka Heart Study Group in Japan, have found that working over 60 hours a week and missing out on sleep can as much as double the chances of a heart attack for the 40+ age group.
And the same University College team have previously found that workers with heavy workloads and little control over decisions affecting their working lives are 68 per cent more likely to suffer from coronary heart disease than workers who had less stressful jobs.
Stephen Holgate of the Medical Research Council, said that the stud was a "wake-up call for people who overwork themselves."
"This study might make us think twice about the old adage 'hard work won't kill you'," he added.
Professor Peter Weissberg, medical director at the British Heart Foundation, acknowledged that the findings raise the possibility that long working hours may increase the risk of a heart attack.
But he added that "further studies are required to confirm this association and clarify how it might be used to change our current approach to assessing someone's risk of developing heart disease and what advice we give on working conditions."
