People who work long hours are significantly more likely to suffer a stroke, research suggests.
A study found employees who juggle a demanding 10 hour work schedule every day for at least a decade are 45 per cent more likely to develop the life-threatening condition.
And, in a result that baffled the French researchers, the under 50s were more at risk than their older colleagues.
The research was carried out by Paris Hospital, Versailles, and led by Professor Alexis Descatha, of the occupational health unit.
Britons have been found to have the longest working days of anywhere in Europe.
Irregular shifts, night work and the strain of a high-pressure job have all been blamed for poor health among employees.
To uncover how the working day may affect the risk of stroke, the researchers started analysing the hours of 143,592 French workers in 2012.
Of these volunteers, 42,542 (29 per cent) reported having long hours, which was defined as working more than 10 hours at a time for at least 50 days a year.
Around one in ten of the study’s hard grafters claimed they had worked these hours for at least a decade.
Over the next seven years, 1,224 of the volunteers suffered a stroke.
Results – published in the journal Stroke – revealed those who reported working long hours had a 29 per cent greater risk of the life-threatening condition.
And the odds rose to 45 per cent for the 14,481 (10 per cent) who had done this for a decade or more.
This remained true even after the researchers adjusted for any other heart-related risk factors or previous strokes.
Surprisingly, the participants, who were aged between 18 and 69, were more at risk if they were younger.
‘The association between 10 years of long-work hours and stroke seemed stronger for people under the age of 50,’ Professor Descatha said.
‘This was unexpected. Further research is needed to explore this finding.’
The scientists particularly worry about the wellbeing of healthcare workers, who are typically forced to endure long shifts.
‘I would also emphasise many healthcare providers work much more than the definition of long working hours and may also be at higher risk of stroke,’ Professor Descatha said.
‘As a clinician, I will advise my patients to work more efficiently and plan to follow my own advice.’
Business owners, CEOs, farmers, professionals and managers have previously been found to suffer the effects of a long-working day.
However, the French researchers argue these employees may have more control over their hours.
The researchers did not speculate as to why people who work long shifts are more likely to suffer a stroke.
But sitting down for too long – a problem rife among office workers – can lead to obesity and raise blood pressure, which the NHS warns can raise the risk of strokes.
Other studies have also suggested a similar danger for those who work long hours.
A two-year study of more than 85,500 British and Scandinavian employees found those who worked at least 55 hours a week were 40 per cent more likely to develop atrial fibrillation over the next decade than those who put in the ‘normal’ 35-to-40.
Atrial fibrillation is defined as an abnormally fast, irregular heart rate. The condition affects around one million people in the UK, and can lead to stroke, heart failure or even dementia.
A 2015 international study of more than 600,000 people found the risk of developing stroke increased by a third in those who worked more than 55 hours a week compared to those who stuck to the traditional ‘9-to-5’ day.
And their odds of developing heart disease rose 13 per cent.