Working more than 55 hours a week significantly increases the risk of stroke and deaths from heart disease, a new study has concluded.
The World Health Organization (WHO) and the International Labour Organization (ILO) said the research was the first global analysis of the impact of clocking up excessive hours on death and health generally.
The study estimates long working hours caused 745,000 deaths worldwide in 2016, up by 29% since 2000.
Compared with working 35 to 40 hours a week, those working more than 55 saw their risk of heart disease increase by 17 per cent, while there was a 35 per cent hike in the risk of stroke.
Researchers found 9% of the global population worked at least 55 hours a week in 2016, and that percentage is still growing.
From 2000 to 2016, in relative terms, the proportion of the population working long hours has also increased by 9%.
Europe world’s least affected region
Europe was the region with the lowest percentage of people working long hours.
South-East Asia had the highest proportion of people working long hours, at 11.7 per cent, followed closely by Africa and the Eastern Mediterranean.
In Europe, the figure was just 3.5 per cent.
Europe was also the only region not to see an increase in deaths between 2000 and 2016, although Ukraine was highlighted as having the highest estimated death rate from heart disease attributable to long hours, alongside Egypt and Lebanon.
It saw around 15 deaths per 100,000 in the population, as compared to 0.6-0.7 in countries like France which had the lowest rates.
The countries with the lowest proportions of the population working more than 55 hours a week were Bulgaria, Lithuania and Romania.
Long working hours increase the risk of heart disease and stroke for two reasons, according to the authors.
Firstly they activate the nervous system and immune system, in turn causing an excessive release of stress hormones such as adrenaline and cortisol. This causes low heart rate or sustained high blood pressure and legions that can lead to the formation of fatty deposits in blood vessels.
Secondly, long hours can lead to increased use of harmful substances such as tobacco, alcohol, unhealthy food, as well as lack of physical activity, impaired sleep, and poor recovery.
“Working 55 hours or more per week is a serious health hazard,” said Dr Maria Neira, director of the environment, climate change and health department at WHO.
“It’s time that we all, governments, employers, and employees wake up to the fact that long working hours can lead to premature death."
The study, published in Environment International, did not find meaningful results for working weeks between 40 to 55 hours.
Data was almost exclusively collected by countries through their national statistical offices.
The organisations estimate that, in 2016, 398,000 people died from stroke and 347,000 from heart disease as a result of having worked at least 55 hours a week.
Between 2000 and 2016, the number of deaths from heart disease due to working long hours increased by 42%, and from stroke by 19%.
The disease burden was particularly prevalent in men, accounting for 72 per cent of deaths.