A recent study, published in the Lancet medical journal, reported that protracted working hours increase the risk of stroke by up to 33%.

The study said the more number of hours you work; the higher is your stroke risk. Those working 41-48 hours per week had a 10% higher risk; those working 49-54 hours/week had a 27% higher risk and for those working 55 hours a week, the risk increased by 33%, the report revealed. This study, one of the largest studies on the issue was led by researchers from University College, London, and conducted across three continents.

Risk of stroke for people working long hours was connected to three other probable factors, including higher alcohol consumption, stress and physical inactivity. Physical inactivity increases the risk of stroke through different biological reactions and alcohol consumption is a contributing factor, because people working long hours are more prone to heavy drinking. The Lancet report was based on a review of 17 studies which followed and collected data of 528,908 people over a 7.2 year average. The increased risk of stroke remained after taking into account higher alcohol consumption, stress and physical inactivity.

Longer working hours also upped the risk of coronary heart diseases by 13% after accounting for other risk factors such as socioeconomic status, age and sex. For the study on coronary heart disease, the research team separately compiled and reviewed 25 studies that tracked data on over 600,000 people from USA, Australia and Europe. Data was collected and tracked for an average of 8½ years.

The causes related to heart diseases and stroke is a complex study combining environmental and genetic factors. But experts opined that the three factors that were a certain risk include higher alcohol consumption, stress and physical inactivity. The outcome from this study reaffirmed the results of earlier studies linking lengthy working hours to increased health risks. This study also urged doctors to pay specific attention to cardiovascular risk when they advise people working long hours.

Other experts who were not part of this study were taking these outcomes seriously and pointed to stark differences across countries over an average working week. Lengthy working hours is not insignificant, said Urban Janlert from Sweden’s Umea University. Although some countries have legislation to restrict working hours, laws were not being implemented, Janlert said. Among the developed countries, Turkey had 43% of working people putting in 50 hours, while in Netherlands; this proportion was less than 1%.