The association is particularly strong among those who have worked long hours for a decade or more, according to the research published in Stroke, the journal of the American Heart Association.

Researchers found that participants working long hours had a 29% greater risk of stroke, while those working long hours for 10 years or more had a 45% greater risk of stroke.

Long hours were defined in the French study as working more than 10 hours on at least 50 days per year.

Researchers from Angers University and the French National Institute of Health and Medical Research looked at data on age, smoking and working hours covering more than 143,000 adults. Each participant also had a medical interview with a doctor.

Part-time workers and those who suffered strokes before working long hours were excluded from the study.

Dr Alexis Descatha, who led the research, said that the association between 10 years of long work hours and stroke was stronger for people under the age of 50.

This is not the first time that research has linked stoke with long working hours. One study found that, in Japan, 60% of compensated Karoshi (death from over-work) cases were caused by stroke. A Danish study from 2018 found an association between long working hours and a particular type of stroke.

This French study is the first to investigate the association between long working hours and stroke in a large general population study.