Being in a stressful job where you are bossed around could raise the risk of a heart attack by a quarter, warn researchers.
They said workers who feel over-pressured yet powerless are more at danger than counterparts who suffer less stress.
Their major review of heart health among 200,000 workers examined the risk for all occupations, from civil servants to factory workers.
‘Our findings indicate that job strain is associated with a small but consistent increased risk of experiencing a first coronary heart disease event, such as a heart attack,’ said Mika Kivimaki, who led the University College London research.
Previous research has suggested stress at work can trigger heart problems but there have been conflicting results.
The UCL investigation pooled results from 13 studies in the UK, Belgium, Denmark, Finland, France, the Netherlands and Sweden between 1985 and 2006.
All the men and women taking part completed questionnaires about their jobs, workload, deadlines and freedom to make decisions.
None had suffered a heart attack before providing the details, says a report in The Lancet medical journal.
The researchers defined a stressful job as one involving a high workload coupled with little freedom to make decisions.
Over an average follow-up period of 7.5 years, researchers recorded 2,356 cases of heart disease. These included hospital admissions due to heart attacks and deaths from coronary failure.
Scientists found those in stressful jobs are 23 per cent more likely to experience such an event than the less stressed. The greater risk reported for people in stressful jobs remained after taking into account factors such as lifestyle, age, gender and socio-economic background.
Professor Kivimaki said job stress may account for a ‘notable proportion’ of heart problems in the working population.
He pointed out that stress reduction would have a much smaller impact than tackling either lack of exercise or smoking, which had a negative effect ten times greater.
Research from a long running survey of Whitehall civil servants was included in the study, which showed working long hours raised the risk of fatal heart attacks by up to 60 per cent.