Stressed employees are at higher risk of heart attacks even if they are otherwise healthy, a study by UCL researchers suggests.
Analysis of 13 different European studies found those workers who had busy jobs but little control over how their work was managed were 23% more likely to suffer a heart attack.
Research leader Professor Mika Kivimäki said if the association was causal, job strain would account for a notable proportion of coronary heart disease events in working populations.
"As such, reducing workplace stress might decrease disease incidence," he said.
"However, this strategy would have a much smaller effect than tackling standard risk factors such as smoking and physical inactivity."
The analysis of research involving nearly 200,000 people across Europe offers the most comprehensive picture so far - previous studies had been criticised for inconsistent findings, limited scope and methodological shortcomings.
The full study was published in The Lancet today.
It comes after a leading employment lawyer warned that employers were "treading on eggshells" if they did not support stressed employees in the workplace.