When the study began in 1973, none of the chosen staff had any history of heart disease but, by the time it finished, quite a number had developed cardiovascular problems from which they had died. The basic question was: had work stress killed them?

The answer is yes - but it’s not that simple. The real culprit was found not to be 'high job strain' alone; it was work stress plus the negative psychological factors associated with the particular job that caused health problems.

Jobs that were demanding, but offered employees little 'job control' were found to more than double the risk of death from heart disease. These people also tended to put on more weight than their colleagues.

It was a very similar picture with staff who suffered from an 'effort-reward imbalance' - defined as low salary, lack of social approval, and few career opportunities relative to the demands of the job.

However, those in stressful jobs per se had no extra risk of heart disease at all - although, as the authors point out, the risk may rise if you have a very high workload (working continuously for at least 11 hours a day).

The findings that stress alone won’t kill you confirms the theories developed in the 1930s by German stress pioneer Hans Selye, who coined the term ‘eustress’ to denote positive stress with rewarding outcomes - a happy state which, he said, might even be health-promoting (BMJ, 2002; 325: 857-60).