Who said work was a killer?

Whoever said that work can be a killer was right and the latest research proves it!

According to a new study stress at work increases the risk of heart disease by disrupting the body's internal systems.

Scientists from University College London conducted a long-term study on the the effects of stress from everyday working life on heart disease.

The study involved 10,308 London based civil servants who were tracked from 1985 and is say the researchers the first large-scale population study of its kind.

Epidemiologist Dr. Tarani Chandola says people have been skeptical about whether work stress really affects a person biologically and that has been a problem.

Dr. Chandola, who led the study, suggests that stress-induced biological changes may play a more direct role than previously thought.

The world's leading cause of death is heart disease and it is caused by fatty deposits that harden and block arteries and high blood pressure which damages blood vessels, as well as other factors.

For the study the researchers measured stress among the civil servants by asking questions about their job demands such as how much control they had at work, how often they took breaks, and how pressed for time they were during the day.

Over a 12-year period seven surveys were conducted and it was found that chronically stressed workers had a 68 percent higher risk of developing heart disease and the link was strongest among people under 50.

Chandola says the study adds to the growing evidence that work stress-coronary and heart disease are linked.

The researchers say stress at work causes heart disease by both behavioral and biological changes, stressed workers eat unhealthy food, smoke, drink and skip exercise which are all behaviours linked to heart disease.

Stressed workers were also found to have lowered heart rate variability which is a sign of a poorly-functioning weak heart, and higher-than-normal levels of the "stress" hormone cortisol; too much cortisol circulating in the blood stream can damage blood vessels and the heart.

Dr. Chandola says if a person is constantly stressed out these biological stress systems become abnormal.

The study is published in the European Heart Journal.