Previous studies have pointed out stress to be the major culprit behind heart attacks and various other heart complaints, but with very less evidence to support it.

Researchers at University College, London, have now revealed that they have been able to show that those who encounter stress are more likely to suffer from hardened arteries than those who remain calm under pressure.

Stress actually increases the risk of heart attacks and strokes, say researchers, challenging conventional medical wisdom that there is no evidence of a link between mental pressure and heart conditions.

Their study, published in the European Heart Journal, involved 514 men and women, with an average age of 62 with none of them showing signs of heart disease at the time of the test.

Each one of them was made to undergo a stressful situation by being asked to carry out tricky mental tests thereby measuring the levels of stress hormone cortisol in their saliva.

The ones who experienced increased in the tests were twice as likely to have furred arteries as those who remained calm, the study in the European Heart Journal found.

In addition, volunteers' arteries were also scanned in order to see if there is any accumulation of fatty material on the inside walls of the arteries.

Coronary heart disease is Britain's biggest disease, engulfing 105,000 lives every year. Around 230,000 suffer from a heart attack each year, while 2.6 million enduring coronary heart disease.