Studies have proved that stress increases the risk of heart attacks and strokes. The study questions earlier medical wisdom that mental pressure was linked to heart conditions.

Researchers from University College, London, claim that those under stress are likely to suffer from hardened arteries.

About 514 men and women, with an average age of 62, were put under a study. All those who were put under observation did not have heart disease at the time of the test.

Every participant was put under stress tests and their cortisol, which is produced by the body when it comes under mental or physical strain, levels and hormone levels were measured. Arteries were also checked to find out any kind of fatty material accumulation on the inner linings of arteries.

The study in the European Heart Journal found that people who came under stress by the tests had two times more chances of having furred arteries.

Prof Avijit Lahiri, a cardiologist, said, "This study shows a clear-cut relationship between stress and silent coronary artery disease. This is the first clear proof."

The British Heart Foundation however claimed that stress was not directly linked to cardiovascular disease. The foundation's website states that due to stress people tend to smoke, drink, and overeat that causes heart attacks.