US researchers believe they have uncovered how stress raises the risk of a heart attack. Photo: Sebastian Costanzo
Paris: Scientists say they may have unravelled how chronic stress leads to heart attack and stroke by triggering overproduction of disease-fighting white blood cells which can be harmful in excess.
They say surplus cells clump together on the inner walls of arteries, restricting blood flow and encouraging the formation of clots that block circulation or break off and travel to another part of the body.
White blood cells “are important to fight infection and healing, but if you have too many of them, or they are in the wrong place, they can be harmful,” study co-author Matthias Nahrendorf of the Harvard Medical School in Boston said on Sunday.
Doctors have long known chronic stress leads to cardiovascular disease but have not understood the mechanism.