Scientists finally discover how stress causes heart attacks and strokes

For years experts have puzzled as to how chronic anxiety leads to heart problems.

But now scientists have found that people who have heightened activity in a part of the brain linked to stress - the amygdala - are more likely to develop cardiovascular believe. The amygdala is responsible for telling the bone marrow to temporarily produce more white blood cells which fight infection and repair damage. It essentially prepares the body for a harmful experience, such as being punched and would have been vital to survival in our evolutionary past. White blood cells help fight infection and repair damage but too many can be deadly

However in the modern world, chronic stress can lead to the over-production of white blood cells, which can form plaques in the arteries and lead to heart disease, scientists believe. “Our results provide a unique insight into how stress may lead to cardiovascular disease,” said lead author Dr Ahmed Tawakol of Harvard Medical School, and Massachusetts General Hospital. “This raises the possibility that reducing stress could produce benefits that extend beyond an improved sense of psychological well-being. “Eventually, chronic stress could be treated as an important risk factor for cardiovascular disease, which is routinely screened for and effectively managed like other major cardiovascular disease risk factors.”

Smoking, high blood pressure and diabetes are already well-known risk factors for cardiovascular disease but researchers say that chronic social stress should also now be considered a major danger.

In this study, 293 patients were given scans to record the activity of their brain, bone marrow, spleen and inflammation of their arteries. They were then tracked for an average of 3.7 years to see if they developed cardiovascular disease.

In this time 22 patients had cardiovascular events including heart attack, angina, heart failure, stroke and peripheral arterial disease. Those with higher amygdala activity had a greater risk of subsequent cardiovascular disease and developed problems sooner than those with lower activity.

The researchers also found that the heightened activity in the amygdala was linked to increased bone marrow activity and inflammation in the arteries, and suggest that this may cause the increased cardiovascular risk. Dr Ilze Bot, Leiden Academic Centre for Drug Research, Leiden University, The Netherlands, said: “In the past decade, more and more individuals experience psychosocial stress on a daily basis.” “Heavy workloads, job insecurity, or living in poverty are circumstances that can result in chronically increased stress, which in turn can lead to chronic psychological disorders such as depression.

“These clinical data establish a connection between stress and cardiovascular disease, thus identifying chronic stress as a true risk factor for acute cardiovascular syndromes, which could, given the increasing number of individuals with chronic stress, be included in risk assessments of cardiovascular disease in daily clinical practice.”

The research was published in The Lancet.