Doctors have long known that a stressed life does the heart no favours, and new research may help unravel why that's so.
Real value for patients
A Harvard team says heightened activity in a key part of the brain may explain why stress boosts people's odds for heart disease and stroke.
The finding "raises the possibility that reducing stress could produce benefits that extend beyond an improved sense of psychological well-being", said study lead author Dr Ahmed Tawakol, who co-directs the cardiac imaging programme at Massachusetts General Hospital in Boston.
One neurologist agreed that the research could have real value for patients.
"This study provides information that can help us better understand the mechanisms in which the body and the brain affect each other," said Dr Jeffrey Borenstein. He is president of the Brain & Behaviour Foundation in New York City.
"A better understanding of this link can help us develop methods of prevention" of heart disease, Borenstein said.
According to Tawakol's team, smoking, high blood pressure and diabetes are well-known risk factors for heart disease and stroke, as is chronic mental stress.
The missing link
But what exactly is the link between stress and the heart? To find out, the researchers tracked the health of nearly 300 people for an average of about four years. During that time, 22 were diagnosed with a heart attack, angina (chest pain), heart failure, stroke or peripheral artery disease (poor circulation in the legs).
Using PET and CT scans, the investigators found that people with elevated levels of activity in the amygdala – a small region of the brain closely tied to stress – were at higher risk for heart disease and stroke.
These people also developed heart problems sooner than people with lower levels of activity in the amygdala, the findings showed.
"Our results provide a unique insight into how stress may lead to cardiovascular disease," Tawakol said in a news release from the journal The Lancet. His team published their findings in the journal.
"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," Tawakol believes.
Dr Salman Azhar, who directs stroke services at Lenox Hill Hospital in New York City, applauded the new research.
Azhar described the amygdala as "a football-shaped collection of nerve cells in the brain that influences how we respond to stress".
'Stress ball' in our brain
Using brain scans, Tawakol's group highlighted "a 'street map' that started the amygdala lighting up. That led to the blood vessels lighting up, and that led to more chest pain, heart attacks and strokes", Azhar explained.
And while stress is unavoidable in life, there are steps to take to minimise it – and shield hearts in the process, he said.
"What matters is how we react to stress," Azhar said. "If we manage stress well with strategies like 'don't sweat the small stuff' and meditation, we might be able to change how this 'stress ball' in our brain responds, and actually decrease our chances of having a heart attack."
Azhar said that in his own practice, he has "been using mindfulness as a tool to help patients who are at risk for stroke reduce the intensity of their stress reactions for some time now".