The mind-body connection is more
than just a catchphrase: A new study
finds that increased levels of stress are
indeed linked to greater risk of a heart
attack or stroke.
Researchers found that the people
in the study who had more activity
in an area of the brain that regulates
the body’s response to stress and fear,
called the amygdala, were more likely
to have a heart attack or stroke than
those with less activity in the amygdala,
according to the study.
“This study identifies, for the first
time in animal models or humans, the
region of the brain that links stress to
the risk of heart attack or stroke,” lead
study author Dr. Ahmed Tawakol, a
cardiologist at Massachusetts General
Hospital in Boston, said in a statement.
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In addition, the researchers also linked
increased activity in the amygdala
to several processes that play a role
in the development of heart disease,
according to the study, published today
(Jan. 11) in the journal The Lancet.
“While the link between stress and
heart disease has long been established,
the mechanism mediating that risk has
not been clearly understood,” Tawakol
In the study, the researchers looked
at two groups of patients, the first of
which included nearly 300 adults ages
30 and up. At the start of the study,
none of the patients had heart disease.
The researchers performed brain scans
on the patients using a technique that
not only measured brain activity levels
but also allowed the researchers to look
at levels of blood vessel inflammation
and bone marrow activity throughout
the body.
During the average follow-up period
of 3.7 years, 22 of the patients had a
medical event related to heart disease,
such as a heart attack, stroke or diagnosis
of heart failure. The researchers found
that increased activity levels in the
amygdala at the beginning of the study
were linked to a significantly higher risk
of having a cardiovascular event later
And the higher the levels of activity
were in the amygdala at the study’s
start, the sooner these events occurred,
the researchers found.
In addition, heightened activity in the
amygdala was associated with greater
amounts of inflammation in the blood
vessels and higher levels of activity in
the parts of the bone marrow where new
blood cells are made, according to the
Both inflammation in the blood
vessels and increased bone marrow
activity can contribute to a condition
called atherosclerosis, which increases a
person’s risk for heart disease, according
to the study. In animal studies,
researchers have found that stress
activates the bone marrow, prompting
it to produce white blood cells, which
leads to inflammation, Tawakol said.
“This study suggests an analogous path
exists in humans,” he added.
The second, smaller group of patients
in the study included 13 people with
chronic stress disorders, such as posttraumatic
stress disorder. These patients
were asked to complete a questionnaire
about their perceived stress levels, as
well as undergo brain scans to measure
the levels of activity in their amygdalae.
The researchers also measured the
patients’ blood vessel inflammation
They found that the patients’ perceived
stress levels were linked to increased
activity in the amygdala as well as
increased levels of inflammation in the
blood vessels.
The new study “provides more
evidence of a heart-brain connection”
by elucidating a link between
activity in the amygdala, which is
a marker of stress, and subsequent
cardiovascular events, Zahi Fayad,
a senior author of the study and the
director of the Translational and
Molecular Imaging Institute at the
Icahn School of Medicine at Mount
Sinai in New York City, said in a
The link between amygdala activity
and risk of heart attack or stroke
held up even after the researchers
controlled for risk factors for heart
disease, Fayad added.
Although more studies are
needed to look into the effects
of stress reduction on heart
disease risk, Tawakol noted that
the “findings suggest several
potential opportunities to reduce
cardiovascular risk attributable to
For example, “it would be
reasonable to advise” people with an
increased risk of heart disease to try
stress-reduction techniques if they
feel they have a lot of stress, he said.
Additionally, drugmakers may
be able to target some of the
mechanisms highlighted in the study
to develop new drugs to treat heart
disease, Tawakol said.
Live Science: Sara G. Miller

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