Doctors Link Stress To White Blood Cell Production

BOSTON (CBS) - Chronic stress has been linked to heart disease for decades, but the exact connection hasn't always been clear.

Does it lead to high blood pressure and that causes the heart disease?

Researchers at Massachusetts General Hospital have found that your bone marrow may play a key role. Bone marrow is where blood cells are made, including white blood cells which fight off infection.

Dr. Matthias Nahrendorf and his colleagues found that in mice who were exposed to stress, their bone marrow churned out more of these white blood cells.

Researchers then looked at 29 stressed out "doctors-in-training" working grueling hours in a medical ICU.

"They are very worried and they're at a time in their career," explains Dr. Nahrendorf. "When their experience levels don't quite match the challenge."

They found that the young doctors, also, after a week of persistent stress, had higher levels of white blood cells. And over the long-run, that could be bad for the heart.

"So, there is an increased output of these white blood cells and they travel through the bloodstream to atherosclerotic plaque and make these plaques more inflamed," says Dr. Nahrendorf. "So, they migrate to the vessel wall, for instance, in coronary arteries and they make this plaque rupture and that causes heart attacks."

Dr. Nahrendorf says if they can figure out the connection between stress and white blood cell production, they could develop drugs to break the cycle.

In the meantime, there are two things you can do to protect yourself from stress. Try to get rid of what's bothering you, easier said than done, or do things to counteract the effects. For example, exercise not only relieves stress, but is also good for your heart.

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