New Harvard Research Tells How Meditation Calms Stress

Researchers at the Medical School reported in a study published in the Jan. 8 issue of "Science" how meditation helps to lower blood pressure and heart rate in stressful situations.

Meditation as a technique to relieve stress has been known for centuries, but no one knew how it worked, Dr. Herbert Benson, associate professor at the Medical School and co-author of the study, said yesterday. The researchers concluded from the three-year study that meditation blocks the effect on the body of norepinephrine, an "emergency hormone" secreted in response to stress.

The body's usual response to stress, known as the "fight or flight response," is increased heart and breathing rates, blood pressure and muscle tension caused by the secretion of norepinephrine, Benson said. The body's "relaxation response," which can be brought about by meditation, counteracts the effects of the fight or flight response and causes relief from stress.

The researchers wanted answers to two questions, Benson said. They were puzzled as to why, in people who produce the relaxation response by meditation, norepinephrine levels in the blood are not decreased as are blood pressure and heart rate. They also wanted to know why the calming effects of the relaxation response are carried over into periods of the day during which the person is not actively producing the response.

The study found that during stress, people who meditate still produce norepinephrine, but the hormone's effect is blocked, Benson said. This explains why hormone levels are not decreased while the calming effect is still observed, Benson said, adding that it also explains the carry over effect, because the body's response remains altered. Benson said that in persons who meditate, the fight or flight response can still be produced by norepinephrine, but that it takes larger amounts of the hormone to overcome the effects of meditation.

Exactly how norepinephrin is blocked, as well as how a thought process such as meditation is translated into a physiological calming effect, is still unclear, Benson said, adding, "But it's something we've started to investigate."