CHICAGO - Heart disease patients who practiced meditation for four months showed slight improvements in blood pressure and insulin levels, a small, government-funded study found.
Patients who learned Transcendental Meditation did better on those measures than patients who spent the same amount of time on lectures, discussions and homework assignments about the effects of stress, diet and exercise on the heart.
The 103 heart patients participating in the study received regular medical care, including drugs for lowering cholesterol and blood pressure.
Adding meditation had "a strong enough effect that we could show a benefit over traditional health care, and traditional health care is pretty good now," said study co-author Dr. Noel Bairey Merz of Cedars-Sinai Medical Center. "I think it's a testimony to this intervention that we could see anything."
Some of the researchers involved are affiliated with the organization that teaches Transcendental Meditation around the world, raising questions about potential bias, said Jim Lane of Duke University School of Medicine, who had no part in the study.
The research team included doctors from the Maharishi University of Management in Fairfield, Iowa. The school was founded by Maharishi Mahesh Yogi, who started a movement to teach meditation worldwide and was a guru to the Beatles and the Beach Boys.
"I would like to see this replicated by other investigators, especially by those not part of the TM organization," Lane said. He is conducting similar research on meditation without the endorsement of the TM group.
Merz said she does not meditate and is not paid by the TM organization, although others on the research team were. She said the potential for bias in her study was no greater than in studies where a researcher gets financial support from a drug company.
The study appears in Monday's Archives of Internal Medicine. Funding came from the National Center for Alternative and Complementary Medicine and the National Center for Research Resources.
Transcendental Meditation involves sitting quietly and focusing on a repeated sound, called a mantra, for about 20 minutes every morning and evening. The practice traces its roots to ancient India. Today, it costs $2,500 to learn Transcendental Meditation in a series of lectures, personal instruction and group meetings.
Previous studies have found meditation can lower blood pressure, but the new study is the first to show an effect on insulin function, Lane said.
After starting either meditation or the health education program, neither group saw changes in cholesterol levels or weight. The health education group got more exercise.
The meditation group saw its average systolic blood pressure - the top number - decrease from 126 to 123. The diastolic blood pressure - the bottom reading - did not change in either group. Glucose and insulin levels dropped somewhat in the meditation group and increased slightly in the health education group.
The researchers speculated that the difference is caused by meditation decreasing the body's natural reaction to stress, possibly by lowering blood levels of the "fight or flight" hormone cortisol. Merz said the study was designed to measure cortisol levels in saliva, but the samples dried up because they were not stored correctly.
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