Since 1970, more than 500 research studies have been con ductedon meditation, according to Robert Roth, a business consultant, teacherof Transcendental Meditation and author of a book on the subject. The most recent study was published in August inthe American Heart Association journal Hypertension. That study by CharlesN. Alexander, a researcher from the Maharishi University of Management inFairfield, Iowa, found that a group of black patients working to reducestress by using transcendental meditation lowered their blood pressure moresignificantly than by using other relaxation techniques or lifestyle modifications. A study published in April by the American Journal of Cardiology found thatsome patients with coronary heart disease improved their tolerance of exerciseafter meditating twice daily. Earlier studies indicated a general physiologicaleffect of meditation including a decline in production of a body chemicalcalled cortisol.
Cortisol helps protect the body's cells and tissues frominflammation and the effects of stress.
But too much cortisol, which isproduced when the body is under stress, weakens the immune system and promotesdiabetes and hypertension. Other studies found an increase in blood flowin the muscles and skin after meditation. During meditation, oxygen consumption decreases,as does heart rate, and blood flow increases, researchers have found. Some physicians prescribe it for their patientswith high blood pressure. One is Phil Lichtenfield, who practices in Encino,Calif., and began meditating in medical school 20 years ago.