By: Thomas Pickering, MD, DPhil, FRCP, Director of Integrative and Behavioral Cardiology Program
of the Cardiovascular Institute at Mount Sinai School of Medicine, New York.

In this study 127 African-American men and women attending an inner-city hypertension clinic were allocated to one of three groups. The first practiced transcendental meditation (TM) for 20 minutes twice a day, the second used progressive muscular relaxation for the same amount of time, and the third received an educational lifestyle modification program. At the end of three months, the blood pressure in the TM group was lower than in the educational group (by 10/6 mm Hg mm Hg -- systolic/diastolic -- in the women, and 13/8 in the men). Inconsistent changes were seen in the relaxation group. The blood reductions with TM were equally big in people who had high or low levels of stress. In both active treatment groups, the compliance with the program was very high (97% of people in the TM group and 81% in the relaxation group practiced their technique twice a day).

Doctor's comments

This is the most convincing study to date showing that meditation lowers blood pressure. Although earlier studies have made the same claim, one of the criticisms has been that the observed reductions may have been the result of a placebo effect, on the grounds that the subjects in the treatment groups may have had a high expectation of success, which resulted in a transient reduction of pressure at the time of the clinic visit. In this case, however, the authors had the subjects estimate their expectation of success at the start of the study, and it was the same in all three groups. The authors also discounted the placebo effect as an explanation on the grounds that it should have been the same in the two treatment groups, and therefore the reduction of blood pressure should have been the same, which it clearly was not. Why does this matter? The answer is that placebo effects don't last long, and the reduction of pressure tends to be limited to the clinic setting. What this study does not tell us is what happens to the blood pressure during the stresses of everyday life. Nonetheless, the findings are very encouraging, and the size of the blood pressure reduction comparable to the changes produced by medication.

Where it was published