Renin, Cortisol, and Aldosterone During Transcendental Meditation

Transcendental meditation (TM) did not produce a unique physiological state of reduced stress or sympathetic activity. During TM, plasma renin activity increased slightly (14%), while cortisol decreased progressively in both meditators and controls. Aldosterone and lactate did not change. Meditators showed no increase in cortisol between initial samples, unlike controls, suggesting they may be less responsive to acute stress. The findings do not support the idea that TM induces a special relaxation state.

Study at a glance

Abstract

The effects of transcendental meditation (TM) on plasma renin activity (PRA) and plasma concentrations of aldosterone, cortisol, and lactate were studied by measuring these variables before, during, and after 20--30 min of meditation. Subjects, who rested quietly rather than meditating, served as controls. There were no differences in the basal values for these variables between meditators and controls, but controls, in contrast to meditators, showed a significant increase in cortisol between the first (A) and second (B) samples of the control period. PRA increased slightly (14%) but significantly (p less than 0.03) during TM, but not during quiet rest in controls. Cortisol decreased progressively (after sample B) throughout the experiment to the same degree in both groups. Aldosterone and lactate did not change. The data do not support the hypothesis that TM induces a unique state characterized by decreased sympathetic activity or release from stress, but do suggest that meditators may be less responsive to an acute stress.