A new study conducted by researchers affiliated with Lanzhou University in China and the University of Southern California explored several subgroup analyses to investigate the effect of Transcendental Meditation on blood pressure.
Evidence from previous randomized controlled trials and systematic reviews has demonstrated a positive association between hypertension and the Transcendental Meditation (TM) technique. However, other trials and reviews showed the effect of TM on blood pressure was unclear but did not use subgroup analysis to rigorously investigate this relationship. The American Heart Association has stated that TM is potentially beneficial but did not give a standard indication.
Review and meta-analysis
In the study published in Journal of Human Hypertension, Medline, Embase, Cochrane Library, Web of Science and Chinese BioMedical Literature Database were searched through August 2014. 
Randomized controlled trials of TM as a primary intervention for blood pressure were included. Two reviewers independently used the Cochrane Collaboration’s quality assessment tool to assess each study’s quality.
Twelve studies with 996 participants indicated an approximate reduction of systolic and diastolic BP of −4.26 mm Hg (95% CI=−6.06, −2.23) and −2.33 mm Hg (95% CI=−3.70, −0.97), respectively, in Transcendental Meditation groups compared with control groups.
Results
Results from subgroup analysis suggested that TM had a greater effect on systolic blood pressure among older participants, those with higher initial blood pressure levels, and women, respectively. In terms of diastolic blood pressure, it appears that TM might be more efficient in a short-term intervention and with individuals experiencing higher blood pressure levels.
Academic reference:
Z Bai, J Chang, C Chen, P Li, K Yang and I Chi. (2015). “Investigating the effect of transcendental meditation on blood pressure: a systematic review and meta-analysis”, Journal of Human Hypertension.
