Table 2: Literature search overview.

Meditation study overviewSample size, populationIntervention/doseControlLength of baseline, no. of BP readingsRandomized, blindedTherapists’ trainingResultsF/U

Mindfulness [7]70 (normotensive, female posttreatment cancer patients, age ≥18)8 wk. MBSRPassive (waitlist)3 readings taken at 3-min. intervalsNot randomized, NR if blindedClinical psychologist with over 10 yrs. of experienceNo significant difference in BP between MBSR group and control; when patients were analyzed by “higher BP" and “lower BP" groups based on BP readings at week 1, “higher BP" MBSR participants had lower SBP compared to controls at week 8None
Mindfulness [8]121 (African American ninth graders, resting SBP between 50th and 95th percentiles)Life skills training, health education, or Breathing Awareness Meditation (BAM), with 10-min. in-school and at-home sessions every day for 3 mos.None4 readings taken within 10 min. (first reading discarded) over 3 consecutive daysRandomized, single-blindHealth/physical education teachers trained and certified by program instructorsOnly the BAM group showed significant decreases in 24-hour SBP3 mos.
Mindfulness [9]166 (African American ninth graders, resting SBP between 50th and 95th percentiles)Botvin LifeSkills Training or BAM, with 10-min. in-school and at-home sessions every day for 3 mos.Active (health education)3 readings taken within 10 min. (first reading discarded) over 3 consecutive daysRandomized, NR if blindedHealth education teachers trained by program instructorsBAM group showed greatest decreases in SBP, changes in overnight SBP, DBP, and heart rate (significant group differences)None
Mindfulness [10]56 (adults aged 30–60 yrs., 91% Caucasian, BP in the prehypertensive range, 120–139 mm Hg SBP, or 80–89 mm Hg DBP, unmedicated)MBSR for 8 wks.Active (PMR training)3 readings taken at 5-min. intervals, followed by 2 additional measurements within 2 wks.Randomized, single-blindMBSR and PMR therapistsMBSR produced significant decreases in clinic SBP (by 4.9 mm Hg) and DBP (by 1.9 mm Hg)None
TM [11]35 (adolescents with high normal BP aged 15–18 yrs., 34 African Am., 1 Caucasian Am., resting SBP ≥85th and ≤95th percentile)TM, with 15 min meditation sessions twice/day for 2 mos.Active (health education)3 consecutive occasions, length of baseline NRRandomized, NR if blindedNRTM group showed greater decreases in resting SBP and in SBP during acute stressorNone
TM [12]60 (African American adults, aged >20 years; with high normal BP of 130–139/80-85, stage 1 hypertension BP of 140–159/90–99, or stage II hypertension BP of 160–179/100–109)TM for 6–9 mos. (average intervention period of mos.)Active (CVD risk factor prevention education program)3 readings taken at each of 3 consecutive visits (last 2 visits were averaged)Randomized, single-blindCertified instructors from the African American communityBoth groups had significant decreases in BP (TM group by  mm Hg SBP and  mm Hg DBP, control group by SBP and DBP), but only the BP decrease in TM group was associated with corresponding decrease in carotid intima-media thickness)None
TM [13]39 (normotensive Caucasian Am. male adults, mean age of 24.6 yrs.)TM for 4 mos.Active (cognitive-based stress education)BP measured every 4 min. for 20 min.Randomized, single-blindQualified TM instructorTM decreased ambulatory DBP by  mm Hg (  mm Hg in high-compliance subgroup)None
TM [14]298 (university students, BP <140/90 and > 90/60 mm Hg, with 159 in a hypertension risk subgroup for having SBP>130 mm Hg, DBP>85 mm Hg, or other risk factors)TM for 3 mos.Passive3 readings taken at 1-min. intervals (last 2 readings were averaged)Randomized, single-blindResearch staff and TM instructional staffIn the hypertension risk subgroup, TM significantly reduced SBP by 5.0 mm Hg and DBP by 2.8 mm Hg; reductions in overall sample were not significant. TM produced significant improvements in total psychological distress, anxiety, depression, anger/hostility, and coping.None
TM [15]100 (African American adolescents aged yrs., with high normal SBP)TM for 4 mos.Active (health education control with lifestyle education sessions)Readings taken from 6AM–11PM every 20 min. (daytime) and 11PM-6AM every 30 min. (nighttime) over 24 hrs.Randomized, NR if blindedNRTM group showed greater declines in daytime SBP ( ) and DBP ( ) compared to the health education control group4 mos.
TM-based [16]41 (adults aged 22–62 yrs., with essential hypertension, unmedicated, ≥100 mm Hg arterial pressure)SRELAX group received training over 5 wkly. sessions based on TM (including mantra), with 15–20 min meditation sessions twice/dayBoth passive and active (NSRELAX placebo group had same training, no mantra)5 readings taken at 1 min. intervalsRandomized, single-blindExperienced TM instructorBoth SRELAX and NSRELAX modestly decreased BP, with significant decrease only in DBP3 mos.
TM or relaxation [17]127 (hypertensive African Am. adults aged 55–85 yrs., SBP ≤179 mm Hg, DBP 90–104 mm Hg)Transcendental Meditation (TM) or progressive muscle relaxation (PMR), with 1 wk. initial instruction and 1.5 hr. monthly followups for 3 mos.Active (lifestyle modification)4 readings over 1-2 mos.Randomized, single-blindNRTM significantly decreased BP in both women (SBP by 10.4 mm Hg, DBP by 5.9 mm Hg) and men (SBP by 12.7, DBP by 8.1); PMR only decreased DBP significantly in men (by 6.2)3 mos.
TM or relaxation [18]127 (African Am. adults aged 55–85 yrs., with mild hypertension, SBP ≤189 mm Hg, DBP 90–109 mm Hg, final baseline BP ≤179/104 mm Hg)TM or PMR, with 1 wk. initial instruction and 1.5-hr. monthly followups for 3 mos.Active (lifestyle modification)3 readings taken at one visitRandomized, single-blindAfrica Am. instructors qualified to teach either TM or PMRTM decreased SBP by 10.7 mm Hg, DBP by 6.4 mm Hg (both significantly greater decreases than those in PMR)3 mos.
TM or relaxation [19, 20]150 (African Am. adults, mean age of yrs., SBP 140 to 179 mm Hg, DBP 90–109 mm Hg)TM or PMRActive (conventional health education)3 readings taken within 1 hr. at each of 5 sessions over 1 mo.Randomized, single-blindNRTM decreased SBP by 3.1 mm Hg, DBP by 5.7 mm Hg (greatest decrease of all groups); TM decreased use of antihypertensive medication (relative to increases in other groups)1 yr.
TM, mindfulness, or relaxation [21]72 (elderly retirement-age adults, mean age of 81 yrs.)TM, mindfulness training (MF), or mental relaxationPassive3 readings taken at 2-min. intervals (only SBP reported)Randomized, single-blind21 trained instructors (professionals, graduate students, and college seniors)TM decreased SBP by 12.4 mm Hg (greatest decrease of all groups), and survival rate was 100% (compared to the second highest, 87.5% in MF) after 3 yrs.3 yrs.