In a study of a contemplation meditation and breathing techniques
in the treatment of pharmacologically untreated hypertension,
office systolic pressure decreased by 15 mm Hg in the treatment
group with no change noted in the control group [69]. The study
utilized a very intensive intervention which included 40 min of meditation
two times per day for 8 weeks. A limitation of this and many
controlled studies on meditation is the potential effect of placebo, as
no validated “sham meditation technique” exists.