Research Review Finds Yoga Beneficial in Reducing Hypertension

Hypertension, or high blood pressure, remains the most common reason for office visits to physicians for non-pregnant adults in the United States. Some 50 million Americans are believed to have hypertension. Despite its prevalence and the complications associated with it, control of the disease is far from adequate. As a result, hypertension will likely remain the most common risk factor for stroke, heart failure, and kidney disease for years to come.

At the same time, some 42 percent of Americans have used complementary and alternative medicine (CAM) approaches to meet their health care needs, spending more out-of-pocket for CAM than the amount projected for expenditures in 1997 for all U.S. physician services. Nearly three million people are estimated to have tried mind-body techniques to treat their hypertension; approximately eight percent of the hypertensive population.

Mind-Body medicine, one of five major branches of CAM therapeutics, uses behavioral techniques to augment the mind's capacity to affect bodily function and symptoms, utilizing varied approaches such as meditation, prayer, mental healing, and therapies that use creative outlets such as art, music, or dance. The 2002 National Health Interview Survey (NHIS) found nearly 30 million users of relaxation techniques including meditation and yoga, and 10 million users of yoga therapies. One-fourth of those who used mind-body therapies rated them “very helpful.”

The Study
There has been little quality research to discriminate between positive anecdotal evidence, marketing schemes, and practices that are consistently effective and safe. As a result, a team of researchers conducted a systematic review aims to assess the efficacy of mind-body therapies (MBT) versus placebo or active control in the treatment of hypertension. The main outcome measures include change in systolic and diastolic blood pressure pre- and post-intervention period.

The team reviewed randomized, or quasi-randomized, controlled trials comparing mind-body techniques (meditation, yoga, and guided imagery) alone or in combination with conventional treatment to conventional treatment alone or no intervention/waiting list control. Relevant trials were identified in the register of trials maintained by the Cochrane Complementary Medicine Field Registry, The Cochrane Central Register of Controlled Trials, Medline, EMBASE, PsycInfo, and CINAHL.

Mind-Body Therapies (MBTs)
Participants in these trials were men and non-pregnant women, greater than 18 years of age with hypertension defined as a systolic blood pressure of >140 mm Hg and/or diastolic blood pressure >90 mm Hg. (Normal is defined as systolic >140 and/or diastolic >90 mmHg). The types of intervention undertaken by the study participants were mind-body techniques with the greatest rates of utilization (>3.5 percent prevalence of use in the general population) being meditation, yoga, and guided imagery techniques. A description of each follows: