Individuals with prehypertension will probably develop hypertension unless lifestyle is improved. Prehypertension as well as hypertension (high blood pressure) elevate the risk of stroke, heart attack, and heart failure.
High blood pressure is defined as 140/90 mmHg, and prehypertension as BP 120-139/80-89 mmHg.
The study looked at how hatha yoga affected blood pressure in 60 otherwise healthy individuals with prehypertension. The individuals were divided into 2 groups of 30 to determine how 3 months of yoga together with conventional lifestyle changes affected 24 hour ambulatory blood pressure versus conventional lifestyle changes alone.
Yoga included breath control (pranayam), stretching exercises (asanas) and meditation. A yoga instructor taught for 1 month and then the perticipants subsequently continued yoga practice for an hour a day at home for the other 2 months. Conventional lifestyle changes were comprised of diet, smoking cessation and moderate aerobic exercise.
The participants’ average age in the yoga group was 56 years and in the control group it was 52 years. There were 14 men and 16 women in the yoga group, and there were 13 men and 17 women in the control group. At the start of the study, the 24 hour average blood pressure in the yoga group was 130/80 mmHg and in the control group it was 127/80 mmHg.
Both 24 hour diastolic blood pressure and night diastolic blood pressure decreased by about 4.5 mmHg in the yoga group and 24 hour average arterial pressure decreased by about 4.9 mmHg. There were no significant change in blood pressure in the control group.
Despite the modest reduction in blood pressure, it could be significant as even a 2 mmHg diastolic blood pressure decrease has the potential to reduce coronary heart disease risk by 6% and transient ischaemic attack and stroke risk by 15%.
The exact mechanism isn’t clear from the study how yoga reduces blood pressure but it has been suggested that the sympathetic drive might be decrease from yoga. The results indicate that a combination of all 3 yoga components (pranayam, asanas and meditation) helps but the study is not able to pinpoint any individual contribution.
The research suggests that individuals with prehypertension should be advised to practice hatha yoga for one hour daily. It could prevent the development of hypertension and also give a sense of well-being.