12-weeks of Slow Breathing Exercises Reduces Blood Pressure among Healthy Normotensive Subjects

Slow breathing exercises are a key component to many mind-body practices used for stress reduction and modulation of autonomic tone, and it has been shown to reduce blood pressure acutely. Long-term effects on blood pressure and autonomic tone are not well documented. We studied 95 healthy participants (41±4 years, 76% female) who performed slow breathing exercises for 12 weeks and examined the effect of slow breathing on systolic blood pressure, diastolic blood pressure, and autonomic tone. At baseline average BP was 105±11/67±8 mmHg. Among the 11 participants with elevated blood pressure, BP was 126±11.0/ 80±5 mmHg. Our comparison group, that received no intervention, consisted of 30 participants with baseline mean BP 125±19/ 71±10 mmHg. SBP and DBP decreased significantly (−2.4±7.3 and -1.6±5.5 mmHg, respectively) at 12 weeks for all participants who practiced slow breathing. The comparison group showed no significant changes in blood pressure. Blood pressure reduced further among slow breathing participants with baseline SBP over 120mmHg and/or DBP over 90mmHg (−10.3±7.9 and -3.8±5.5 mmHg, respectively). In our regression model, baseline SBP was associated with further decreases in SBP from baseline to 12 weeks. No significant changes were observed in spectral analyses from baseline to 12 weeks or correlations between spectral analyses in blood pressure. In conclusion, 12-weeks of slow breathing exercises resulted in a significant reduction of blood pressure in the absence of significant changes in autonomic tone as measured by spectral analyses. Further research into the mechanisms and effectiveness of slow breathing on cardiovascular health is needed.