Effectiveness of Alternative Nostril Breathing on Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Introduction: Hypertension, a significant risk factor for cardiovascular disease, has a high prevalence rate globally. While drug use is the most common approach, lifestyle improvements are crucial. Recently, there has been a notable upsurge of interest in various breathing methods, including device-induced breathing techniques like Resperate. However, the reliance on a device for these techniques has prompted the popularity of alternative breathing methods that can be performed without any external devices. One such method that has gained significant attention is alternative nostril breathing, which serves as an alternative medical treatment known for its effectiveness in reducing blood pressure. Therefore, this study aimed to systematically investigate the therapeutic effects of alternate nostril breathing.

Methods: We selected 16 articles published in English, Korean, and Chinese databases, of which 14 met the eligibility criteria, and a systematic literature review was conducted. A meta-analysis was conducted on six qualified studies. Meta and sensitivity analyses were conducted using a random effects model of six randomized clinical trials (RCTs).

Results: Results of alternative nostril breathing (ANB) on 1,377 participants have been reported based on the effects of systolic and diastolic blood pressure (SBP and DBP). Both the lone ANB and combined yoga programs resulted in significant reductions in SBP and DBP. Meta-analysis of the 6 trials with 525 participants demonstrated that ANB was better in reducing SBP than that of the control group (nonintervention or placebo) (mean difference [MD]: -7.16, 95% confidence interval [CI]: -7.86 to -6.45, I2: 93%). Moreover, ANB was better in reducing DBP than that of the control group (nonintervention or placebo) (MD: -5.16, 95% CI: -5.89 to -4.44, I2: 87%).

Conclusion: The results of the study are valid; however, attention is needed when interpreting the results because the heterogeneity exceeds 75%. A systematic review of 14 studies found that ANB can improve cardiovascular indicators, such as SBP and DBP, as well as non-cardiovascular factors, such as fatigue, intraocular pressure, and memory. However, the review noted that implementing double blinding in studies on yoga breathing intervention is difficult, and most studies were not double-blinded, suggesting the need for high-quality RCTs in the future.