This is one of the better-studied claims in the field, and the answer is a careful yes. Pooling seventeen randomized trials of slow breathing (ten breaths a minute or slower, at least five minutes a day, at least three days a week, for at least four weeks), systolic pressure came down by roughly 5.6 mmHg and diastolic by about 3. That is in the range of a single lifestyle change like cutting salt, and well short of medication. The authors call it a reasonable first step for low-risk people who would rather not start a pill, which is a sentence worth reading twice: first step, low risk, rather than a replacement for anything a doctor has prescribed.
The caution comes from the earlier literature. A 2012 review of the breathing-pacing device sold for this purpose found that when the trials sponsored by or involving the manufacturer were removed, the effect disappeared. The 2019 meta-analysis includes non-device trials too, which is part of why it is the one to trust more, but the heterogeneity across studies was high, meaning the trials did not all find the same thing.
What this looks like in practice is the six-breaths-a-minute pattern, done daily, with your numbers checked by someone who can read them. The book's Number on the Screen room covers the waiting-room version; the Notes for Chapter 26 cite the earlier Zou meta-analysis in cardiac patients.
The studies
Chaddha A, Modaff D, Hooper-Lane C, Feldstein DA. Device and non-device-guided slow breathing to reduce blood pressure: a systematic review and meta-analysis. Complementary Therapies in Medicine 45, 2019, 179–184. Read the abstract
- Sample
- 17 RCTs
- Design
- Meta-analysis of randomized trials in hypertensive and prehypertensive adults.
- Found
- Slow breathing lowered systolic pressure by 5.62 mmHg (95% CI 3.38–7.86) and diastolic by 2.97 mmHg.
- Limits
- High heterogeneity; mostly short trials; the authors frame it as a first step for low-risk patients, not a treatment for established disease.
Mahtani KR, Nunan D, Heneghan CJ. Device-guided breathing exercises in the control of human blood pressure: systematic review and meta-analysis. Journal of Hypertension 30(5), 2012, 852–860. Read the abstract
- Sample
- 8 RCTs
- Design
- Systematic review of trials of one pacing device.
- Found
- Short-term use lowered pressure in the pooled result, but five of eight trials were sponsored by or involved the manufacturer; with those removed there was no overall effect.
- Limits
- Longest trial nine weeks; no effect on heart rate or quality of life.
Where this lands in the book
Techniques
Rooms
Two rules, no exceptions
Never practice any technique on this site while you are driving, operating machinery, or doing anything that needs your full attention. The slow ones can make you drowsy, faster than you’d expect. And never practice a breath-hold, bellows breath, or any vigorous breathing in or near water. Read Before you begin for the doctor’s list and the rest.
Verdict scale: Science means trials or meta-analyses with consistent findings; Promising means real trials that are small, few, or unreplicated; Mixed means the studies point both ways; Mechanism means it shows how something works in the body, not that it helps in life. Checked against the published abstracts in October 2026. Not medical advice.