The Buteyko breathing method is based on the assumption that many health problems are caused by hyperventilation.
By training people to breath less, it claims that (amongst other symptoms) asthma can be cured, or at least improved.
Is there any evidence that supports this case?
Short answer: The method may or may not completely cure asthma but may be used to reduce dependency on an inhaler. It is not proven to work for all patients.
It has wider acceptance in Australia and UK and more opposition in the USA from what I've found so far. See the last bit of my post on that.
Proponents of the method may know that
British Guideline on the Management of Asthma - A national clinical guideline from the NHS and British Thoracic Society in 2008 (See PDF pg 35) gave it the following recommendation
The Buteyko breathing technique specifi cally focuses on control of hyperventilation and any ensuing hypocapnia. Four clinical trials suggest benefi ts in terms of reduced symptoms and bronchodilator usage but no effect on lung function.
Category B
Buteyko breathing technique may be considered to help patients to control the symptoms of asthma.
In April 2009, a course to train nurses how to teach the Buteyko Breathing Technique to people with asthma was launched by Coventry University and the Buteyko Breathing Association. This shows a more mainstream acceptance of this technique in the UK.
There have been at least 8 clinical trials as listed on this page. Notably none are in the USA and none are very large groups (none more than 69 subjects). This page also links to abstracts of each of the trials - I've summarized conclusions below.
ENGLAND 2009 (32 subjects, 5 weeks)
By teaching patients to reduce hypernoea of breathing (the rate & depth), BBT may reduce asthma symptoms and improve exercise tolerance and control.
CANADA 2008 (56 subjects)
Six months after completion of the interventions, a large majority of subjects in each group displayed control of their asthma with the additional benefit of reduction in inhaled corticosteroid use in the Buteyko group
NEW ZEALAND 2006 (8 subjects)
Conclusions: children’s decreased use of reliever medication mirror adults and warrant further studies.
AUSTRALIA 2006 (23 subjects)
Conclusion: breathing techniques useful in management of asthma.
The process of routine and as required exercises may reinforce a message of relaxation and self efficacy and provide a deferral strategy for reliever use.
ENGLAND 2003 (23 subjects)
Conclusion: Buteyko can reduce bronchodilator use and improve symptoms. Buteyko may be worth trying in patients who are sympathetic to the ethos and are willing to commit the time required.
Choice of control is difficult, maintaining blindness is a problem. Limited follow up visits to one for each group to remain comparable, but some subjects would have liked more. Success or failure relies heavily on patient/practitioner relationship.
Paitents need to be motivated, so the success rate of a formal trial may be less than that seen in everyday practice, and since patients did not chose the Buteyko couse, and because they are not paying, they may be less committed to seeing it through.
NEW ZEALAND 2003 (17 subjects)
At six months Buteyko Group (n=17) or control (n=17) asthma education and relaxation.
• Reliever medication decreased by 85% in Buteyko group, by 37% in control group.
• Inhaled corticosteroids decreased by 50% in Buteyko group, unchanged in control.
AUSTRALIA 2000
Conclusions: Buteyko may be effective in improving quality of life and reducing inhaled reliever medication in patients with asthma –warrants further investigation.
AUSTRALIA 1998 (19 subjects)
At three months Buteyko Group achieved
• Reliever medication decreased by 90%. Significantly more than control (P=0.002)
• Trend towards reduction of inhaled corticosteroids
So now on to the opposition, the Wikipedia article you've linked has the U.S. National Heart, Lung, and Blood Institute asthma guideline concluding this summary
The Expert Panel concludes there is insufficient evidence to suggest that breathing techniques provide clinical benefit to patients who have asthma. Controlled studies have been conducted with breathing exercises (Holloway and Ram 2004), inspiratory muscle training (Ram et al. 2003; Weiner et al. 2002), and Buteyko breathing (Cooper et al. 2003) (raising blood PCO2 through hypoventilation).
but Cooper's actual study was on Buteyko v Pranayam and notes
Symptoms remained relatively stable in the PCLE (to mimic Pranayam) and placebo groups but were reduced in the Buteyko group
and concludes that inhaler use may be reduced
CONCLUSION: The Buteyko breathing technique can improve symptoms and reduce bronchodilator use but does not appear to change bronchial responsiveness or lung function in patients with asthma. No benefit was shown for the Pink City Lung Exerciser.
From what I've seen on some forums, the US opposition is a conspiracy angle, that this will reduce sales for large pharmaceuticals.
My answer is based on the article Buteyko Breathing Technique – Nothing to Hyperventilate About in Science-Based Medicine ("SBM"). The site claims:
SBM is a completely independent endeavor. We receive no industry funding and have no financial conflicts of interest. Our only goal is to promote high standards of science in medicine.
This article reviews all the published research on the Buteyko Breathing Technique. In particular, it discusses the evidence presented in the other answer to this question by @JoseK.
In that answer, @JoseK quotes the British Thoracic Society’s Guidelines, but changes their "Grade B" to "Category B" without explanation. Grade B means the research is not of the highest quality. The correct quote is:
The Buteyko breathing technique specifically focuses on control of hyperventilation and any ensuing hypocapnia. Four clinical trials suggest benefits in terms of reduced symptoms and bronchodilator usage but no effect on lung function. Buteyko breathing technique may be considered to help patients to control the symptoms of asthma. Grade B
(Emphasis mine)
The Science-Based Medicine article states:
[while] the BTS authors were overly generous in ranking the four evaluated articles as 1+ level of evidence (meaning a well conducted meta-analysis, systematic review, or RCTs with a low risk of bias), their conclusions are not unreasonable within the framework of Evidence Based Medicine.
The Science-Based Medicine article further states (paraphrasing the article):
These studies can be found wanting on nearly every point outlined in John Ioannidis’ famous essay Why Most Published Research Findings Are False. All the evidence is weak when viewed through the lens of Evidence Based Medicine. Upon our review at Science Based Medicine, the Buteyko literature loses much of its remaining impact.
SMB's Summary (also paraphrased):
Buteyko starts from an erroneous observation, uses flawed logic, lacks prior plausibility, forsakes scientific validation, and promotes the technique as a virtual panacea. Buteyko may have found a small medical niche where the technique may have some limited utility - the symptomatic relief of mild asthma symptoms.
If however, you are looking for the Buteyko Breathing Technique to cure your asthma [my edit: or actually improve lung function], I wouldn't hold my breath.
I believe @JoseK erred in the other answer by stating:
Short answer: The method may or may not completely cure asthma.
There is no evidence whatsoever that the method can completely cure asthma, and all available evidence points to the opposite conclusion: that the Buteyko Breathing Technique does not cure asthma. From a skeptical point of view, this has to be the more reasonable conclusion.
The Buteyko Breathing Technique is one of several breathing exercises promoted to help asthma.
Cochrane publishes systematic reviews of health literature to inform health professionals about the evidence. They have done four such reviews of breathing exercises, two related to asthma:
Both take a critical and methodical look at a number of studies, including many with apparently positive results, and draw similar conclusions:
For children:
We could draw no reliable conclusions concerning the use of breathing exercises for children with asthma in clinical practice. The breathing exercises were part of a more comprehensive package of care, and could not be assessed on their own. Moreover, there were methodological differences among the three small included studies and poor reporting of methodological aspects and results in most of the included studies.
For adults:
Even though individual trials reported positive effects of breathing exercises, no reliable conclusions could be drawn concerning the use of breathing exercises for asthma in clinical practice. This was a result of methodological differences among the included studies and poor reporting of methodological aspects in most of the included studies. However, trends for improvement are encouraging, and further studies including full descriptions of treatment methods and outcome measurements are required.
It appears that, as of 2013, there is insufficient evidence to recommend breathing exercises like the Buteyko method, but neither has there been sufficient evidence to rule out that it might help.
