Is Yoga Efficacious in Asthma?

Almost every health professional has been told by a patient that standard asthma treatment produces undesirable side effects, and that a better replacement exists in one or more forms of alternative medicine. Yoga is regarded as a form of mind-body practice and is the sixth most commonly form of complementary and alternative medicine used by adults in the USA. It is also practised by children.1 There are many forms or styles of yoga from the traditional Hatha yoga to Ashtanga, Bikram, and many more. A number of different postures with different breathing techniques, meditation or relaxation are combined in the different forms of yoga. Yoga is said to produce emotional balance; for asthma, it is claimed that yoga "reduces psychological overactivity, emotional instability, the number of asthma attacks, enhances lung function and (reduces) airway hyperresponsiveness."2

The methods used by the authors of the 2011 review2 were not unlike those used when compiling reports for the Cochrane Database. All papers that might seem relevant were identified through different search engines. Printed copies were obtained, and the articles analyzed independently by the two authors. From a total of 276 papers, 61 were identified as worthy of further analysis. There were 27 clinical trials. The authors pre-determined their criteria for inclusion, and 7 papers totalling 445 pages met that standard. Since the studies were heterogeneous in many different ways, the review authors described each study individually. Four of the trials suggested that Yoga is effective for chronic asthma, whereas three RCTs showed no benefit, compared with controls. It is important to note that the heterogeneity applied to the type of patients studied, their asthma (from mild to severe), outcome measures, and the types of yoga used.

The control groups received a wide variety of different interventions or none, such as "sham intervention, relaxation exercises, group discussion, and cognitive behavioral therapy-like exercises". There were no measures of cost effectiveness, nor did any of the studies look at long-term effectiveness. Considering the problems in reviewing these studies, it is worth including the authors' recommendation that "future studies of yoga should be in line with accepted standards of trial design and reporting . . . in particular, studies should be of adequate sample size based on power calculations, use validated outcome measures, control for nonspecific effects, and minimize other threats to internal and external validity. Reporting of these studies should be such that the investigations can be independently replicated." The authors concluded that "mainly due to the low number and the often low quality of the trial data, the evidence that yoga alleviates asthma is unconvincing. Future research seems warranted."

A 2013 Cochrane review of 13 studies involving 906 adults with mild to moderate asthma found no evidence to support the efficacy of yoga in the treatment of asthma.3 A 2014 systematic review and meta-analysis of randomized controlled trials that involved 824 adults with asthma also found no evidence that yoga as an intervention was helpful in asthma.4 The reviewers suggested that while yoga could not be considered a routine intervention, it should be regarded as an “ancillary intervention or alternate to breathing exercise for asthma patients”.

Unfortunately, too many of the interventions that are said to be both safe and effective are supported by very poor evidence. Yoga may be useful in asthma but at present, it must be used along with conventional treatment, specifically ICS.  It would be risky to use yoga as the only approach when treating a patient with asthma. The asthma educator should advise patients that while yoga will be helpful as a form of exercise, in reducing stress, in relieving anxiety and depression,  it cannot replace asthmamedication and it should be done under the guidance and supervision of a well-trained instructor.

References

  1. National Institute of Health. Yoga for health. https://nccih.nih.gov/sites/nccam.nih.gov/files/Get_The_Facts_Yoga_for_Health_06-04-2013%20%282%29.pdf Retrieved 28 January 2016.
  2. Posadzki P, Ernst E. Yoga for asthma? A systematic review of randomized clinical trials. J Asthma. 2011 Aug; 48 (6):632-9.
  3. http://www.cochrane.org/CD001277/AIRWAYS_breathing-exercises-for-asthma
  4. Cramer H, Posadzki P et al. Yoga for asthma: a systematic review and meta-analysis. Ann Allergy Asthma Immunol. 2014 Jun;112(6):503-510.e5. doi: 10.1016/j.anai.2014.03.014.