Take a SHALLOW breath: can we improve asthma through breathwork?

Could we be breathing better? All of us are familiar with the idea of taking a deep breath. We’re told to do it when stressed, anxious, angry, or overwhelmed. I have even written a previous blog post about the science behind deep breathing and the mechanisms by which it helps calm the body (spoiler: it’s the extended exhale that matters, not the inhale). Much more rarely, however, have we been told to take a shallow breath. A number of research studies out there seem to be highlighting the benefits of shallow nasal breathing, so let’s delve into the research for a more comprehensive understanding.

Why is Nasal Breathing Better?

The Short:

Our bodies are built to breathe through our noses, and the production of nitric oxide is stimulated when we inhale and exhale through our nose.

The Simple: Unlike the mouth, breathing through the nose filters, humidifies, and warms air. When we breathe through our nose, we are helping clear our air pathways of dust, allergens, and bacteria. That’s why breathing through our nose instead of our mouth is the first defense against infections like covid19. If that wasn’t enough to make you think twice about your breathing, mouth breathing is also associated with more throat infections and cases of gingivitis¹.

The Science: Nitric oxide plays a key role in the beneficial effects that come from nasal breathing. It is produced in our paranasal sinuses and its production is stimulated by nasal breathing. When we breathe through our nose, our nose produces nitric oxide. The people that breathe through their mouth have been shown to have less nitric oxide in their airways². Here’s why nitric oxide is important: it stimulates mucus secretion which increases removal of dust and viral particles from our airways, it produces antimicrobial effects against bacteria and viruses, and it can actually help inactivate viruses by modifying their ability to reproduce³. Nitric oxide also helps to deliver more oxygen to tissues in our body, so when we are breathing through our noses, we are actually helping send oxygen to faraway tissues in our body.

Why are “Mouth Breathers” so common right now?

The prolonged use of face masks during the covid-19 pandemic may actually be responsible for converting some of us from nose breathers to mouth breathers. Studies have noted wearing facemasks can actually alter our normal breathing pattern⁴ ⁵. That said, there’s not enough research out there on this topic. It remains uncertain how many of us are actually mouth breathers, though pre-pandemic studies have reported numbers like 26% to 56% ⁶ ⁷ and there is a chance that it's higher following long term mask usage. Most of the studies that look at mouth breathing focus on children populations and state potential causes of mouth breathing to be adenoid issues, thumb sucking, chronic allergies, deviated nasal septums, excessive pacifier use, and nasal polyps ⁸. There just isn’t enough research out there on adult populations to draw any sort of conclusion as to why mouth breathing continues into adulthood, but regardless, we know it happens.

Does Nasal Breathing Improve Asthma?

An association between asthma and mouth breathing has been shown in the research with children, adolescents, and adults⁹, but there’s not enough evidence out there to clearly understand the link between them. That said, there has been research about improving asthma by switching from mouth breathing to nasal breathing, so we can see that the way we breathe has an important role in asthma.

One study found that shallow nasal breathing led people to use their inhalers less, and that using their inhaler less did not make their asthma worse¹⁰.

shallow nasal breathing led people to use their inhalers less, and using their inhaler less did not make their asthma worse¹⁰.

So in other words, nasal breathing helped people use their inhalers less and their asthma did not get worse from not using their inhaler regularly. The tricky part: Even though they were using their inhaler less, it wasn’t because their airways improved or their lung inflammation went down. There wasn’t a physiological improvement due to the breathing exercises. The researchers suggest that maybe participants were using their inhalers less because they didn’t need to inhale their full dose of corticosteroids anyway to manage their asthma, and that a lower dose is all that would be required to help their asthmatic needs. Either way, nasal breathing seems to have made people feel that their asthma is more manageable.

A study in 2008 took a different approach: it researched whether forced mouth breathing would decrease lung function in people with mild asthma. Lung function actually did decrease over time on days where participants were mouth breathing, and coughing and wheezing were more likely to happen, too¹¹.

Buteyko Breathing Method (AKA slow and shallow breathing)

The Buteyko method is a form of nasal breathing that is based on the premise that slow and shallow nose breathing improves asthma by inducing hypoventilation and raising blood carbon dioxide levels¹². Buteyko breathing makes use of control pause exercises and breath holding exercises to improve breathing. The idea behind it is that asthma is related to hyperventilation that causes chest tightening (bronchospasm) and mucus build up (accumulation of secretion). The goal of Buteyko breathing then is to improve these two things by normalizing blood carbon dioxide levels through smaller inhalation and exhalations (called reduced-volume breathing).

Here’s an example of a control pause exercise that’s used in Buteyko breathing to evaluate breathing health. The below exercise is adapted from a study at Mansura University¹³.

​1. Sit upright with good posture.

2. Take a small breath in (2 s) and a small breath out (3 s). Hold nose after the “out” breath, with empty lungs but not too empty.

​3. Count how many seconds you comfortably last before the need to breathe in again.

4. Release the nose and breathe in through it. This breath should be no greater than the breath prior to taking measurement. Pausing too long could cause you to take too big of a breath after the measurement.

Here’s an example of a breath holding exercise that’s used in Buteyko breathing, adapted from the same study.

1. Place a finger under your nose, just above your top lip, close enough to your nostril that you can feel airflow.

2. Breathe air slightly into tip of the nostril. Imagine the finger is a feather that you don’t want to move when you exhale.

3. The more warm air you can feel, the bigger you are breathing. Concentrate on calming your breath to reduce the amount of warm air on your finger.

4. Maintain this shallow nasal breathing for 4 minutes.

Here’s how you’d put them together, adapted from the same study.

1. Reduce breathing for 4 min. Wait 2 min and take Control pause. Reduce breathing for 4 min. Wait 2 min and take Control pause.

The Mansura University study found that these Buteyko breathing exercises (practiced daily for four weeks) improved asthmatic symptoms, peak expiratory flow rate, and improved performance on a pulmonary function test. Another study found that a group of participants who had been trained in Buteyko breathing saw an 85% reduction in rescue inhaler use and a 50% reduction in regular inhaled steroid use even at 6 month follow up¹⁴.

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Here's the "Too Long; Didn't Read" of it:

• Nasal breathing filters, humidifies, and warms air. It clears our air pathways of dust, allergens, and bacteria and sends oxygen to tissue in our body. Mouth breathing does NOT have these positive effects.
  

• We can become better nasal breathers through practice.
  

• Nasal breathing improves asthma and sleep quality.
  

• The Buteyko Breathing method has been shown to significantly improve scores on lung function tests, decrease asthmatic symptoms, and improve physical performance.
  

• More studies in this area are needed, but for now the outcomes look promising.

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References

Abreu, R. R., Rocha, R. L., Lamounier, J. A., & Guerra, Â. F. M. (2008). Prevalence of mouth breathing among children. Jornal de Pediatria, 84, 467-470.

Akturk, E. S., Aydin, I., & Seker, E. D. (2022). The effects of mask usage during the COVID-19 pandemic on temporomandibular joint. Clinical Oral Investigations: preprint.

Araújo, B. C. L., de Magalhães Simões, S., de Gois-Santos, V. T., & Martins-Filho, P. R. S. (2020). Association between mouth breathing and asthma: a systematic review and meta-analysis. Current Allergy and Asthma Reports, 20(7), 1-10.

Bruton, A., & Thomas, M. (2011). The role of breathing training in asthma management. Current opinion in allergy and clinical immunology, 11(1), 53-57.

Fricker, J., Kharbanda, O. P., & Dando, J. (2013). Orthodontic diagnosis and treatment in the mixed dentition. In Handbook of Pediatric Dentistry (pp. 409-445).

Hallani, M., Wheatley, J. R., & Amis, T. C. (2008). Enforced mouth breathing decreases lung function in mild asthmatics. Respirology, 13(4), 553-558.

Martel J, Ko YF, Young JD, Ojcius DM. Could nasal nitric oxide help to mitigate the severity of COVID-19? Microbes Infect. 2020 May-Jun;22(4-5):168-171. doi: 10.1016/j.micinf.2020.05.002.

Martins, D. L. L., Lima, L. F. S. C., de Farias Sales, V. S., Demeda, V. F., da Silva, A. L. O., de Oliveira, Â. R. S., & Lima, S. B. F. (2014). The mouth breathing syndrome: prevalence, causes, consequences and treatments. A literature review. Journal of Surgical and Clinical Research, 5(1), 47-55.

McHugh, P., Aitcheson, F., Duncan, B., & Houghton, F. (2003). Buteyko Breathing Technique for asthma: an effective intervention. Journal of the New Zealand Medical Association.

Mohamed, E. M. H., ELmetwaly, A. A. M., & Ibrahim, A. M. (2018). Buteyko breathing technique: a golden cure for asthma. American Journal of Nursing, 6(6), 616-624.

Opat, A. J., Cohen, M. M., Bailey, M. J., & Abramson, M. J. (2000). A clinical trial of the Buteyko breathing technique in asthma as taught by a video. Journal of Asthma, 37(7), 557-564.

Slader, C. A., Reddel, H. K., Spencer, L. M., Belousova, E. G., Armour, C. L., Bosnic-Anticevich, S. Z., ... & Jenkins, C. R. (2006). Double blind randomised controlled trial of two different breathing techniques in the management of asthma. Thorax, 61(8), 651-656.

Törnberg, D. C. F., Marteus, H., Schedin, U., Alving, K., Lundberg, J. O. N., & Weitzberg, E. (2002). Nasal and oral contribution to inhaled and exhaled nitric oxide: a study in tracheotomized patients. European Respiratory Journal, 19(5), 859-864.

Triana, B. E. G., Ali, A. H., & León, I. G. (2016). Mouth breathing and its relationship to some oral and medical conditions: physiopathological mechanisms involved. Revista Habanera de Ciencias Médicas, 15(2), 200-212.

Verma, S. Mouth Mask: A Blessing Or A Curse For Oral Health. Journal of Prosthodontics Dentistry.