Here is a summary of five published studies related to breathing rates (or minute ventilation expressed in liters of air per one minute) in asthmatics at rest (when they do not experience problems with asthma).
*One row corresponds to one medical study/publication
Condition Ventilation Number of patients References
Norm 6 l/min - Medical textbooks
Asthma 13 (±2) l/min 16 Chalupa et al, 2004
Asthma 15 l/min 8 Johnson et al, 1995
Asthma 14 (±6) l/min 39 Bowler et al, 1998
Asthma 13 (±4) l/min 17 Kassabian et al, 1982
Asthma 12 l/min 101 McFadden & Lyons, 1968
References (in the same order)
Chalupa DC, Morrow PE, Oberdörster G, Utell MJ, Frampton MW, Ultrafine particle deposition in subjects with asthma, Environmental Health Perspectives 2004 Jun; 112(8): p.879-882.
Johnson BD, Scanlon PD, Beck KC, Regulation of ventilatory capacity during exercise in asthmatics, J Appl Physiol. 1995 Sep; 79(3): p. 892-901.
Bowler SD, Green A, Mitchell CA, Buteyko breathing techniques in asthma: a blinded randomised controlled trial, Med J of Australia 1998; 169: p. 575-578.
Kassabian J, Miller KD, Lavietes MH, Respiratory center output and ventilatory timing in patients with acute airway (asthma) and alveolar (pneumonia) disease, Chest 1982 May; 81(5): p.536-543.
McFadden ER & Lyons HA, Arterial-blood gases in asthma, The New Engl J of Med 1968 May 9, 278 (19): 1027-1032.
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In fact, there is no a single publication that found a single asthmatic who breathes normally. They all breathe heavy 24/7 (except just before the death, when respiratory failure can lead to very low minute ventilation numbers).
What are the effects of heavy breathing?
While most people believe in a myth that breathing more improves oxygenation of the human body, our arterial blood is 98% saturated with oxygen during miniscule normal breathing. Hence, the main effect of hyperventilation is that our lungs and other cells become CO2-deficient. Do we need CO2?
Clinical Science published an article in 1968 titled The mechanism of bronchoconstriction due to hypocapnia in man ("hypocapnia" means abnormally low CO2 concentrations). In the article, Dr. Sterling explained that CO2 deficiency causes an excited state of the cholinergic nerve. Since this nerve is responsible for the state of the smooth muscles in bronchi, its excited state leads to the constriction of air passages. Hence, when we over-breathe, our air passages become constricted.
What about modern textbooks on physiology? One states, "Agents that tend to dilate airways include increased PaCO2 (hypoventilation or inspired CO2)," (p.545, Straub, 1998). This textbook directly claims that slowing down breathing (hypoventilation) or increased CO2 level dilates airways. Moreover, CO2 is suggested as the chief chemical substance that promotes this effect.
What about the asthma-ventilation connection? Russian physiologist Dr. Buteyko, MD proposed this link in the 1950's (his first official publication was published in 1964), when he discovered the central role of overbreathing in the development and degree of asthma. (He and his colleagues also found that asthma patients got immediate relief from their asthma attack symptoms, if they practiced reduced breathing or breathing less).
Dr. Herxheimer independently suggested that low CO2 was the cause of bronchial asthma in 1946 and 1952 (Herxheimer, 1946; 1952).
How do asthma and asthma attacks develop?
Let us consider the mechanism suggested by Dr. Buteyko. Low CO2 values in the bronchi cause chronic constriction of airways (that happens in all people). In addition to this direct effect, chronic hyperventilation makes immune reactions abnormal. The immune system of asthmatics becomes too sensitive in relation to intruders from outside (coming with air or food), but weakens the responses to various pathogens, like viruses and bacteria. (That makes sense since hyperventilation is a defensive reaction and a part of the fight-or-flight response. Hyperventilation then should mean a state of increased alertness and emergency for the whole organism, the immune system included.)
The immune system of asthmatics becomes hypersensitive and seemingly innocent events like breathing cold air or inhaling dust particles can trigger an inflammatory response in bronchi, excessive production of mucus, a sense of anxiety or panic, more hyperventilation, and further constrictions of airways. This is a genetic component of asthma.
As a result, enlarged must cells and mucus make air passages narrower (or even block some of them) creating a feeling of suffocation and causing asthma attacks. During an attack, an asthmatic may try to clear the mucus by coughing it out, but that further reduces CO2 concentrations in the lungs and makes air passages narrower.
Clearly, asthma is the disease of heavy breathers. Asthma symptoms are possible only when one breathes at least 3-4 times the norm. Asthmatics have big breathing at rest and even bigger and heavier during acute stages. If an asthmatic slows down and normalizes their breathing, so that they breathe 6 l/min, they would not experience their symptoms and medication would be unnecessary. Moreover, there is a simple breathing exercise how to stop an asthma attacks in 2- 3minutes by ... breathing less. (Search the web for details.)
The medical self-oxygenation therapy (how to increase body oxygenation and CO2 stores by breathing less) is practiced by hundreds of health and medical practitioners in Russia and other countries. It proved its efficiency for asthma in many trials. The therapy is known as the Buteyko breathing method.
Resources
Asthma and Allergies - Review and solutions
Stop Acute Asthma Exacerbation - Breathing exercise to stop up to 90% of asthma attacks in 2-3 min
Other references
Straub NC, Section V, The Respiratory System, in Physiology, eds. RM Berne & MN Levy, 4-th edition, Mosby, St. Louis, 1998.
Herxheimer H, Hyperventilation asthma, Lancet 1946, 6385: 83-87.
Herxheimer H, The late bronchial reaction in induced asthma, Int Arch Allergy Appl Immunol 1952; 3: 323-328.
