What Causes Asthma
If you ask your doctor what causes asthma, the answer is "I don’t know".
What is known is that asthma is more prevalent in affluent countries. (1-4)
It is generally thought that this is due to the hygiene hypothesis of lower exposure to infection during childhood, which results from improved living standards. However, "Challenging this hypothesis, there is growing evidence that in many affluent countries the prevalence is higher among those in low socio-economic status. (5-14) These socio-economic differentials in asthma support a role of environmental factors in the development of asthma." 15
So what are the environmental factors and how do they cause asthma?
As we become wealthier, our lifestyles change and this has a significant affect on the way that we breathe. With modern living we eat more processed foods, overeat, do less physical exercise, experience more stress and have higher temperatures in the home. Jobs in the modern economy tend to be service-based. As a result they entail very little physical activity and many hours of talking. In addition we are subjected to the unhealthy belief that prevails in gyms, sports class, stress counselling and even western Yoga about the benefits of big breathing.
The modern western lifestyle has quite a profound influence on our breathing- IT INCREASES IT.
Throughout this book in explaining the Buteyko method, I will use different terms such as heavy breathing, overbreathing, chronic hyperventilating, big breathing. They all mean the same thing and are the crux to explaining the cause of asthma and rhinitis.
Buteyko Breathing is based on the premise that asthmatics chronically hyperventilate
If I told you that you were overeating, you would understand what I mean. Overeating is eating an amount of food greater than that which our body requires.
Likewise, overbreathing means breathing a volume of air greater than that which we require. You might say that you don’t over breathe; but for most people it is hidden.
Listed below is a number of characteristics which are typical of people attending my clinics? How many apply to you?
- Breathing through the mouth
- Hearing breathing during rest
- Regular sighs
- Regular sniffing
- Irregular breathing
- Holding of breath (apnoea)
- Taking large breaths prior to talking
- Yawning with big breaths
- Upper chest movement
- Lot of visible movement
- Effortful breathing
- Heavy breathing at night
Normal Breathing Volume:
The number of breaths per minute during normal breathing is about 10 to 12. Each breath is approximately 500 ml. This provides a healthy volume as described in any University Medical textbook of 5 to 6 litres of air per minute.
Typical Asthmatic Breathing Volume:
The number of breaths per minute of a typical asthmatic is about 15-20. Each breath tends to be larger than normal and can vary from 700ml to 1 litre. This provides a volume of 10 to 15 litres of air per minute. A number of trials found that the average minute volume for asthmatics was 14.1 litres (Bowler 1998), other researchers showed a volume of 15 litres (Johnson et al 1995) and 12 litres (McFadden & Lyons 1968). (16-18)
"Noisy and deep" breathing of an asthmatic had always been considered an outcome of the disease. Nobody could even suspect that "deep breathing" was the cause of bronchial asthma, and increased depth of breathing could provoke the appearance of the symptoms of the disease. K P Buteyko MD
Accoring to the Buteyko Method, this heavy breathing does not just happen during a symptomatic period. It is chronic meaning that it takes place every minute, every hour, every day.
People with asthma, COPD and other respiratory complaints breathe two to three times more than required. In food terms, this is the equivalent of eating ten meals per day. We can live without food for a number of weeks and without water for a number of days. We can only live without air for just a few minutes. Surely air, which is so vital to sustaining life, must meet certain parameters?
Why do we overbreathe?
There are many reasons why we overbreathe and not all of them apply to each individual. The following seven factors are more prevalent in countries of increasing modernisation and affluence, and this helps explain why asthma and rhinitis are so prevalent.
- Diet- Overeating increases breathing volume due to the additional work that is required by the body to process and digest the extra food. Secondly, processed foods are generally acidic. The body strives to maintain the correct pH of the blood and increases breathing in order to remove carbon dioxide.
- During speaking, large breaths of air are inhaled between each sentence. People who work in sales, call answering and teaching will be very aware of how tired and chesty they can be following a number of days talking.
- Stress activates the fight or flight response. We react the same way to a modern day stress as we did to meeting a predatory animal thousands of years ago. When confronted by a wild animal, we had the option of fighting it or running away as fast as possible. In this situation, our breathing increases to prepare us for physical activity.
- When we move our muscles, we generate greater amounts of CO2. Nowadays, lack of exercise results in lower production of CO2, and therefore larger breathing volume. Fifty years ago, it is estimated that we performed four hours of physical exercise each day. Today, many people are lucky if they have half an hour of exercise daily.
- The belief that it is good to take big breaths. Stress counselors, gym instructors, coaches, and media personnel who are misinformed about correct breathing volume often encourage the practice of taking a big breath to allow more oxygen into the body. The confusion may lie in the belief that a deep breath is a big breath. A deep breath is what a baby takes and this can be observed by the movements of the tummy. A big breath is often taken through the mouth and generally involves upper chest movement. They are entirely different.
- Asthma symptoms. As airways constrict, we feel suffocated. As a result our breathing increases to try and remove this feeling. However, this increase of breathing volume further feeds our symptoms causing greater constriction and thus a vicious circle is maintained. Later on, I will show you a very gentle exercise to stop this cycle.
- Higher temperatures within the home increase breathing. Another factor is because we are so well clothed; we are less able to regulate body temperature through the skin. This encourages us to revert to the primitive way of heavier breathing to regulate body temperature.
Overbreathing and genetic predisposition
It can be argued that the same percentage of the population carries the asthma gene today as did years ago. After all, we evolve over thousands of years. While asthma has been around for a long time with first reports dating back to the Ancient Egyptians, it only affected a small percentage of the population until the second half of the twentieth century. For example, the incidence of self reported asthma increased in the US by 74% between 1980 and 1996. 19
Modern living has resulted in a profound change to our breathing. The affect that overbreathing has on the individual depends on genetic predisposition.
If you carry the "asthma gene" and you overbreathe, you will develop asthma. On the other hand, if you carry the "asthma gene" but don’t have the habit of overbreathing, you will not develop asthma.
Lastly, when you correct your overbreathing, asthma reverses.
Just a Habit
The good news is that overbreathing is just a habit. The part of your brain (central chemoreceptor) that regulates the amount of air you breathe becomes accustomed to breathing too much. Through application of the Buteyko breathing exercises, this habit is reversed.
In a paper entitled Hyperventilation Syndrome and Asthma, Dr Stephen Demeter states "prolonged hyperventilation (for more than 24 hours) seems to sensitize the brain, leading to a more prolonged hyperventilation." 20 Hyperventilation becomes habitual or long term, so even when the primary cause is removed, the behavior is maintained.
With the various exercises outlined in this book, I will teach you how to bring your breathing volume down to more normal amounts, thereby reversing your asthma.
In other words, I will teach you to breathe less.
How does overbreathing cause asthma?
Your airways narrow due to a combination of different factors. The most prevalent is inflammation, which is swelling of the inner wall of your airways. Another is constriction by the smooth muscle that surrounds your airways and a third is increased secretion of mucus by goblet cells.
An asthma attack is used to describe a period of breathing difficulty. An attack can range from a few coughs or a mild wheeze to a life-threatening experience.
There are different theories as to why overbreathing causes airways to narrow. One is that airways cool and/or dehydrate from having to condition such a large volume of air.
A paper by Davis and Freed published in the European Respiratory Journal concluded, "repeated dry air challenge in dogs in vivo causes persistent airway obstruction and inflammation not unlike that found in human asthma." (33)
Professor Buteyko and others point to the loss of Carbon Dioxide (CO2). (35-39)
In a paper entitled The Mechanism Of Bronchoconstriction Due To Hypocapnia In Man, Sterling writes, “hypocapnia (loss of Carbon Dioxide) due to voluntary hyperventilation in man causes increased resistance to airflow”. Furthermore, when subjects inhaled an air mixture containing 5% carbon dioxide "bronchoconstriction was prevented, indicating that it had been due to hypocapnia, not to mechanical factors associated with hyperventilation" 41
Why is Carbon Dioxide so important?
Carbon Dioxide (CO2) is generated as an end product from the oxidising of the fats and carbohydrates you eat. The CO2 is carried by your veins to your lungs, where the excess is exhaled. Breathing a correct volume results in the required amount of CO2 being retained in your lungs. When you overbreathe, too much CO2 is exhaled. The human body requires a certain amount of it for normal functioning.
"Carbon Dioxide is, in fact, a more fundamental component of living matter than is Oxygen.” Yandell Henderson cited in Normal Breathing- The Key to Vital health by Dr. Artour Rakhimov. 40
Carbon Dioxide is not just a waste gas. It is necessary for a number of vital bodily functions including the following:
Buteyko Breathing improves transportation of Oxygen
Oxygen is relatively insoluble in blood, so approximately 98% of the gas is carried by haemoglobin molecules. The release of Oxygen from haemoglobin is dependent on the quantity of Carbon Dioxide in your alveoli/arterial blood. If the Carbon Dioxide is not at the required level of 5%, the Oxygen "sticks" to haemoglobin and so is not released to tissues and organs.
This bond was discovered in 1904 by Bohr and is known as the Bohr Effect.
During normal conditions 75% of your intake of Oxygen is exhaled while breathing a healthy volume of 4 - 6 litres per minute. Even during intense exercise, it is estimated that 25% of our intake of Oxygen is exhaled. Breathing a volume greater than normal does not improve the amount of Oxygen in your blood, as it is already 97 - 98% saturated. Instead it lowers CO2 levels, firstly in your lungs, then in your blood, tissues and cells and this reduces the delivery of Oxygen from the haemoglobin within your red blood cells.
The greater the amount of air taken into your body, the less Oxygen is delivered.
To oxygenate tissues and organs, modern man needs to breathe less not more.
Buteyko Method dilates blood vessels and airways
Carbon Dioxide relaxes smooth muscle which surrounds airways, arteries and capillaries.
For example, each 1mmHg drop (norm is 40mmHg) of arterial CO2 reduces blood flow to the brain by 2%.42 In other words, oxygenation of your brain significantly decreases when you breathe heavily. It is no coincidence that symptoms such as fatigue, brain fog, anxiety and poor concentration etc. are common among asthmatics as chronic overbreathing is contributing to them all.
For those genetically predisposed to asthma, the loss of CO2 from the lungs causes the airways to constrict.
The heavier you breathe- the more you feed your asthma and other hyperventilation-related problems. The calmer and quieter you breathe, through application of the Buteyko Method- the more your blood vessels and airways open.
Overbreathing increases allergic reactions.
Histamine levels increase during prolonged overbreathing. (43-44) Histamine is a substance secreted by mast cells during exposure to an allergen. This substance creates swelling (edema), local inflammation and constriction of the smaller airways (bronchiole). This is especially relevant to people with hay fever (rhinitis) and asthma.
These are typical symptoms of persons presenting themselves for instruction in Buteyko. How many of the following symptoms of hyperventilation do you have?
- Respiratory system: wheezing, breathlessness, coughing, chest tightness, frequent yawning, snoring and sleep apnoea.
- Nervous system: light-headed feeling, poor concentration, numbness, sweating, dizziness, vertigo, tingling of hands and feet, faintness, trembling and headache.
- Heart: a racing heartbeat, pain in the chest region, and a skipping or irregular heartbeat.
- Mind: some degrees of anxiety, tension, depression, apprehension and stress.
Other general symptoms include mouth dryness, fatigue, bad dreams, nightmares, dry itchy skin, sweaty palms, cramping, spasm, increased urination such as bed wetting or regular visits to the bathroom during the night, diarrhea, constipation, general weakness and chronic exhaustion.
Cardiologist Claude Lum comments that: "Hyperventilation presents a collection of bizarre and often apparently unrelated symptoms, which may affect any part of the body, and any organ or any system." 45
In the late Professor Buteyko’s words "Exhaling Carbon Dioxide from the organism brings about spasms in bronchi, vessels and intestines etc. This reduces Oxygen supply leading to Oxygen deficiency making one breath heavier, thus completing the vicious circle."
Practical examples of overbreathing affecting asthma
Exercise causes airway narrowing for an estimated 70-90% of asthmatics.46 In fact, I have yet to see a moderate to severe asthmatic who is not affected by physical exercise. Breathing increases as soon as you commence physical exercise. The heavier your breathing is relative to your metabolic requirements, the greater the degree of airway narrowing.
The second example of overbreathing causing asthma within a few minutes is laughter. We all know a friend or relative who gets into a fit of coughing or wheezing from having a good hearty laugh. As one starts to laugh, large breaths are drawn through the mouth. For some people, 30 seconds of laughter is enough to produce symptoms.
A report published by the America Thoracic Society in May 2005 concluded that laughter causes symptoms among 57% of asthmatics.47 In the same report asthma expert Dr. Garay commented, "Nobody knows how laughter brings on asthma, but it might involve hyperventilation."
So the question to ask is; if you can take yourself into symptoms from a few minutes of laughter or exercise, does it make sense that if your breathing is 2 - 3 times more than required at all times, then it too will cause symptoms?
Why is swimming beneficial?
For years, medical doctors have been telling their asthma patients that swimming was good for them even though, they may not have exactly known why. The answer is simple; during swimming, your face is under water and this reduces your air intake. Although, you may take a breath in through your mouth every few strokes, your breathing volume is a lot less that if you were running or doing other exercise.
As you exercise, CO2 is produced from metabolic activity. This, combined with the reduced breathing volume from swimming, increases CO2 levels and this in turn dilates your airways. It is unfortunate that asthmatic swimmers are not aware of this and often revert to heavy breathing through the mouth as soon as they leave the water.
"One needs to eat less, breathe less, sleep less and physically work harder to the sweat of one’s brow because this is good. This is a fundamental change, this is true restructuring. This is what we need to do these days."
Professor Konstantin Buteyko