ABSTRACT: The nervous and biochemical factors involved in the pathogenesis of asthma are discussed from the view point of the possible influence of Yoga. Some epidemiologic evidence and personal teaching experience related to the effectiveness of Yoga in the management of asthma is then presented.
Yoga has many therapeutic applications but is most effective in diseases with a recognised psychosomatic component such as asthma. To understand how Yoga can affect asthma it is necessary to know a little about the pathogenesis of this disease.
Present-day knowledge about the pathogenesis of asthma has clearly pointed out that the problem lies in hyper-responsiveness of the bronchus.*1 The cause of this hyper-responsiveness is an imbalance in the autonomic nervous system. We know that stimulation of the parasympathetic nervous system brings about bronchial constriction and that stimulation of the sympathetic causes bronchodilation.
The normal calibre of the bronchus is maintained by a balanced functioning of these systems, which both operate reflexively. The parasympathetic reflex loop consists of afferent nerve endings which terminate under the inner lining of the bronchus. Whenever these afferent nerve endings are stimulated (for example, by dust, cold air or fumes) impulses travel to the brain-stem vagal centre, then down the vagal afferent pathway to again reach the bronchus. Acetylcholine is released from the afferent nerve endings. This acetylcholine results in the excessive formation of cyclic Guanine Mono phosphate (GMP). This initiates bronchoconstriction.
The sympathetic reflex loop consists of impulses travelling from the hypothalamus to end in the adrenal medulla and there to release epinephrine. Epinephrine is carried in the bloodstream to the bronchus where it activates sympathetic receptors which in turn stimulate the bronchial cells to promote the formation of cyclic Adenosine Monophosphate (cAMP). This substance relaxes the bronchial smooth muscles. Of course, as the muscles around the bronchi relax, their calibre increases and air flows more easily.*2
However, this delicate balance between cyclic AMP and cyclic GMP, which maintains the calibre of the bronchus, is also influenced by the activities of "mast cells".*3 When allergens such as pollen, animal hairs or skin, house dust, chemicals or drugs are taken up into the blood, the immune system of the body, considering them to be highly dangerous substances, wants to fight them away. In people with an abnormally sensitive immune system, large amounts of immunoglobulins (IgE and Icg) are brought to the site of the insult in the nose and the bronchi. Here allergens and antibodies may react on the surface of sensitised "mast cells" lying on or underneath the mucus membrane.
This disruption of the mast cells leads to the release of chemical mediators stored within them. Some of these chemical mediators are: cistamine, chemotac-tic substances, leukotriones and prostaglandins. These chemicals upset cGMP - camp balance by acting directly on their lung receptors and or through the vagal receptors.
With this background we can suppose that Yoga might affect asthma through the following mechanisms:
Yoga nidra by balancing activity in both hemispheres of the brain (as I established with Brain Electrical Activity Mapping experiments at Charing Cross Medical School in 1988) could lead to rectification of any disturbances in the autonomic nervous system.
Asana Regular practice of asanas has been shown to induce certain biochemical changes, such as increased catecholamines and corticosteroids*4 and it may be that here is one way that the biochemical imbalance could be altered.
Pranayama is renowned for increasing the vitality, what we in Yoga call the prana. The vitality in asthmatics is low. If you see a Kirlian photograph of the hands and feet of a healthy person and beside them the hands and feet of an asthmatic, some interesting things can be noticed. There is no radiation at all from the feet of the asthmatic. Perhaps this confirms a general psychological assessment that some asthmatics may not have their feet firmly on the ground.
Also fascinating is dissection of the aura that occurs in the thumb of the asthmatic, the traditional site of the lung meridian according to acupuncture.
Nadi shodhana pranayama (alternate nostril breathing) also, I believe, has a powerful effect on the autonomic nervous system. I did some preliminary work at Charing Cross Medical School (and I believe a report has already been published), showing the association between nasal flow and contra-lateral brain hemispheric activity.
Jala neti the passing of lukewarm saline water in one nostril and out the other by means of a lota, in my experience, is able to significantly reduce the effects of allergic rhinitis.
Kunjal with the powerful surge of vagal activity involved in the vomiting reaction, probably also assists to rectify autonomic imbalance. Further, the strong downward contraction of the diaphragm and simultaneous contraction of all the abdominal muscles impulsively stimulated in kunjal are the very physiological reactions required to assist with expiration.*5
On arrival, I announced throughout the Cambridge area and through local yoga teachers the availability of yoga classes for people suffering from complaints such as backache, asthma, insomnia and anorexia nervosa. All these problems have a high psychosomatic component which makes them particularly suitable for yoga therapy. I ended up teaching a class of about 19 asthmatics on Saturdays, This lasted for two years. Instruction started with the pawanmuktasana part I series. This was more effective in loosening their joints and they said it made them feel "more relaxed and energetic". The more dynamic pawanmuktasana part II and surya namaskara were only given to the younger subjects, after a couple of weeks of the course.
The older subjects did not like surya namaskara. They said it made them feel tired, less energetic and caused heavy breathing. All patients felt less tense and more energetic after pranayama: nadi shodhana, bhastrika.
Kunjal and especially jala neti was found particularly useful in drainage of mucus. It was a regular event for patients to go outside to clear their nose. We even designed a plastic neti pot to meet the continuing demand.
Yoga nidra was found particularly beneficial in inducing sleep and relaxing sleep. I also utilised a practice where during an attack patients sat on the floor and rested their heads in the crook of their arm on the seat. This helped to relax their breathing muscles, and to restore calm.
Some case reports
Let me now present some case reports illustrative of the way in which Yoga therapy works with asthma.
Mr. G. G. was aged 75 and had been suffering from severe bronchial asthma for 25 years. He used to wheeze and cough every night after 2a.m. and as a result he was unable to sleep well. He used to come to every class tired and exhausted. I suggested that he do chair-breathing at the time of acute attack. After resting his head on the chair in a curved posture, normal breathing would return in 10-15 minutes. Then he would lie down and play a yoga nidra tape.
To my surprise, the first day he reported that he had started snoring and bad fallen asleep in 15 minutes. With one month's practice, slowly the duration and severity of attacks was reduced. He now has restful sleep and feels more energetic.
Mrs. A. T. was aged 40. For 15 years she had suffered from bronchial asthma which was intense in the period of March to May. This is spring in England and pollens are thick in the air. She experienced a stuffed nose, heavy breathing and dry wheezing. She used to feel very heavy all along her eyebrows, forehead and sinus area.
I suggested that she do kunjal and neti every morning and take a hot bath. Regular practice made her more relaxed around the eyebrows, heaviness in the head was gone and she was no longer suffering from a stuffed nose. During the period of this practice she experienced no attacks.
Miss R. D. was aged 20. She had suffered from bronchial asthma for 15 years with a constant wheeze and a nose clogged with mucus. Heavy breathing and acute attacks used to come only in winter. I asked her to practise pawanmuktasana parts I and II, and surya namaskara. She said she found these practices very refreshing, and that she was feeling "energetic and relaxed" after regular practice.
After pranayama she used to go out of the class and drain a large amount of mucus from her nose. I had also asked her to stop eating yoghurt (dahi) and banana. These foods are traditionally associated with excess mucus product ion according to Yoga philosophy. After a few months the problem with her blocked nose had ceased.
Mr. D. R. aged 35, had bronchial asthma, with wheezing cough, restless sleep and emotional disturbance for 15 years. I asked him to practice yoga nidra when going to bed. The very next day he came and embraced me saying, "Yoga nidra is very powerful. I have never experienced such a calm, restful sleep in the present decade. When I started your tape I didn't know that within 10 minutes it would lead me to a deep sleep. When I woke up this morning it was 8a. m. I felt very energetic and there was no asthma attack last night".
Afterwards he practised yoga nidra every night before going to bed. In a few months he reported feeling much more energetic. He had few attacks and those that came were of reduced severity.
So, this is a brief picture of the pathogenesis of asthma and some thoughts on its yogic management.