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Exercise-Induced Asthma and the Use of Peppermint

Exercise-induced bronchospasm, exercise-induced bronchoconstriction and exercise-induced asthma (EIA) are all terms used to describe the condition defined as a temporary (transient) narrowing of the airways induced by strenuous physical exertion; EIA can be considered as bouts of asthma with bronchospasm being the main component triggered by exercise. EIA can differ from other kinds of asthma attacks since it frequently involves airway constriction only with little or none of the swelling and secretions of mucus. And so, EIA is a reversible condition in which the smooth muscle in the airways constricts in response to physical acitivty.

(The term "exercise-induced asthma" is a misnomer , as exercise, unlike allergen inhalation, is not known to cause asthma. Thus, the term "exercise –induced bronchoconstriction" [EIB] may be preferred and may help remove the confusion, often held by parents of asthmatic children, that exercise should be avoided because it worsens the child's asthma. "Exercise-induced Bronchoconstriction: Elucidating the Roles of Leukotrienes and Prostaglandins," PM O'Byrne, Pharmacotherapy 17 (1 PT 2): 31S-38S, 1997.)

EIA is a common problem that affects millions of people. Up to 90% of asthmatics and 40% of patients with allergic rhinitis (inflammation of the nasal mucous membrane) have EIA. Between 6 and 13% of the normally non-asthmatic population have EIA. Athletes with either asthma or EIA can compete to the highest level as demonstrated by the 41 out of 67 athletes with asthma on the U.S. team who won medals at the 1984 Olympics. Also of note is that 32 of these athletes were unaware they had EIA until after selection for the team.



EIA classically occurs near the initiation of exercise (actually may not require intensity of exercise, personal communication of coauthor, Falkner) and bronchoconstriction occurs 5-15 minutes after exercise is finished and is usually is over within 30 minutes of the start of the attack. The symptoms may include: wheezing, chest tightness, coughing, chest pain and prolonged shortness of breath.



If medication is needed – short-acting beta2-agonists have long been the mainstay and first line of treatment for EIA. Peppermint with its active ingredient menthol has smooth muscle relaxant properties and has been effectively used in the treatment of Irritable Bowel Syndrome, (IBS).

It has been reported that menthol has a similar relaxing effect on the airway smooth muscle in patients with mild asthma Tamaoki J, Chiyotani A, Sakai A, Takemura H, Konno (Effect of menthol vapor on airway hyper-responsiveness in patients with mild asthma. Resp. Med. 89: 503-4, 1995). When peppermint is taken in the form of mint - staying in the mouth for a longer period of time – the menthol then vaporizes slowly and is then inhaled into the respiratory system, arriving at various sites along the respiratory tract in sufficient amount to provide relief from the bronchospasms caused by strenuous exercise.

Calcium channel blocking agents such as Nifedipine (Procardia) have been used in the treatment of asthma and EIA. Calcium is the key to all nerve conduction signals and muscular contraction; without it a person would not have the ability to complete the next heartbeat or be able to breath. Inhaled menthol acts as a specific inhibitor of calcium dependent processes by inhibiting the movement of calcium across cell membranes affecting sensory nerve endings and smooth muscle contraction—thus may locally relax the smooth muscle in the lungs, and facilitate breathing.

See related module - Peppermint Use to Assist in Asthma Control.

EIA preventive measures would involve avoidance of triggers, combined with modifying the exercise program and possibly taking some form of peppermint that can be vaporized slowly before and even after an exercise program.

Here's a list of some preventive measures:

• Train in a warm, humid environment. This will help to maintain warmth and moisture in the respiratory airways.
• Wear a mask or scarf over the nose and mouth when exercising in a cool or dry environment to retain heat and moisture.
• Breathe slowly and deeply through the nose as much as possible. The nasal passages help to warm and humidify inhaled air before it reaches the lower respiratory tract.
• Train during a time of day when the amount of pollen and the amount of air pollution is low. This will help to avoid some of the primary triggers of asthma and EIA.
• Develop some breathing exercises and relaxation techniques to help through the next EIA attack. The ability to control hyperventilation will help prevent the exacerbations of EIA.
• Avoid any food that may trigger EIA, at least four hours before any type of exercise. Research suggests that by increasing water consumption and possibly vitamins B, C and E intake may also assist in avoiding an attack. Iron supplements have also been proposed as a means of treatment.
• Follow daily and pre-exercise medication (and menthol/peppermint use) schedules as recommended by your physician.
  
  Good luck and remember exercise does not cause asthma. The aim of management of EIA must be to ensure that exercise not be avoided. Patients with asthma including children should exercise as much as they wish and should be encouraged by the fact that many Olympic-caliber athletes have symptomatic asthma.