Asthma symptoms are aggravated by exposure to allergens, such as pollen, dust and air pollution. At high altitudes, the concentrations of the allergens are reduced due to the reduced amounts of vegetation, animal populations and human influences. High altitudes of approximately 1,500 m might have effects on the frequency and severity of asthmatic symptoms, but medical evidence is conflicting on the therapeutic benefits.
High Altitude Therapy
High altitude therapy has been recommended for the treatment of pulmonary diseases for more than a century, according to the June 2011 issue of "Clinical and Experimental Allergy." The authors stated that dry mountain air contains reduced levels of pollens, fungal spores and pollution, and will lessen the severity of asthma and allergic reactions. In this review article, the authors found preliminary evidence to suggest that high-altitude therapy is a beneficial option for patients suffering from debilitating lung diseases.
Asthmatic Symptoms
A clinical study published in the August 2010 issue of the "Journal of Asthma" investigated the effects of high altitudes of the incidence and severity of asthma in 24 Dutch patients during a trekking expedition in the Tibetan region of Mount Everest. Asthma symptoms and other parameters were measured at altitudes of 1,300 to 6,410 m and compared to healthy controls composed of the seven members of the expedition staff. The study found that asthma symptoms did not improve or worsen with increasing altitude, but the heart rate of the asthmatics increased significantly at altitudes of 6,410 m.
Conflicting Evidence
Lower altitudes have significant beneficial effects for bronchial asthma patients but lessen with increasing altitudes, according to a review article in the June 2009 issue of "High Altitude in Medicine and Biology." The authors found conflicting evidence of health benefits of moderate altitudes to asthmatics and no clinical data to support altitude therapy; however, they noted that at high altitudes the environment is not harmful to those with well-controlled asthma.
High UV Levels and Low Humidity
The German medical periodical "Pneumologie" examined the benefits of altitudes higher than 1,500 m in more than 400 asthmatic patients. At these altitudes, the authors found that the patients' dependence on steroid therapy was significantly reduced and they experienced a profound reduction in inflammatory cell production. The study concluded that high UV light exposure and low humidity could be contributing factors to the benefits of high altitude other than allergen avoidance.
References
- "High Altitude in Medicine and Biology"; Bronchial Asthma: Advice for Patients Traveling to High Altitude; A. Cogo, et al; June 2009
- "Journal of Asthma"; Asthma in Patients Climbing to High and Extreme Altitudes in the Tibetan Everest Region; H. Huismans, et al; August 2010
- "Clinical and Experimental Allergy"; High-Altitude Treatment: A Therapeutic Option for Patients with Severe, Refractory Asthma?; L. Riissenbeek-Nouwens, et al.; June 2011
- "Pneumologie"; Effects of High Altitude on Bronchial Asthma; G. Schultze-Werninghaus; March 2008
