The Etiologies, Pathophysiology, and Alternative/Complementary Treatment of Asthma

Alternative Medicine Review, Feb, 2001 by Alan L. Miller

Abstract

A chronic inflammatory disorder of the respiratory airways, asthma is characterized by bronchial airway inflammation resulting in increased mucus production and airway hyper-responsiveness. The resultant symptomatology includes episodes of wheezing, coughing, and shortness of breath. Asthma is a multifactorial disease process with genetic, allergic, environmental, infectious, emotional, and nutritional components. The underlying pathophysiology of asthma is airway inflammation. The underlying process driving and maintaining the asthmatic inflammatory process appears to be an abnormal or inadequately regulated [CD4.sup. ] T-cell immune response. The T-helper 2 (Th2) subset produces cytokines including interleukin-4 (IL-4), IL-5, IL-6, IL-9, IL-10, and IL-13, which stimulate the growth, differentiation, and recruitment of mast cells, basophils, eosinophils, and B-cells, all of which are involved in humoral immunity, inflammation, and the allergic response. In asthma, this arm of the immune response is overactive, while Th1 activity, generally corresponding more to cell-mediated immunity, is dampened. It is not yet known why asthmatics have this out-of-balance immune activity, but genetics, viruses, fungi, heavy metals, nutrition, and pollution all can be contributors. A plant lipid preparation containing sterols and sterolins has been shown to dampen Th2 activity. Antioxidant nutrients, especially vitamins C and E, selenium, and zinc appear to be necessary in asthma treatment. Vitamins B6 and B12 also may be helpful. Omega-3 fatty acids from fish, the flavonoid quercetin, and botanicals Tylophora asthmatica, Boswellia serrata, and Petasites hybridus address the inflammatory component. Physical modalities, including yoga, massage, biofeedback, acupuncture, and chiropractic can also be of help.

Altern Med Rev 2001;6(1):20-47.

Introduction

Asthma is a chronic inflammatory disorder of the respiratory airways, characterized by increased mucus production and airway hyper-responsiveness resulting in decreased air flow, and marked by recurrent episodes of wheezing, coughing, and shortness of breath. It is a multifactorial disease process associated with genetic, allergic, environmental, infectious, emotional, and nutritional components. Because of their symptomatology the majority of individuals with asthma experience a significant number of missed work or school days. This can create a severe disruption in quality of life, often leading to depressive episodes. It also disrupts the lives of caregivers and family members of the affected individual. Asthma patients who have increased symptomatology at night (a significant portion) also tend to have disturbed sleep patterns and impaired daytime attention, concentration, and memory.[1]

In 1998 it was estimated that asthma affected 17.3 million individuals in the United States and 150 million worldwide. From 1980-1995 the incidence of asthma in children under age 18 increased five percent per year, resulting in an increase of more than 100 percent in that time period, according to the National Health Interview Survey (NHIS), the mechanism the U.S. government uses to gather data regarding asthma prevalence and mortality. The current overall prevalence in children is estimated at 6.0-7.5 percent, with a total of over five million children affected. Asthma is the fourth-leading cause of disability in children, and one of the most common reasons for school absenteeism. The prevalence in adults is approximately five percent. Asthma prevalence among African-Americans is considerably higher than Caucasians or Hispanics, with black children having a 26-percent greater incidence than white children in 19951996.

Approximately 5,000 people die each year due to asthma. Across racial and socio-economic groups, the death rate from asthma mirrors the incidence, with African-Americans having the highest mortality from this disease. The death rates for asthma are higher in the inner city and in lower socioeconomic groups. The exact cause of these differences might be due to genetic, socioeconomic, and/or access to health care issues. Direct costs (doctors' visits, hospitalization, drugs, etc.) and indirect costs (work and school absenteeism, etc.) of asthma vary, depending on the reference, but are estimated to be approximately $6 billion per year.

Why the ever-increasing incidence of asthma in the last three decades? Some blame new home construction in the 1970s, when higher fuel costs prompted the construction of more airtight homes. Newer houses are more insulated and have less air exchange than older homes. Wall-to-wall carpet is much more common, as is central heating. Synthetic building materials laden with chemicals also enjoy greater utilization by builders. These "improvements" in construction make for a more closed micro-environment that has insufficient fresh air and is more conducive to the growth of microorganisms.

Other researchers point the finger at environmental pollutants. Industrialization of countries and the use of fossil fuels have paralleled the incidence of respiratory disease. There is good evidence that the increases in ozone, nitrogen dioxide, sulfur dioxide, and particulates in the atmosphere have exacerbated allergic diseases, including asthma, due to irritant effects of these substances causing chronic inflammation, as well as interactions with allergens and amplification of allergic reactions.[2,3]