http://www.lef.org/protocols/respiratory/asthma_01.htmUnderstanding Asthma: Inflammation and Oxidative Stress
Asthma is primarily a disorder of the bronchial tubes, the airways that connect the windpipe (trachea) and the lungs. The bronchial tubes are surrounded by smooth muscle. The tubes themselves are lined with mucus glands and contain inflammatory immune-system cells called mast cells, lymphocytes, and eosinophils. When activated, these cells produce inflammatory mediators such as histamine and leukotrienes, which bind with receptors on cells within the bronchial tubes.
During as asthma attack, a cascade of events is launched that results in the production of histamine and leukotrienes. Leukotrienes are derived from the inflammatory arachidonic acid. These inflammatory mediators cause a host of changes in bronchial tissue: they trigger a dramatic increase in mucus secretion and a simultaneous rapid constriction of the bronchial smooth muscle, which narrows the bronchial tubes and reduces the amount of air that can pass through them. Over the course of the subsequent few hours, inflammatory cells move into the area, capillaries begin to leak fluid, and direct tissue damage occurs, triggering further inflammation and swelling. The net result is wheezing and coughing and eventual trapping of air in the alveoli (a tiny, thin-walled, capillary-rich sac in the lungs, or air sac) and smaller airways. This air trapping is most dangerous to the asthmatic because it progressively limits the amount of air that can be exchanged between the lungs and the blood stream, eventually causing rising carbon dioxide levels and falling oxygen levels. The increased muscular effort required to move air increases oxygen demand, tissue metabolism, and acid production, eventually resulting in exhaustion and, in extreme cases, respiratory collapse and arrest.
Why the bronchial tubes become so sensitive in asthmatics is not fully understood, but research suggests that immune-system cells known as T cells play a central role. Some T cells induce inflammation to fight off a foreign threat, while others reduce inflammation once the threat has subsided. Conditions such as asthma, in which the body overreacts to threats, may be related to an imbalance or malfunction of these and other immune-system components (Tosca MA et al 2003; Howard TD et al 2002; Ray A et al 2000).
The idea behind nutritional supplementation is to disrupt this inflammatory cascade whenever possible. For example, omega-3 fatty acids have been shown to inhibit the production of arachidonic acid, which reduces the concentration of inflammatory leukotrienes (Wong KW 2005). Other nutrients, such as curcumin, interfere with other causative factors in the inflammatory cascade, such as inhibiting nuclear factor kappa beta and an enzyme that converts arachidonic acid to leukotriene B4.