Asthma can be one of the major symptoms of chronic food allergy, which contributes to the total overall antigenic load of a patient. Food-mediated allergic reactions may become clinically apparent immediately or even hours to days later in a patient with asthma, manifested by specific production by B lymphocytes of IgE and IgG antibodies to food proteins. From 20% to 60% of patients with bronchoconstrictive symptoms are reported to develop these symptoms as a result of food ingestion.13 One study demonstrated that the elimination of previously determined food allergens early in life resulted in decreased asthma symptomatology as well as inhibiting the progression of allergic tendencies (represented by decreased production of total and specific IgE) compared to a control group that did not undergo such eliminations.14 Increased gastrointestinal (GI) permeability and GI symptomatology has been found in a larger percentage of patients with asthma compared to controls without asthma symptoms; this may partially explain the origins of food-related allergy symptoms, such as asthmatic wheezing.15 Clinically, identification and removal of known and suspected food allergens does provide some amelioration of asthma symptoms in certain individuals. (See Chapter 17 on food allergies.)
The active form of pyridoxine (vitamin B6) found in the human body, pyridoxal-5-phosphate, has long been known to be depleted by theophylline, a drug now rarely used in asthma medication. Regardless of current or past theophylline use, patients who have asthma tend to have lower circulating levels of this vitamin and, in one study, supplementation with 50 mg of pyridoxine twice per day for patients with asthma resulted in subjective reports of dramatic decreases in frequency and severity of asthma attacks while taking the supplement.16 The study did not, however, indicate reasons for the apparent beneficial effects of pyridoxine supplementation. Another study placed 76 children with asthma on 200 mg of pyridoxine per day for five months. These patients reported significant reduction of asthma symptoms and reduced usage of asthma medications.17 However, in another study, nine weeks of treatment with 300 mg of pyridoxine produced no difference in peak expiratory flow rate (PEFR), FEV1, or asthma symptom scores compared to controls.18 Examples of studies such as these demonstrate the need for increased research in the realm of vitamin B6 supplementation for patients who have asthma.
Table 6-1. Doses of Supplements and Botanicals for Treating Asthma
Pyridoxine (vitamin B6) Ascorbic acid (vitamin C) Magnesium
Essential fatty acids (EPA DHA) Tylophora (Tylophora asthmatica)
Coleus (Coleus forskohlii)
25-50 mg, 2 times per day
2000-3000 mg per day, in divided doses
250-300 mg, 3 times per day
2000-3000 mg, in divided doses per day
Dried tylophora leaves: 200 mg, 2 times per day Or, alcoholic extract: 40 mg, 2 times per day Standardized extract containing 18% forskolin: 50 mg, 3 times per day
EPA eicosapentaenoic acid; DHA docosahexaenoic acid.
Reactive oxygen species are implicated in the disease process of asthma, as it has been previously demonstrated that specific allergens were able to initiate a neutrophil-derived respiratory burst in some allergen-sensitized patients with asthma.19 Excessive exposure to reactive oxygen and nitrogen species provides hallmark oxidative stress, propagating damage in proteins, lipids, and DNA structures. Oxidative stress in the lungs of patients with asthma is not only caused by intrinsic inflammatory pathways; environmental exposures, such as air pollution and cigarette smoke, also contribute. Interventions designed to augment endogenous antioxidant defenses are strongly indicated as adjuvant therapy for patients who are suffering from allergic respiratory disorders.20
Antioxidant supplementation, most notably vitamin C, can modulate the impact of air pollutants to reduce their effects on patients, including that of ozone on children with moderate to severe asthma.
Ascorbic acid (vitamin C) is one of the key antioxidant vitamins that are abundant in the extracellular fluid that lines the lungs, and low vitamin C intake has been associated with pulmonary dysfunction. One study reported that patients with asthma had significantly less ascorbic acid in both the cellular and fluid-phase fraction of induced sputum, suggesting that deficiency of ascorbic acid may be a result of airway inflammation or may be a contributing factor in the pathophysiology of asthma.21 Children with asthma who live in Mexico City were given a daily supplement combination of 50 international units of vitamin E and 250 mg of vitamin C for 19 months. Pulmonary function tests were performed twice per week, with significant differences in forced expiratory flow (25-75) and peak expiratory flow between the test and control groups. These results suggest that antioxidant supplementation, most notably vitamin C, can modulate the impact of air pollutants to reduce their effects on patients, including that of ozone on children with moderate to severe asthma.22 Consumption of antioxidants in foods as an asthma symptom preventative method has also been studied. Intake of citrus and=or kiwi fruit was a highly significant protective measure for reducing wheezing among children who ate fruit five to seven times per week compared to children who ate fruit less than once per week. This protective effect was even evident among the group whose fruit intake was only one to two times per week compared to those who consumed fruit less than one time per week, although no clear dose-response relationship was elucidated.23 It appears that even relatively low dietary doses of vitamin C are protective against asthma symptomatology in children. Prophylactic administration of ascorbic acid for prevention of exercise-induced asthma is widely described in the medical literature, with most studies revealing that taking vitamin C produces moderately beneficial effects to reducing asthma symptoms caused by exercise but results in little change in pulmonary function tests. The main conclusions drawn from these studies are that vitamin C demonstrates a slight to moderate protective effect on airway hyperreactivity in patients with exercise-induced asthma.24 A wide review of studies that have investigated the use of vitamin C for treating asthma and allergy found that, among the significantly positive effects of this therapy, positive effects on pulmonary function tests, methacholine, histamine, or allergen broncho-provocation challenges, lymphocyte function and motility, and decreased respiratory infection incidence were produced. No benefits were noted in these studies regarding testing of cutaneous reactivity or more specific immunologic parameter measurements. This main study also showed that the majority of vitamin C-asthma investigations were short-term and only addressed the immediate effects of vitamin C supplementation on asthma symptoms.25
Was this article helpful?