Complementary and alternative medicine (CAM) has been used to treat asthma for hundreds of years. Moses Maimonides, a 13th-century physician prescribed an integrated life-style approach which included a diet of chicken broth with various herbs and spices. Today, the search for alternative therapies to complement conventional therapy continues. The article evaluates the merits of diet, dietary supplements, and herbal remedies.
Certain foods precipitate acute asthma attacks. Food allergies are thought to be mediated by immunoglobulin E antibodies and may cause asthma. Studies have shown the high prevalence of food allergies in asthmatic patients. Wheat, eggs, soy, nuts, and dairy products are thought to be some of the common foods to which a patient with asthma may be allergic.
Of the foods that trigger asthma, wines were the most common. There was also found a significant association between wine-induced asthma and asthma triggered by sulfite-containing foods. This finding implies that sulfite additives in wines may play an important role in the allergic reactions.
In one survey, low dietary intake of ascorbic acid has been associated with asthma. In one study, administration of 2 g of ascorbic acid significantly improved FEV1. In another, ascorbic acid given one hour before exercising show improvements in FEV1 in patients with exercise-induced asthma.
Omega-3 fatty acids
Fish oil supplements may help to relieve asthma symptoms. Fish oils contain eicosapentaenoic acid, an omega-3 fatty acid. However, some studies have failed to show improvements in FEV1.
A report showed zinc levels to be lower in patients with asthma. Another showed a positive association between low dietary zinc intakes and bronchial hyperreactivity. However, caution is needed. Occupational exposure to zinc has been reported to cause asthma.
Intravenous magnesium has been shown to have bronchodilating effects. A study found that airway hyperreactivity was significantly lower in persons who consumed diets rich in magnesium. The effect on asthma symptoms remain unclear.
Ma Huang is commonly used in China for the treatment of asthma. The active ingredient is ephedrine, which acts on b-receptors and causes bronchial relaxation. In excessive doses, ephedrine toxicity can cause serious adverse effects; sudden death has been reported.
Another common Chinese herb, ginkgo has been shown to have positive effects in asthma. After 4 weeks of treatment, patient's FEV1 improved by 10%; after 8 weeks, 15%, significantly greater than that achieved with placebo.
The tylophora indica plant is used to treat asthma in Indian (Ayurvedic) medicine. It is believed to control excessive mucus production. The results of studies have been mixed.
One of the most popular and best studied antiasthmatic herbal treatment, tsumura saiboki-to is widely used in both Japanese (Kampo) and Chinese medicine. It is a combination of two herbal preparations and contains 10 different herbs. Tsumura saiboki-to is claimed to have a steroid-sparing effect in corticosteroid-dependent asthmatic patients. In one study, the doses of corticosteroids could be decreased in 34% of patients.