Precipitation of asthma attacks in Melanesian adults by sodium metabisulphite.

Seven Melanesian asthmatic patients were challenged with substances that have been shown to precipitate asthma attacks in asthma patients in developed countries. Patients were challenged in a double-blind fashion using placebo and active substances. The active substances were tartrazine, sodium metabisulphite, aspirin and betel nut. All 7 patients were challenged with tartrazine and sodium metabisulphite; 5 were challenged with aspirin also, but only 2 were challenged with betel nut. Asthma attacks were precipitated by sodium metabisulphite in 3 patients. No other substances precipitated asthma. As sodium metabisulphite is a common food additive, these results suggest that processed foods introduced into developing countries may have an important role in precipitating asthma attacks in susceptible persons.