Betelnut chewing causes bronchoconstriction in some asthma patients.

A previous questionnaire interview had revealed that betelnut chewing may aggravate asthma in 61% of asthma patients attending an outpatient clinic at Port Moresby General Hospital; the rest said it had no effect. The aim of the present study was to verify patients' subjective feelings through objective measurements. 7 asthma patients (Group C) who said betelnut aggravated their asthma, 8 asthma patients (Group B) who denied any effect and 8 nonasthmatic, healthy subjects (Group A) were given betelnut with accompanying ingredients and asked to chew as they would usually chew it. Their spirometric forced expiratory volume in the first second (FEV1) readings, heart rate and blood pressure were monitored before and after this challenge. Group A nonasthmatic subjects experienced only minor rises and falls in their FEV1 in response to betelnut chewing. 3 patients in Group B experienced overall rises (mean maximal % rise 25 +/- 19) while 5 patients had overall falls (mean maximal % fall 11 +/- 6). In Group C 1 patient had an overall rise in her FEV1 (maximal rise 10%) while 6 patients had falls (mean maximal % fall 22 +/- 7). In all groups the heart rate increased in response to betelnut. Betelnut chewing caused bronchoconstriction as demonstrated by decreases in FEV1 in a majority of the asthmatic patients studied; hence betelnut may act as a trigger factor for their asthma. In a few others increases in FEV1 were noted, while the rest experienced only minor changes.