Is diet responsible for the high asthma prevalence amongst adult Australians?
Professor Michael Abramson
Dr Rosalie Woods
Dr Frank Thien
Dr Paul Ireland
Professor Haydn Walters
Funded by: NHMRC
This study commenced in 1998 and was designed to look at the prevalence and risk factors, particularly dietary factors, associated with respiratory health in young adults. A total of 3194 brief respiratory questionnaires were returned from 4456 adults aged between 20 and 44 years who were randomly selected from the electoral roles. Thus a response rate of 72% was achieved. The results have shown that the prevalence of having asthma ever, doctor-diagnosed asthma and currently using asthma medications has increased significantly since 1990. The second phase of the study, which involved participants coming to our laboratory for some simple breathing and allergy tests and giving information on their usual diet has now been completed. A total of 1601 completed the respiratory questionnaire, 1469 completed the food frequency questionnaire, 1141 completed skin prick and lung function testing and 1075 completed the methacholine challenge for non-specific bronchial hypreresponsiveness. We are now in the process of analyzing these results. It is anticipated that results from this study will become available over the next 12 months.
We have found that the prevalence of current asthma among young adults in Melbourne has not changed between 1992 (prevalence=17.2%, 95% confidence intervals=14.1-20.8%) and 1999 (prevalence=16.7%, 95% confidence intervals=14.6-19.1%, p=0.8).