Calorie controlled diet for chronic asthma.

backgroundThe prevalence of asthma has increased in recent years. Epidemiological studies suggest a correlation between the onset of asthma and dietary nonallergic factors especially high calorie diet. These can be regarded as other potentially important risk factors.

objectivesTo observe the effect of dietary calorie reduction on chronic asthma in adults or children. SEARCH STRATEGY: We searched the Cochrane Airways Group trials register using prespecified terms. We assessed bibliographies from included studies, and contacted authors of known studies for additional information about published and unpublished trials. Date of most recent search: May 2004 SELECTION CRITERIA: Randomised-controlled trials of dietary calorie reduction were included. DATA COLLECTION AND ANALYSIS: Three authors assessed each study independently. Disagreement was resolved by consensus. Quality assessment was performed independently. MAIN

resultsOne trial of fair methodological quality with a total of 38 patients suffering from chronic asthma was included. There were significant increases in FEV(1) and FVC in the active treatment group compared with control. No data pertaining serious adverse effects were reported from the interventions. AUTHORS'

conclusionsThere is currently a very small amount of evidence assessing the effects of dietary interventions intended as part of a wide-ranging weight-loss programme. Whilst we are unable to recommend these strategies as concomitant interventions with drug-based therapy for the specific management of asthma, dietary interventions such as weight-loss programmes may provide benefits in specific patients. However, the impact of a calorie-controlled diet on the signs and symptoms of asthma in the general asthmatic population is yet to be established.