Dietary patterns and asthma in the E3N study.

The aim of the present study was to determine dietary patterns and investigate their association with asthma incidence, current asthma and frequent asthma exacerbations. Dietary habits and asthma data were collected from the large E3N study (of French females, mostly teachers). Of the 54,672 females followed-up in 2003, 2,634 reported ever-adulthood asthma, 1,063 reported current asthma, 206 reported frequent asthma attacks (one or more a week), and 628 reported asthma onset between 1993 and 2003. Using principal component analysis, three dietary patterns were identified: the "prudent" pattern (fruits and vegetables); the "Western" pattern (pizza/salty pies, dessert and cured meats); and the "nuts and wine" pattern. Pattern scores were categorised into tertiles, and the incidence and prevalence of asthma was compared between tertiles. After adjustment for confounders, no association of dietary patterns was observed with asthma incidence, ever-asthma or current asthma. The Western pattern was associated with an increased risk of reporting frequent asthma attacks (highest versus lowest tertile odds ratio (OR) 1.79, 95% confidence interval (CI) 1.11-3.73). Increasing scores of the nuts and wine pattern were associated with a decreased risk of reporting frequent asthma attacks (highest versus lowest tertile OR 0.65, 95% CI 0.31-0.96). The results of the present study suggest that overall diet could be involved in frequent asthma exacerbations, one aspect of asthma severity.