Present address R. L. Thompson, World Cancer Research Fund International, 19 Harley Street, London W1G 9QJ, UK.
Dietary patterns and adult asthma: population-based case–control study
Article first published online: 20 OCT 2009
© 2009 John Wiley & Sons A/S
Volume 65, Issue 5, pages 606–615, May 2010
How to Cite
Bakolis, I., Hooper, R., Thompson, R. L. and Shaheen, S. O. (2010), Dietary patterns and adult asthma: population-based case–control study. Allergy, 65: 606–615. doi: 10.1111/j.1398-9995.2009.02215.x
Edited by: Marc Humbert
- Issue published online: 1 APR 2010
- Article first published online: 20 OCT 2009
- Accepted for publication 28 April 2009
- dietary patterns;
- principal components analysis
To cite this article: Bakolis I, Hooper R, Thompson RL, Shaheen SO. Dietary patterns and adult asthma: population-based case–control study. Allergy 2010; 65: 606–615.
Background: Epidemiological studies of diet and asthma have focused on relations with intakes of individual nutrients and foods and evidence has been conflicting. Few studies have examined associations with dietary patterns.
Methods: We carried out a population-based case–control study of asthma in adults aged between 16 and 50 in South London, UK. Information about usual diet was obtained by food frequency questionnaire and we used principal components analysis to define five dietary patterns in controls. We used logistic and linear regression, controlling for confounders, to relate these patterns to asthma, asthma severity, rhinitis and chronic bronchitis in 599 cases and 854 controls.
Results: Overall, there was weak evidence that a ‘vegetarian’ dietary pattern was positively associated with asthma [adjusted odds ratio comparing top vs bottom quintile of pattern score 1.43 (95% CI: 0.93–2.20), P trend 0.075], and a ‘traditional’ pattern (meat and vegetables) was negatively associated [OR 0.68 (0.45–1.03), P trend 0.071]. These associations were stronger amongst nonsupplement users (P trend 0.030 and 0.001, respectively), and the association with the ‘vegetarian’ pattern was stronger amongst whites (P trend 0.008). No associations were observed with asthma severity. A ‘prudent’ dietary pattern (wholemeal bread, fish and vegetables) was positively associated with chronic bronchitis [OR 2.61 (1.13–6.05), P trend 0.025], especially amongst nonsupplement users (P trend 0.002).
Conclusions: Overall there were no clear relations between dietary patterns and adult asthma; associations in nonsupplement users and whites require confirmation. The finding for chronic bronchitis was unexpected and also requires replication.