Fatty acid levels and risk of asthma in young adults
- 1Department of Epidemiology and Preventive Medicine, Central and Eastern Clinical School, Monash University and The Alfred Hospital, Melbourne, Victoria 3004, Australia
- 2Department of Allergy, Immunology and Respiratory Medicine, Central and Eastern Clinical School, Monash University and The Alfred Hospital, Melbourne, Victoria 3004, Australia
- 3Discipline of Medicine, School of Medicine, University of Tasmania, Hobart, Tasmania 7000, Australia
- Correspondence to:
Assoc Professor F C K Thien
Department of Allergy, Immunology and Respiratory Medicine, Monash University, Central and Eastern Clinical School, The Alfred Hospital, Commercial Road, Melbourne, Victoria 3004, Australia;
- Received 4 May 2003
- Accepted 8 October 2003
Background: There is current interest in the possible protective effect of long chain (n-3) fatty acids from fish in chronic lung diseases such as asthma. The aim of this community based cross sectional study was to determine whether plasma long chain (n-3) fatty acids, as a measure of dietary intake, differed between 1601 young adults with and without asthma.
Methods: Subjects of mean (SD) age 34.6 (7.1) years completed a detailed respiratory questionnaire, food frequency questionnaire, skin prick testing, and lung function tests including methacholine challenge test for bronchial hyperreactivity (BHR) and had venous blood taken for analysis of plasma fatty acids. Plasma fatty acid levels (%) were analysed using multiple logistic regression with alternative definitions of asthma and atopy as the outcomes.
Results: Atopy was not associated with any plasma fatty acid. The n-3 polyunsaturated fatty acids and n-6:n-3 ratio were not consistently associated with asthma or atopy. The n-6 polyunsaturated fatty acid dihomo γ-linolenic acid (DHGLA) was positively associated with current asthma (OR = 1.30, 95% CI 1.06 to 1.60), asthma (OR = 1.34, 95% CI 1.13 to 1.60), and doctor diagnosed asthma (OR = 1.25, 95% CI 1.06 to 1.48).
Conclusion: Plasma n-3 fatty acids are not associated with a reduced risk of asthma or atopy among young adults. The association of DHGLA with asthma warrants further research to determine a cause-effect relationship.
- AA, arachidonic acid
- BHR, bronchial hyperreactivity
- DHA, docosahexaenoic acid
- DHGLA, dihomo γ-linolenic acid
- DPA, docosapentaenoic acid
- EPA, eicosapentaenoic acid
- FEV1, forced expiratory volume in 1 second
- GLA, γ-linolenic acid
- LA, linoleic acid
- LNA, α-linolenic acid
This study was funded by the National Health and Medical Research Council of Australia (NHMRC) and the Victorian Health Promotion Foundation (VicHealth). Dr Rosalie Woods held an NHMRC post-doctoral Public Health fellowship (#987087). None of the study sponsors had any involvement in the study design; collection, analysis and interpretation of data; in the writing of the report; or in the decision to submit the report for publication.