Fatty acid levels and risk of asthma in young adults.
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 gamma-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).


CONCLUSIONS
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.
Woods
R K
RK
Department of Epidemiology and Preventive Medicine, Central and Eastern Clinical School, Monash University and The Alfred Hospital, Melbourne, Victoria 3004, Australia.
Raven
J M
JM
Walters
E H
EH
Abramson
M J
MJ
Thien
F C K
FC
D000328:Adult; D001249:Asthma / Q000097:blood* / Q000209:etiology / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000097:blood / Q000209:etiology; D003430:Cross-Sectional Studies; D005227:Fatty Acids / Q000008:administration & dosage / Q000097:blood*; D005260:Female; D005395:Fish Oils / Q000008:administration & dosage; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D011379:Prognosis; D012307:Risk Factors
D005227:Fatty Acids; D005395:Fish Oils