OBJECTIVE:
It remains uncertain whether intake of fish or n-3 polyunsaturated fatty acids is preventive against allergic disorders. This cross-sectional study investigated the association of intake of selected high-fat foods and specific types of fatty acids with the prevalence of allergic rhinitis in Japan where intake of fish is high.

METHODS:
Study subjects were 1002 Japanese pregnant females. Allergic rhinitis (including cedar pollinosis) was defined as present if subjects had received drug treatment at some point during the previous 12 months. Information on dietary factors was collected using a validated self-administered diet history questionnaire. Adjustment was made for age, gestation, parity, cigarette smoking, passive smoking at home and at work, indoor domestic pets, family history of asthma, atopic eczema, and allergic rhinitis, family income, education, mite antigen level in house dust, changes in diet in the previous month, season when data were collected, and body mass index.

RESULTS:
There was a tendency for an inverse dose-response association between fish intake and allergic rhinitis although the adjusted odds ratio for comparison of the highest with the lowest quartile was not statistically significant (p for trend = 0.09). Intake of eicosapentaenoic and docosahexaenoic acids was independently associated with a decreased prevalence of allergic rhinitis: the multivariate odds ratio for the highest quartile was 0.56 (95% confidence interval: 0.32-0.96, p for trend = 0.03). Intake of n-6 polyunsaturated fatty acids in the third quartile but not the second and fourth quartiles showed a tendency for an inverse association with the prevalence of allergic rhinitis. No measurable relationship was found between consumption of meat, eggs, dairy products, total fat, saturated, monounsaturated, and n-3 polyunsaturated fatty acids, and cholesterol or the ratio of n-3 to n-6 polyunsaturated fatty acids and allergic rhinitis.

CONCLUSION:
Our findings suggest that the intake of eicosapentaenoic and docosahexaenoic acids may be associated with a reduced prevalence of allergic rhinitis.