Childhood PUFA levels in relation to allergic sensitization and rhinitis up to young adulthood.

Background: Very long-chain (VLC) polyunsaturated fatty acids (PUFA) have been hypothesized to influence the risk of allergic disease. The aim of the study was to investigate the role of plasma levels of omega-3 (n-3) and omega-6 (n-6) PUFA in childhood and adolescence, for the development of rhinitis and allergic sensitization up to young adulthood.

Methods: The study included n = 933 participants from the BAMSE cohort. Proportions of n-3 and n-6 PUFA in plasma phospholipids were analyzed at 8 and 16 years using gas chromatography. Associations between PUFA and rhinitis as well as allergic sensitization, analyzed by IgE reactivity against airborne allergens, up to age 24 years were analyzed by generalized estimating equations and logistic regression models.

Results: High plasma levels of VLC n-3 PUFA as well as the n-6 PUFA arachidonic acid (AA) at 8 years were inversely associated with rhinitis (overall OR up to 24 years: 0.72, 95% CI 0.55, 0.0.93 and 0.69 [0.53, 0.89], respectively) and aeroallergen sensitization (0.64 [0.49, 0.83] and 0.71 [0.54, 0.92], respectively). However, excluding prevalent cases at 8 years attenuated the associations.

Conclusion: Plasma levels of n-3 and certain n-6 PUFA in childhood were inversely associated with allergic sensitization and allergic rhinitis up to young adulthood. The association may to some extent be explained by persistent childhood disease, rather than new incident cases in adolescence and young adulthood. To what extent these associations are driven by dietary PUFA intake versus metabolism remains to be clarified for the prevention of rhinitis and allergic sensitization.