The effect of perinatal omega-3 fatty acid supplementation on inflammatory markers and allergic diseases: a systematic review

Abstract

Background: Maternal supplementation with omega-3 polyunsaturated fatty acids (n-3 PUFA) may modulate immune responses and allergy in neonates and children.

Objective: To determine if n-3 PUFA supplementation during pregnancy and lactation reduces risk for childhood allergic disease.

Search strategy: We searched Medline and all evidence-based medicine reviews for randomised controlled trials comparing the effects of n-3 PUFA and placebo supplementation during pregnancy and/or lactation on childhood allergic diseases and inflammatory cytokines.

Selection criteria: We included studies reporting on food allergy, response to the egg skin prick test (SPT), atopy and asthma in infancy and childhood as well as production of interleukin-13 and interferon-gamma, two cytokines involved in the pathogenesis of asthma. For assessment of inclusion, two authors reviewed all abstracts for suitability and independently extracted data.

Data collection and analysis: Two-by-two tables were constructed and odds ratios (OR) were calculated for the outcomes: response to the SPT, food allergy, atopy and asthma in childhood. The assays differed so data on inflammatory markers were reported in narrative form.

Main results: Five randomised controlled trials (n = 949) were included. n-3 PUFA supplementation during pregnancy reduced 12-month prevalence of positive egg SPT (two trials, 12/87 versus 32/100, OR 0.33, 95% CI 0.16, 0.70) and childhood asthma (two trials, 10/303 versus 17/179, OR 0.349, 95% CI 0.154, 0.788) and significantly reduced cord blood interleukin-13 levels. Supplementation during lactation did not prevent asthma, food allergy or atopy.

Conclusion: n-3 PUFA supplementation during pregnancy decreases childhood asthma and response to SPT.