Omega-3 polyunsaturated fatty acid supplementation for the management of exercise-induced bronchoconstriction: a systematic review and meta-analysis

Background Omega-3 polyunsaturated fatty acid (PUFA) supplementation is often cited as a non-pharmacological strategy for the management of exercise-induced bronchoconstriction (EIB); however, evidence remains inconsistent. Methods We conducted a systematic review and meta-analysis in accordance with PRISMA guidelines to evaluate the efficacy of omega-3 PUFA for the management of EIB. Studies including adults with EIB receiving omega-3 PUFA supplementation (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) compared with placebo were included. The primary outcome was the post-challenge decline in FEV 1 following indirect bronchial provocation. Random-effects meta-analysis was performed using standardised mean differences (SMD) with 95% CIs. Results Eight studies (n=141 adults with EIB) met the inclusion criteria, of which six were included in the meta-analysis (n=106). Omega-3 PUFA supplementation was associated with attenuation of the post-challenge decline in FEV 1 (SMD=−0.96, [95% CI: −1.84 to −0.08]); however, substantial heterogeneity was observed (I 2 =87%), and the pooled estimate should therefore be interpreted with caution. Subgroup analyses demonstrated a greater apparent effect in studies employing exercise challenge (SMD=−1.54, [95% CI: −3.55 to −0.48]) compared with eucapnic voluntary hyperpnoea (SMD=−0.60, [95% CI: −1.31 to 0.12]). Conclusions Omega-3 PUFA supplementation does not provide a consistent clinical benefit in EIB. While modest attenuation of airway narrowing is reported in some cohorts, effects are heterogeneous and not reproducible. Where benefit is observed, it appears to coincide with suppression of lipid-derived inflammatory mediators, suggesting a potential endotype-specific mechanism. These findings indicate limited utility in unselected populations and support further precision-based trials.