Omega-3 Fatty Acid Supplementation for the Treatment of COVID-19-Related Olfactory Dysfunction

ABSTRACT

Introduction: Olfactory dysfunction (OD) is a prevalent and characteristic symptom among individuals with COVID-19 infection. Although most patients with COVID-19-related OD experience a significant recovery, there exists a substantial population of patients with persistent OD with limited therapeutic options. Method(s) Patients with laboratory-confirmed or clinically suspected COVID-19 infection and self-reported new onset OD from March 2020 to October 2021 were prospectively recruited for a randomized, placebo-controlled, doubleblinded clinical trial. Patients with evidence of quantitative OD, defined as a Brief Smell Identification Test (BSIT) score of 9 or less, were eligible for study inclusion. The experimental group received 2 g of omega-3 fatty acid (O3FA) supplementation, including 1366-mg eicosapentaenoic acid and 504-mg docosahexaenoic acid, while the control group received an identical placebo, each to be taken daily for 6 weeks. The primary outcome was change in BSIT score from initial test to a 6-week follow-up BSIT. Result(s) A total of 117 patients were included in analysis, including 57 patients in the O3FA group and 60 in the placebo group. The mean duration of OD prior to study enrollment was 200.1 days with no significant difference between groups (P=.685). Patients receiving O3FA supplementation demonstrated a mean BSIT improvement of 1.12+/-1.99 compared with 0.68+/-0.86 in the placebo group (P=.385). Among those with severe hyposmia, defined as a BSIT score of 7 or less, patients in the O3FA group (n=23) demonstrated a BSIT improvement of 2.30+/-0.77 compared with 1.63+/-1.82 among those in the placebo group (n=16, P=.255). Conclusion(s) Our study showed a trend toward improved olfactory recovery among COVID-19-related OD patients receiving high doses of O3FA supplementation at a 6-week follow-up time point. Future work will be needed to better define the effectiveness and durability of O3FA supplementation as a treatment for COVID-19-related OD.