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Evidence-Based Supplement Research
Evidence-Based Supplement Research

Therapeutic effect of anti-neuroinflammatory supplement combined with olfactory training on post-covid olfactory dysfunction: a systematic review and meta-analysis.

  • 2026-01-20
  • European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery 283(6)
    • Ya Shi
    • Bin Li
    • Yun Zheng
    • Caiping Xue
    • Jun Zhu

Study Design

Type
Meta-Analysis
Sample size
n = 525
Population
525 patients with post-COVID olfactory dysfunction (PCOD)
Methods
Meta-analysis of 7 RCTs comparing PEA-LUT combined with olfactory training vs olfactory training alone

Background

There is no established specific treatment for post-COVID olfactory dysfunction (PCOD) currently. Olfactory training (OT) is the only effective intervention supported by clinical evidence. The anti-neuroinflammatory supplement palmitoylethanolamide and luteolin (PEA-LUT) has shown potential in alleviating the symptoms of post-COVID, but its therapeutic effect on olfactory dysfunction and the gain effect when combined with OT remain to be evaluated.

Methods

We comprehensively searched the online databases EMBASE, PubMed, ScienceDirect, Web of Science, Cochrane Library, Google Scholar, and ClinicalTrials.govfor the literature related to the treatment of PCOD, identified studies reporting the efficacy of PEA-LUT combined with OT, extracted the treatment outcome data, and performed data synthesis.

Results

A total of 7 eligible RCTs published between 2021 and 2024 were included, comprising 525 patients with PCOD. Of the seven studies, five (71.4%) used the full Threshold-Discrimination-Identification (TDI) scoresystem to assess olfactory function, while two (28.6%) used only the Identification ("I") subscale; 332 patients (63.2%) received PEA-LUT + OT therapy and 203 (38.8%) received OT alone. Meta-analysis of these studies showed that patients receiving PEA-LUT combined with OT had significantly higher TDI scores compared to those receiving OT alone (Standard mean difference (SMD) = 0.90; 95% CI: 0.24-1.58; P < 0.01). The overall response rate was also significantly higher in the combination group (Risk difference (RD) = 0.33; 95% CI: 0.01-0.64; P = 0.04).

Conclusion

The neuroprotective properties of PEA-LUT appear to enhance recovery from post-COVID olfactory dysfunction. When combined with olfactory training, this treatment shows promising potential as a novel therapeutic approach.

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