The inability to smell things after a SARS-CoV-2 infection has been attributed to neuroinflammatory events within the olfactory bulb and the central nervous system.
Thus, targeting neuroinflammation is one potential strategy for promoting recovery from post-COVID-19 chronic olfactory dysfunction.
Palmitoylethanolamide (PEA) and luteolin are candidate anti-inflammatory and neuroprotective agents.
This placebo-controlled, randomized study investigated olfactory function in patients treated with PEA plus Luteolin oral supplements plus olfactory training versus placebo plus olfactory training. The supplements and training were provided for 90 days.
The study participants had persistent olfactory impairment >6 months after follow-up SARS-CoV-2 negative testing, without prior history of olfactory dysfunction or other sinus disorders.
The results showed that the intervention group had significantly greater improvement in olfactory threshold, discrimination, and identification scores compared to controls.
Overall, 92% of patients in the intervention group improved versus 42% of controls.
References:
Di Stadio, Arianna, et al. “Ultramicronized Palmitoylethanolamide and Luteolin Supplement Combined with Olfactory Training to Treat Post-COVID-19 Olfactory Impairment: A Multi-Center Double-Blinded Randomized Placebo-Controlled Clinical Trial.” Current Neuropharmacology, vol. 20, no. 10, Aug. 2022, pp. 2001–12. PubMed Central, https://doi.org/10.2174/1570159X20666220420113513.