Experimental groups
The four study groups were defined as follows:Combined therapy (um-PEA–LUT: once daily + olfactory training): These patients received daily treatment with one sachet of orally administered co-ultra-micronized Palmitoylethanolamide 700 mg and Luteolin 70 mg (GlialiaUm-PEA–LUT alone (once daily): These patients received once daily treatment with one sachet of um-PEA–LUT, administered 5–10 min before breakfast for 90 days.Um-PEA–LUT alone (twice daily): These patients received twice daily treatment with one sachet of um-PEA–LUT administered 5–10 min before breakfast and one sachet of um-PEA–LUT administered 5–10 min before lunch for 90 days.Olfactory Training plus placebo supplement (control): These patients received olfactory training using the same regimen as in the combined therapy group above plus a daily placebo supplement therapy (generic multivitamin).All patients performed the olfactory training independently at home after receiving in-person detailed education and practical training, as overseen by the physician. The initial education consisted of a face-to-face explanation on how to perform olfactory training followed by practice performing the exercise until competency was verified. In addition, a written description on how to prepare the essences was provided. This instruction was reinforced by providing access to an instructional video, which provides detailed instruction on how to perform the basic steps of olfactory training (All patients (including the control group and the three therapeutic intervention groups) underwent the following nasal endoscopic examination at 