Multidimensional clinical benefits of cinnamon leaf oil inhalation in primary and metastatic brain tumor patients during winter: A randomized controlled trial.

OBJECTIVE: To evaluate the multidimensional efficacy of 12‑week cinnamon leaf oil (CLO) inhalation as a seasonal adjuvant supportive‑care intervention for alleviating winter‑exacerbated non‑motor symptom burden and improving mood disorders, sleep quality, refractory fatigue, and functional independence in patients with primary and metastatic brain tumors.

METHODS: This randomized, controlled clinical trial enrolled 328 patients diagnosed with primary or metastatic brain tumors, randomly assigned at a 1:1 ratio to intervention group (standard antitumor care plus 12‑week undiluted CLO inhalation, 2 h/day, 5 days/week, n = 165) or control group (standard care plus distilled‑water‑vapor sham‑aromatherapy control, n = 163). Baseline demographic and clinical characteristics were descriptively summarized for both groups. The primary outcome was the change in HAM-D total score from baseline to week 12. Secondary outcome indicators included changes in anxiety (HAM‑A), sleep quality (PSQI), physical/mental fatigue (FS-14), and activities of daily living (ADL-BI). Integrated multidimensional outcome profiling was further performed to examine changes across six clinical domains.

RESULTS: Twelve weeks of CLO inhalation was associated with improvements across the assessed outcome measures, whereas the control group receiving only standard care showed minimal clinical changes. The intervention group showed reductions in emotional symptoms, with HAM‑A scores decreasing from 17.65 ± 4.48-12.25 ± 4.51 (p < 0.001) and HAM‑D scores declining from 22.10 ± 5.41-13.68 ± 2.71 (p < 0.001). Improvements in sleep quality were observed, with PSQI total scores dropping from 12.18 ± 3.05-5.25 ± 1.86 (p < 0.01). Additionally, the CLO group showed changes in functional independence, with ADL‑BI total scores increasing from 63.60 ± 14.16-74.88 ± 11.33 (p < 0.01). In terms of fatigue relief, the proportions of patients with severe physical and mental fatigue decreased by 46% and 76%, respectively (p < 0.01). Multidimensional profiling indicated favourable changes for CLO inhalation across sleep, anxiety, depression, physical fatigue remission, mental fatigue remission and daily function. Only mild Grade 1 transient mucosal irritation adverse events occurred in the intervention group with low incidence; no severe adverse reactions or trial withdrawal were observed.

CONCLUSION: Findings from this single‑centre trial suggest that 12‑week standardized CLO inhalation may represent a tolerable non‑pharmacological adjuvant approach for brain tumour patients. It was associated with reductions in winter‑exacerbated anxiety, depression, sleep disturbance, and refractory fatigue, as well as improvements in patients' functional independence. Observations of multi‑domain symptom changes warrant further clinical investigation to evaluate its utility within neuro‑oncological supportive‑care practice and patients' long‑term quality‑of‑life outcomes.