Symptom improvements and adverse effects with Reishi mushroom use: A Cross-Sectional survey of cancer patients

Background: Reishi, a medicinal mushroom, is increasingly used for symptom control by cancer patients worldwide. However, data around patients' experiences with Reishi in oncology are lacking, limiting safe, effective clinical applications. We thus sought to evaluate patient reported benefits and harms of using Reishi.

Methods: We conducted a cross-sectional survey among Chinese cancer patients using Reishi products, probing for symptom improvements and/or adverse events (AEs) after taking Reishi. Multivariable logistic regression models assessed whether socio-demographic or clinical factors, as well as duration of Reishi use or combination with other TCM herbs, were associated with being a "responder" - reporting "quite a bit" or "very much" symptom improvement.

Results: Among 1374 participants, more than half of participants reported that nausea (55 %), fatigue (52 %), poor appetite (51 %), and depression (50 %) improved quite a bit or very much after taking Reishi. In multivariate analyses, age <65 years (adjusted odds ratios [AOR] = 1.76, p = 0.001), diagnosis ≥ 10 years (AOR = 1.78, p = 0.018), and duration of Reishi use ≥ 1 year (1-3 years: AOR = 1.53, p = 0.045; 3-5 years: AOR = 2.04, p = 0.001; >5 years: AOR = 2.07, p < 0.001) were significantly associated with higher responder rates for symptom improvement. However, 125 (9.1 %) also reported a range of AEs, including dry mouth (5 %), constipation (4 %), insomnia (3 %), pruritus (3 %) and vertigo (3 %).

Conclusion: While majority of cancer patients using Reishi reported symptom improvements, some reported adverse effects. This information can assist clinicians in advising cancer patients on safe and effective use of Reishi and help identify specific outcomes for assessment in future prospective clinical trials.