Phase I Clinical Study of the Dietary Supplement, Agaricus blazei Murill, in Cancer Patients in Remission. Evidence-Based Complementary and Alternative Medicine. 2011;2011:192381.
Rationale
Agaricus blazei Murill is one of the most popular "medicinal" mushrooms in the oncology population: patients in remission often take it on their own as a supplement. Yet a systematic clinical safety assessment — especially in the vulnerable post-treatment group — was missing. This phase I study addresses exactly that: not efficacy, but tolerability and laboratory safety across doses.
Methods
An open-label phase I study with cohort dose escalation. 78 patients in remission after cancer treatment took granulated A. blazei powder (Kyowa Wellness, Tokyo) orally for 6 months:
- 30 patients — 1.8 g/day (1 sachet);
- 24 patients — 3.6 g/day (2 sachets);
- 24 patients — 5.4 g/day (3 sachets).
Adverse events were graded by subjective and objective symptoms plus laboratory data per NCI-CTCAE v3.0.
Results
- Adverse events were recorded in 9 of 78 patients (12%).
- Most were digestive: nausea, diarrhea.
- One patient developed liver dysfunction assessed as a food allergy (drug lymphocyte product).
- No dose dependence of AEs — event frequency did not rise from 1.8 to 5.4 g/day.
Conclusions
The authors conclude that granulated A. blazei powder at studied doses up to 5.4 g/day for 6 months causes no laboratory problems in most patients and is generally safe — apart from a possible allergic reaction (including the single liver-dysfunction case).
Worth noting
Strengths: long for phase I (6 months), dose escalation with adequate cohorts, standardized AE grading (NCI-CTCAE), a clinically vulnerable population — the people who actually buy the supplement.
Limitations:
- Open-label, no placebo — the background rate of GI symptoms in this population is not subtracted; "12% AEs" cannot be compared against control.
- Remission population — results do not transfer to patients in active treatment or to healthy people.
- One manufacturer, one form — granules from a specific factory; extracts and powders from elsewhere may have different impurity profiles.
- Allergic signal — the single liver-reaction case remains a signal for people with allergy history; the sample is not powered for rare AEs.