Enhancement of the Th1-Phenotype Immune System by the Intake of Oyster Mushroom (Tamogitake) Extract in a Double-Blind, Placebo-Controlled Study

Authors:
Aiko Tanaka, Mie Nishimura, Yuji Sato, Hiroki Sato, Jun Nishihira

Journal:
Journal of Traditional and Complementary Medicine, 2016
DOI: 10.1016/j.jtcme.2015.11.004

Study Design

8-week randomized, double-blind, placebo-controlled clinical trial

Participants

47 healthy Japanese adults (age 34–64), randomized to either a test group (n=20) consuming oyster mushroom extract or a placebo group (n=21). Six were excluded before the trial due to noncompliance or disqualifying health conditions.

Intervention

Daily consumption of 80 mL of water-extracted Pleurotus cornucopiae (Tamogitake) mushroom (24 mg β-glucan per dose) or a placebo beverage for 8 weeks.

Outcome Measures

• Plasma cytokine levels: IFN-γ, IL-12, TNF-α, IL-10, IL-13, IL-4, IL-5
• Natural killer (NK) cell activity
• Blood biomarkers: CBC, liver, renal, lipid, and glucose profiles
• Subjective well-being (visual analog scale)

Summary

This trial examined the immunomodulatory effects of Tamogitake (Pleurotus cornucopiae) mushroom extract in healthy adults. After 8 weeks, IFN-γ significantly increased in the mushroom group (p = 0.013), with a modest rise in IL-12, suggesting activation of Th1-type immune responses. No significant change was observed in Th2 cytokines (IL-4, IL-10, IL-13). NK cell activity increased slightly but not significantly. No adverse effects or negative shifts in blood chemistry were reported, confirming the supplement’s safety. The findings suggest oyster mushroom extract may support cellular immunity by enhancing Th1 cytokine activity, particularly IFN-γ production.