- Ling zhi
- lin zi
- mushroom of immortality
For Patients & Caregivers
Bottom Line: Reishi mushroom has antioxidant properties and may enhance immune response.
Reishi mushroom contains complex sugars known as beta-glucans that may stop the growth and prevent spread of cancer cells. When animals were fed beta-glucans, some cells of their immune system become more active. Limited data from clinical studies suggest reishi can strengthen immune response in humans. In addition, reishi mushrooms contain sterols that can act as precursors to hormones in the body, along with substances called triterpenes that may have blood pressure-lowering and anti-allergy (anti-histamine) effects. Reishi mushrooms have also been shown to slow the process of blood clotting.
Reishi mushroom can cause toxicity in some immune cells. More studies are needed to show that it is safe and effective for cancer treatment.
- To treat fatigue
No scientific evidence supports this use.
- To lower high cholesterol
There are no data to back this claim.
- To treat HIV and AIDS
Laboratory studies suggest that reishi mushroom may stimulate certain cells of the immune system, but evidence is lacking on reishi’s ability fight infections.
- To lower high blood pressure
Laboratory studies suggest that reishi mushroom may lower blood pressure. Human studies are lacking.
- To stimulate the immune system
Laboratory studies suggest that reishi mushroom may stimulate some cells of the immune system. A small clinical trial showed that reishi can enhance immune response in advanced-stage cancer patients. More studies are needed.
- To reduce inflammation
Laboratory studies suggest that reishi mushroom may have antihistamine effects. This has not been tested in humans.
- For increased strength and stamina
No scientific evidence supports this use.
Lower Urinary Tract Symptoms (LUTS)
LUTS is common in older men and usually involves problems with bladder filling or voiding. In a randomized, placebo-controlled clinical study, 88 men with slight-to-moderate LUTS were given a reishi extract (6 mg daily) or placebo for 12 weeks. Reishi extracts improved LUTS more than the placebo. Also, no severe adverse effects were reported. Larger, long-term studies are needed to see if reishi extracts can improve urinary flow in men with more severe LUTS.
- You are taking warfarin or other blood thinners: Reishi may increase the risk of bleeding.
- You are on chemotherapy: Reishi may make some chemotherapy drugs less effective.
- You are using immunosuppressants: Reishi can stimulate immune responses.
- If you are taking drugs that are substrates of Cytochrome P450 2E1, 1A2, and 3A: Reishi may increase the risk of side effects of these drugs.
Two cases of liver toxicity, resulting in death in one case, have been reported with use of powdered reishi mushroom.
A case of chronic diarrhea was reported in a 49-year-old man with non-Hodgkin’s lymphoma following long-term use of a powdered extract of reishi mushroom.
A case of one patient who had ingested reishi mushrooms for a long time, who was mistakenly treated for a particular parasite because both can share a similar structure in lab specimens.
For Healthcare Professionals
Reishi mushroom is a fungus that holds an important place in the traditional medical systems of China, Japan, Korea and other Asian countries for its health-promoting effects. It is used as an immunostimulant by patients with HIV and cancer. The active constituents include both beta-glucan polysaccharides and triterpenes.
Extracts of reishi were shown to have immunomodulatory (2)(3)(4)(5)(12), renoprotective (9), anti-inflammatory (36), and hepatoprotective (37) properties both in vitro and in vivo. Clinical studies indicate its benefits in improving lower urinary tract symptoms (LUTS) in men (10)(20), and in exerting mild antidiabetic effects and improving dyslipidemia (29). However, randomized controlled trials do not support the use of reishi to address cardiovascular risk factors associated with type 2 diabetes (38).
Reishi has also been studied for its anticancer potential. In vitro and animal studies indicate that it has antiproliferative(39) and chemopreventive effects (21), alleviates chemotherapy-induced nausea (13), enhances the efficacy of radiotherapy (22), and increases the sensitivity of ovarian cancer cells to cisplatin (27). It may also help prevent cisplatin-induced nephrotoxicity (28).
In small clinical studies, reishi increased plasma antioxidant capacity (6)(7), and enhanced immune responses in cancer patients (8)(40). In another study, a water-soluble reishi extract appeared to suppress development of colorectal adenomas (41). Remission of hepatocellular carcinoma (HCC) was reported in a few cases in a single study (23). Another case study series suggests benefits for gastrointestinal cancer patients (42). However, further research is needed to establish use of reishi as an anticancer agent (30).
An in vitro study reported that reishi mushroom extract has toxic effects in leukocytes (14). Therefore, more research is needed to determine its safety and effectiveness as an adjunctive cancer treatment.
Beta glucans, polysaccharides present in reishi, have demonstrated antitumor and immunostimulating activities (18)(40). Its triterpene compounds may inhibit tumor invasion by reducing matrix metalloproteinase expression (16), and tumor metastases by limiting attachment to endothelial cells (17). Recent findings indicate that reishi induces natural killer (NK) cell cytotoxicity against various cancer cell lines via activation of the natural cytotoxic receptors (NKG2D/NCR) and mitogen-activated protein kinase (MAPK)-signaling pathways, which result in exocytosis of perforin and granulysin (31). Reishi polysaccharides were also shown to increase expression of the major histocompatibility (MHC) class I and costimulatory molecules on melanoma cells, resulting in enhanced antitumor cytotoxicity (32). In human ovarian cancer cells, reishi inhibits proliferation by suppressing vascular endothelial growth factor (VEGF) expression and upregulating connexin 43 expression (39).
In other studies reishi increased plasma antioxidant capacity (6)(7) and enhanced immune response in advance-stage cancer patients (8). Its extracts also inhibited 5-alpha reductase, an important enzyme that converts testosterone to dihydrotestosterone and is upregulated in benign prostatic hyperplasia (9).
- Two cases of hepatoxicity, leading to death in one case, have been reported with use of powdered reishi mushroom (24)(25).
- A case of chronic diarrhea was reported in a 49-year-old man with non-Hodgkin’s lymphoma following prolonged consumption of powdered extract of reishi mushroom (26).
- A case of pseudoparasitosis due to similarity in structure with Clonorchis sinensis ova, in a patient who had long-term ingestion of reishi mushrooms.(39)
- Anticoagulants / Antiplatelets: Reishi may increase the risk of bleeding (12).
- Immunosuppressants: Reishi can enhance immune response (8).
- Chemotherapeutic Agents: Reishi can increase plasma antioxidant capacity, and in theory, can interact with chemotherapeutic agents that rely on free radicals (6).
- Cytochrome P450 substrates: Reishi polysaccharides inhibit CYP2E1, CYP1A2, and CYP3A, and can affect the intracellular concentration of drugs metabolized by these enzymes (15).
Noguchi M, et al. Randomized clinical trial of an ethanol extract of Ganoderma lucidum in men with lower urinary tract symptoms. Asian J Androl. Sep 2008;10(5):777-785.
Because G. lucidum extracts have shown variable 5 alpha-reductase inhibition, 88 men with slight-to-moderate lower urinary tract symptoms (LUTS) were given G. lucidum extract 6 mg daily that maximally inhibited 5 alpha-reductase or placebo for 12 weeks. Improvements in LUTS as assessed by the International Prostate Symptom Score (IPSS) and urine flow variables were determined. In addition, prostate volume, residual urinary volume after voiding, and adverse effects were also measured. Participants who received the G. lucidum extract had improved IPSS compared with the placebo group. In addition, no severe adverse effects were reported. Larger, long-term studies are required to determine if G. lucidum extracts could further improve LUTS as well as urinary flow in men with more severe LUTS.