Reishi has been recognized as one of the most powerful cancer fighting food worldwide. It has a long history of use in the treatment of cancer and is credited with many cases of spontaneous remission.
There are many published studies on its anti-cancer effects in various human and mouse tumor cell lines. Although the evidence from well-designed clinical trials is not available yet, there is considerable evidence to support the immune stimulating activities of Reishi through increased cytokine production and enhancement of immunological effector cells according to Herbal Medicine: Biomolecular and Clinical Aspects. 2nd edition.
Reishi polysaccharide beta-glucan has the most profound impact on the immune system. The level of anti-cancer activity is related to its degree of branching and to solubility in water, with higher solubility and greater degree of branching being associated with higher activity. Ganoderic acid, a Reishi triterpene, also has significant anti-cancer properties. When Reishi was used as a single agent on metastatic cancer patients, significant enhancement of cellular immunity was noted with high plasma concentrations of interleukin-2 and interferon-gamma, and natural killer (NK) cell activity according to the article “A Phase I/II Study of a Ganoderma lucidum (Curt.: Fr.) P. Karst. Extract (Ganopofy) in Patients with Advanced Cancer”.
Another study in advanced lung cancer showed improvement of total T cells and NK cells in 65% of patients taking Reishi extract.
Systemic Review of Reishi & Cancer drug interaction – posted on Feb/18/2021
Lam CS, Cheng LP, Zhou LM, Cheung YT, Zuo Z. Herb-drug interactions between the medicinal mushrooms Lingzhi and Yunzhi and cytotoxic anticancer drugs: a systematic review. Chin Med. 2020 Jul 25;15:75. doi: 10.1186/s13020-020-00356-4. PMID: 32724333; PMCID: PMC7382813.
Link to free full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7382813/
In this systematic review, Lam and colleagues discuss existing literature on the herb-drug interactions between Lingzhi and Yunzhi (medicinal mushrooms) and cytotoxic anticancer drugs. Here, we present a summary of their findings with specific regard to Lingzhi, or Reishi mushrooms–the star ingredient of MD Nutraceutical herbal teas.
On average, 35% of cancer patients across the United States, Canada, and Europe have used Chinese herbal medicine during their treatment. In Asian countries, the concurrent use of Chinese herbs with cancer therapy is thought to be even higher. Drawing from 213 studies (clinical, animal, and in-vitro) published in both Chinese and English databases, this systematic review concludes that interactions between Lingzhi mushrooms and various chemotherapy drugs lead to largely beneficial health outcomes for patients.
Three clinical studies on Lingzhi mushrooms specifically measured survival outcomes, with two reporting increase in survival rate. Clinical, animal, and in-vitro studies all observed an increase in disease control rate through reduction in tumor size with Lingzhi co-administration. Potential mechanisms include synergistic effects with cytotoxic drugs, inhibition of tumor cell angiogenesis, increased reactive oxygen species production, or reversal of tumor cell resistance to chemotherapy. In other studies, Lingzhi co-administration also relieved bone marrow suppression caused by chemotherapy, while some combinations even increased the number immune cells including T cells, CD4+/CD8+ ratio, and Natural Killer cells.
More clinical evidence exists supporting the role of Lingzhi co-administration in improving quality of life for cancer patients. Of 12 total studies observing greater quality of life, eight focus on lung cancer patients. In addition, co-administration of Lingzhi reduced common adverse effects of chemotherapy drugs, including nausea, vomiting, constipation, diarrhea, stomatitis, and nephrotoxicity.
Overall, no harmful Lingzhi-chemotherapy interactions were reported in this review, and Lingzhi co-administration appears to be safe and effective in reducing tumor size and improving quality of life for cancer patients. Limitations of this systematic review include modest methodological quality of clinical evidence, lack of blinding in studies, and a lack of pharmacokinetic information available on the herb-drug interactions discussed.
Reishi has been studied in multiple clinical conditions including:
Fighting fatigue and depression: A 2005 controlled study by New Zealand Institute of Natural Medicine Research found that fatigue in neurasthenia patients was significantly improved after 8 weeks of taking Reishi supplements. Another study found that Reishi reduced fatigue while improving quality of life for participants after only 4 weeks.
Promoting a healthy heart: A study by the Department of Medicine and Therapeutics at the Prince of Wales Hospital in Hong Kong found that Reishi increased HDL cholesterol while decreasing triglycerides in the blood according to Study of potential cardioprotective effects of Ganoderma lucidum (Lingzhi): results of a controlled human intervention trial.
Studies have also been published specifically assessing Reishi supplementation and cancer risk: An epidemiological study of 2000 Chinese women, half of them with breast cancer and half without, found reduced risk of breast cancer in women who regularly consumed mushrooms (10g/day fresh or 4g/day dried) and drank green tea (1.05g/day dried green tea leaves). There was an increased reduction in women who did both. Int J Cancer 2009; 124(6):1404-8)
Two Korean studies of women with histologically confirmed breast cancer, one with 362 women and the other with 358, also found a strong inverse correlation between mushroom consumption and breast cancer risk, with the strongest association in women with ER+/PR+ tumors. Int J Cancer 2008; 122(4):919-23; J. Nutr Cancer 2010; 62(4):476-83
In studies of the population in the Nagano area of Japan, mushroom farmers had a much lower rate of death from cancer than the general population