The lack of standardization of mushroom-containing products and lack of comparative clinical research remain significant obstacles to more widespread use. Unfortunately, the goal of most medicinal mushroom research has been to increase sales opportunities rather than provide the information that clinicians need. In the vast majority of cases, there are no reported interactions between Reishi and prescription medications. Mushroom extracts are routinely prescribed alongside prescription drugs, especially chemotherapeutic agents, in China and Japan.
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