The reishi mushroom has an ancient history of use in China, for over 2000 years, and is indicated for longevity, cancer treatment, autoimmune diseases, anxiety, insomnia, and cardiovascular health, amongst other uses (Dudhgaonkar et al., 2009). It is accepted that it is the triterpenes in reishi which are responsible for its anti-inflammatory activity, while its polysaccharides stimulate the immune system. However, there is controversy surrounding whether the fruiting body (above ground part) or mycelium (root like structure) is better for medicinal purposes. Many companies are selling only mycelium grown on grain (rice), which is cheaper, but opposed to tradition. Traditionally, it was the fruiting body of reishi that was used as a medicine (Jong and Birmingham, 1992) and linked with longevity. So, the question is, how much does this matter?
Despite their different locations, both the mycelium and fruiting body contain similar medicinal compounds, such as the polysaccharides and triterpenes (Jong and Birmingham, 1992). However, there are more specific dissimilarities between these molecules between the two parts of the fungus. For example, gandoderic acids (triterpenes) A, B, and H have been detected only in the fruiting body, whereas, gandoderic acids R, S, and T were found in the mycelium. Notably, to extract the triterpenes efficiently alcohol is required. This is important, as traditionally just a hot water extraction has been used when TCM doctors ask for a decoction to be made. However, many of the polysaccharides are in fact hot water soluble (Sone et al., 1985) and so hot water can be used to extract them. Therefore, a dual hot water and alcohol extraction of reishi is preferred. Both polysaccharides from the fruiting body and mycelium have been shown to be active against tumours in vivo model studies (Sone et al., 1985).
Figure 1. (left) Mycelium from an oyster mushroom, these are often grown in either flasks or petri dishes for scientific studies. (right) A Reishi fruiting body, the part traditionally used as a medicine in humans.
Another point made in the review article is that a bitter taste has long been associated with the medicinal properties of reishi, and it is the triterpenes which taste bitter (Jong and Birmingham, 1992). Therefore, when testing different extracts of reishi, a bitter taste is a good sign. Reishi also should not be considered a single medicine and its properties change depending on the life cycle, extraction location, extraction method, and growing environment of the mushroom. The fruiting body has been most studied scientifically, however the mycelium also receives a great deal of attention in studies as well. The two currently highest impact papers on reishi, one published in PNAS describing anti-tumour activity (Liao et al., 2013) and another in Nature Communications describing a therapeutic effect on obesity (Chang et al., 2015), both in mice, used a fruiting body extract or a mycelium body extract, respectively. Various human studies have used the fruiting body extracts, but also spore extracts (Tang et al., 2005; Zhao et al., 2012). It is far from clear whether the mycelium, fruiting body, or spore extracts are preferred, it may emerge to be the case they are better for different applications.
Growth of mycelium for studies is often done in shaking flasks where substrates like glucose are added (Yang et al., 1998). They also may be grown in petri dishes in solid culture (Heleno et al., 2012). This contrasts with most companies who grow the reishi on a grain substrate. It is unclear what the consequences are of this process, as scientific studies comparing these types of growing condition have not been conducted and published. However, it is common knowledge amongst mushroom enthusiasts that excess grain has crept into some medicinal mushrooms products. Due to this process some extracts are weak due to lack of active constituents.Many companies are not stating what part of the fungus their reishi comes from. I believe this to be potentially misleading. Nor are they stating how exactly their reishi was extracted or grown. It is important to be transparent when providing extracts of medicinal mushrooms to the public. In the absence of widely accepted standards and knowledge, I currently prefer reishi that is grown in a way similar to how it grows in nature. This is on logs and organically, I also prefer a dual extract using water and alcohol of the fruiting body, not mycelium. This is in line with the traditional use of the mushroom, except a decoction avoids use of alcohol and therefore will be lacking in triterpenes compared with the more modern duel extract. It is possible to get a duel extracted tincture from herbalists or make your own which should be effective, although powdered capsules are also reasonable.
Chang, Chih-Jung, et al. “Ganoderma lucidum reduces obesity in mice by modulating the composition of the gut microbiota.” Nature communications 6 (2015): 7489.
Dudhgaonkar, Shailesh, Anita Thyagarajan, and Daniel Sliva. “Suppression of the inflammatory response by triterpenes isolated from the mushroom Ganoderma lucidum.” International immunopharmacology 9.11 (2009): 1272-1280.
Jong, S. C., and J. M. Birmingham. “Medicinal benefits of the mushroom Ganoderma.” Advances in applied microbiology. Vol. 37. Academic Press, 1992. 101-134.
Heleno, Sandrina A., et al. “Fruiting body, spores and in vitro produced mycelium of Ganoderma lucidum from Northeast Portugal: A comparative study of the antioxidant potential of phenolic and polysaccharidic extracts.” Food Research International 46.1 (2012): 135-140.
Liao, Shih-Fen, et al. “Immunization of fucose-containing polysaccharides from Reishi mushroom induces antibodies to tumor-associated Globo H-series epitopes.” Proceedings of the National Academy of Sciences 110.34 (2013): 13809-13814.
Sone, Yoshiaki, et al. “Structures and antitumor activities of the polysaccharides isolated from fruiting body and the growing culture of mycelium of Ganoderma lucidum.” Agricultural and biological chemistry 49.9 (1985): 2641-2653.
Tang, Wenbo, et al. “A randomized, double-blind and placebo-controlled study of a Ganoderma lucidum polysaccharide extract in neurasthenia.” Journal of medicinal food 8.1 (2005): 53-58.Yang, F-C., and C-B.
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Zhao, Hong, et al. “Spore powder of Ganoderma lucidum improves cancer-related fatigue in breast cancer patients undergoing endocrine therapy: a pilot clinical trial.” Evidence-Based Complementary and Alternative Medicine 2012 (2012).