Medicinal mushrooms: An introduction

Key to their ability to assist with many of these areas is the immune-modulating activity of the beta-glucans, proteoglycans and related polysaccharides which are important structural components of the mushroom cell wall.

Receptors with specific binding sites for such polysaccharides are found on many of the cells that make up the immune system and they have also been shown to have a prebiotic effect on the gut flora, promoting the growth of beneficial bacteria, enhancing intestinal barrier integrity, increasing levels of short-chain fatty acids and enzyme activity.

Given their positive immunological and prebiotic activity it is perhaps not surprising that increased mushroom consumption has been correlated with reduction in the risk of developing cancer in a number of large-scale epidemiological studies including three looking specifically at breast cancer risk and one at prostate cancer with regular mushroom consumption linked to a lower cancer risk in all cases, especially in older age groups.

As if that was not enough reason to reconsider mushrooms as an important food category for health maintenance, especially as we get older, mushrooms also produce an array of secondary metabolites with diverse health benefits.

Of these one of the most common is lovastatin, which like most other such secondary metabolites is produced by mushrooms and other fungi for its anti-microbial properties, in this case its anti-fungal action.

Other such compounds include:

• Triterpenes from several species including Reishi with actions including anti-inflammatory, sedative, anti-allergic, anti-hypertensive
• Diterpenes including erinacines and hericenones from Hericium species with NGF-promoting properties
• Nuceoside-derivatives such as Cordycepin with anti-viral, anti-inflammatory properties in Cordyceps species
• Ergothioneine, an antioxidant amino acid found in porcini and oyster mushrooms with anti-ageing properties
• Cordycepin and Long-Covid: Cordycepin (3’-deoxyadenosine) one of the key active molecules found in Cordyceps species, especially Cordyceps militaris is a close relative of Didanosine (2’,3’-dideoxyadenosine – used as part of HAART treatment for HIV/AIDS under the brand name Videx) and like Didanosine exhibits strong anti-viral activity. In addition it is a potent anti-inflammatory and contributes to Cordyceps’ traditional therapeutic use to increase energy and support the Lungs and Kidneys, including promoting steroid hormone production. With recent studies also pointing to protective properties for both cordycepin and Cordyceps militaris against lung injury from acute inflammation it is rapidly emerging as a promising candidate to help address the symptoms associated with Long Covid.

Mushrooms are also the only non-animal food to contain significant quantities of vitamin D with ergosterol in the cell wall converted to vitamin D2 on UV-exposure.