Medicinal Mushrooms for Immunity

Immune system function is essential, but now more than ever we're looking at our immunity especially in light of the pandemic. We want to have our immune system ready to go should we come in contact with pathogens or viruses. Medicinal mushrooms are highly regarded in traditional medicine and play a big role in immune function; while they are by no means a cure-all, they are a great complement to healthy diet and lifestyle to keep your immune system in peak form.

Although there are many different medicinal mushrooms, five commonly appear in blends and are used more widely, and those are:

• Lion's Mane
• Turkey Tail
• Reishi
• Chaga
• Cordyceps

While they all have their own distinct benefits, they all help regulate human immune function with studies showing their enhancing both adaptive and innate immunities, meaning that they not only help nurture our current immune function but actively work with our immune cells to create balance. Additionally, these mushrooms have adaptogenic properties meaning they help our bodies process and adapt to stress. Stress is proven to be a major contributing factor in a lot of chronic disease and impaired immune function. 

Two examples that show the natural potency of medicinal mushrooms and how closely tied our immune function is to our intestinal function are reishi (ganoderma lucidum) and turkey tail (coriolus versicolour).

Research shows that reishi prevents bacterial and viral infections by activating our bodies' immune system. Our immune system is constantly functioning by surveilling the contents of our blood and cells, so reishi supports this function to identify and eliminate harmful pathogens. In particular, it activates proteins involved in cell death to destroy abnormal or affected cells to identify and discourage further abnormal cell growth.

Turkey tail is helpful in balancing our gut bacteria. Turkey tail contains immune supporting compounds called polysaccharopeptides, Krestin (PSK) and Polysaccharidpeptide (PSP). These compounds increase white blood cells and stimulate dendritic cells (messengers between our adaptive and innate immune systems), which allow our bodies to naturally strengthen our immune system and fight infections effectively. The PSP in turkey tail functions as a prebiotic, meaning that it helps regulate our beneficial gut bacteria. Prebiotics are also a type of fiber which our good gut bacteria can feed on to support their function and produce metabolites that further contribute to good gut health!

A particularly potent compound in mushrooms, beta glucans, are carbohydrates (or polysaccharides) found in fungi cell walls. They are acid resistant so they are able to pass through our stomach in-tact and enter the small intestine, where they act on intestinal immune cell receptors. This leads to various immune responses, prompting white blood cells to function in both the adaptive and innate immune system. It triggers effective immune responses including phagocytosis (how our defence cells engulf 'invaders') and stimulating the production of cytokines, which leads to the elimination of infectious matter.

That being said, they also work antagonistically on inflammation that comes with stimulating the immune system, meaning that they function to balance the immune system so it does not over or under function, keeping us in optimal health! This bi-directional modulation of our immune system is unique to medicinal mushrooms, making them a powerhouse in supporting our immunity - they help our natural defence cells function optimally and encourage an immune response, while ensuring that our immune response is appropriate in both intensity and duration to prevent chronic inflammation in our bodies!

Some of the ways that the polysaccharides in mushrooms support the immune system are (1):

• Activation of immune cells
• Increased antibody production
• Increased interferon production
• Increased immune activity against a range of cancers
• Inhibition of tumour metastasis
• Reduction in pro-inflammatory cytokines
• Inhibition of prostaglandin synthesis

We've previously looked at the roles that nutrition and lifestyle play in our mental health. Through similar mechanisms and pathways, our gut health impacts our immune health. The intestinal receptor and beta-glucan interaction mentioned earlier influence our gut bacteria composition which is very closely tied to immune function. Bacteria and bacterial metabolites (created by gut bacteria based on the foods we eat - another reason that nutrition is so important!) can either suppress or support immunity. 

These beta-glucans have prebiotic properties which support the growth of beneficial gut bacteria and allow for more efficient and effective communication to immune cells. They also function to increase the integrity of intestinal mucosa cells to prevent chronic inflammation and leaky gut which are caused by an overgrowth of 'bad' gut bacteria that shift our immune system into an increased inflammatory state.

The medicinal mushrooms listed above are supplemental and we recommend consulting a health professional before adding them into your routine! They generally come in tincture or powder form and can be easily added to smoothies, blended coffees, or nut butter as the fat of the almonds allows a slower release of the beneficial compounds! Beta-glucans are also found in shiitake and oyster mushrooms, so eat up!

Sources:

Chi-Fung Chan G, Chan WK, Man-Yuen Sze D. The effects of β-glucan on human immune and cancer cells. J Hematol Oncol 2009;2:25.

Guggenheim AG, Wright KM, Zwicky HL. Immune modulation from five major mushrooms: application of integrative oncology. Integrative Med 2014;13(1):32-44.

(1) Powell M. Medicinal mushrooms: The essential guide. Mycology Press, 2013.

Rop O, Vlcek J, Jurikova T. Beta-glucans in higher fungi and their health effects. Nut Rev 2009;67(11):624-631.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3339609/