Medicinal mushrooms are well-established as natural alternatives to treat several conditions. Recently, the potential of these mushrooms in the treatment of Alzheimer’s disease (AD) has been the subject of many studies.
In this article, we look at the medicinal mushrooms that are known to be beneficial for patients with AD. Below is a list of mushrooms we cover within the article:
- Lion’s mane mushroom
- Chaga mushroom
- Cordyceps mushroom
- Reishi mushroom
- Turkey tail mushroom
- Maitake mushroom
Lion’s mane mushroom
Hericium erinaceus, commonly called lion’s mane mushroom, is well-known for its ability to promote nerve health and brain-related functions by stimulating neuronal growth factors.
Several studies have found that Alzheimer’s disease occurs in a chain-like reaction. When amyloid-β plaques are present, any secondary injury can trigger the progression of the chain reaction.
Lion’s mane can help regress this chain reaction via multiple mechanisms such as by:
- Decreasing the burden of amyloid-β plaques.
- Preventing recruitment and activation of neuronal cells associated with plaque formation.
- Enhancing the levels of nerve growth factor (NGF) synthesis.
- Increasing the proliferation of nerve cell progenitors in the central nervous system.
- Delaying neuronal cell death.
- Promoting recovery of neuronal function. 
Studies on Lion’s mane: Alzheimer’s disease
Several animal studies, two clinical trials, and many preclinical studies have demonstrated the benefits of taking lion’s mane for Alzheimer’s disease.
Human studies on Lion’s mane show that it may improve cognitive function in people with mild impairments in cognition. Results from another study found that taking 3 grams of Lion’s mane every day for 16 weeks improved cognition during the treatment period. [2, 3]
Improvement seen in cognitive function in these studies may be attributable to a reduction in inflammation, increase in nerve growth factors, and prevention of plaque formation. Further large-scale clinical trials are needed to evaluate the long-term effects of lion’s mane in patients with Alzheimer’s disease.
Inonotus obliquus, commonly called Chaga, is a fungus that has recently been garnering interest for its role in managing neurodegenerative diseases such as Alzheimer’s disease.
The mechanism by which Chaga mushroom can help people with Alzheimer’s disease is not understood completely. But, researchers believe that Inonotus obliquus polysaccharide (IOPS) derived from Chaga possesses neuroprotective properties. This is because of its ability to:
- Modulate oxidative stress, and inhibit mitochondrial apoptosis of neuronal cells.
- Reduce the release of lactate dehydrogenase, which is usually elevated in AD patients.
- Suppress excess accumulation of intracellular reactive oxygen species. 
Studies on Chaga mushroom: Alzheimer’s disease
There are limited studies that have evaluated the potential of Chaga mushrooms in treating patients with Alzheimer’s disease.
In an animal study in amyloid precursor protein/presenilin 1 (APP/PS1) transgenic mice, administering an 8-week course of IOPS showed improvement in both memory and cognition. 
The study concluded that IOPS, derived from Chaga mushrooms showed protective effects against Alzheimer’s disease owing to its anti-oxidant property.
Further studies are essential to determine the extent to which Chaga mushrooms can help treat Alzheimer’s disease.
Cordyceps militaris (CM) has anti-oxidant, anti-inflammatory, and neuroprotective properties. But, its role in managing cognitive disorders has not been extensively studied.
In theory, taking Cordyceps can be beneficial for patients with AD, because:
- It has been shown to inhibit the production of nitric oxide and lipid peroxidation in the kidney, liver, and brain.
- Cordycepin, derived from CM, has shown the ability to prevent neuronal degeneration
- CM can stimulate neurogenesis in the dentate gyrus, a major site of amyloid plaque deposition in AD.
- Cordyceps can inhibit lipid peroxidation and the formation of Nitric Oxide.
Studies on Cordyceps: Alzheimer’s disease
Animal studies that administered CM extract for 2 weeks found improvement in learning and memory function in mice models with AD. 
In a placebo-controlled clinical trial, mice models administered with CM extract were able to recognize new objects and navigate through new routes better than the placebo group.
The study concluded that daily doses of 100 to 200 mg per kg of CM prevented oxidative damage in AD mice models. CM may be useful in both preventing and treating AD progression. However, more studies are essential to understand how CM may help treat AD.
G. lucidum, also known as Reishi mushroom, is famous for its anti-aging benefits. But, its benefit in improving memory and cognition is not widely known. Recent studies on Reishi have found that it possesses the ability to delay the progression of AD.
The potential of Reishi mushrooms in helping patients with Alzheimer’s disease can be credited to the many mechanisms by which it acts as an anti-aging agent such as:
- Promotion of neural progenitor cell (NPC) proliferation to enhance neurogenesis and alleviate cognitive deficits in transgenic AD mice.
- G. lucidum polysaccharides (GLP) promote self-renewal of NPC.
- Protection of dopaminergic neurons by inhibiting lipopolysaccharide-induced inflammation.
Studies on Reishi: Alzheimer’s disease
In a study on Reishi mushrooms, GLP showed positive effects in AD mice models with mild cognitive impairment by alleviating cognitive defects and promoting neurogenesis.
However, the exact mechanism by which GLP works for AD is still not clearly understood. The animal study concluded that GLP may work as a therapeutic and preventive agent in neurodegenerative diseases such as Alzheimer’s disease. 
Turkey tail mushrooms
Trametes versicolor, also known as turkey tail mushroom has antioxidant properties, which may be responsible for the neuroprotective effects of the mushroom.
The potential of the turkey tail mushroom to benefit patients with Alzheimer’s disease may be due to its:
- Antiradical properties.
- Acetylcholinesterase (AChE) inhibitory activities. 
In Alzheimer’s disease, there is a deficiency of the neurotransmitter, acetylcholine. Acetylcholine is broken down by acetylcholinesterase, and by inhibiting its action, the concentration of acetylcholine can be increased.
Studies on Turkey tail: Alzheimer’s disease
A study on mice models found that when the turkey tail mushroom was administered at a concentration of 100 μg/mL, significant AChE inhibitory activity was observed. Two flavonoid compounds, namely baicalein and quercetin were believed to be responsible for the AChE inhibitory activity.
The study concluded that turkey tail extract could be used as a natural source of AChE inhibitors and antioxidants, thereby benefiting patients with Alzheimer’s disease. 
Grifola frondosa, commonly known as Maitake, is a medicinal mushroom with a great amount of beneficial bioactive compounds.
Maitake mushrooms may improve impairments in memory, learning, and cognitive function. This may be attributable to its following actions:
- Proteo-β-glucan, a polysaccharide found in Maitake, is known to possess neuroprotective and immunomodulatory activities.
- Activation of microglia and astrocytes, promoting the breakdown of Aβ plaques by recruiting microglia.
- Enhancing phagocytosis of amyloid plaques.
Studies on Maitake: Alzheimer’s disease
In a study conducted on AD mice models, Maitake mushrooms improved impairments of memory and learning by limiting neuronal loss and pathological tissue abnormalities.
The study concluded that the administration of Maitake mushrooms can improve AD symptoms such as memory impairment due to its immunomodulatory action. Supplementing with Maitake mushrooms may be beneficial to prevent aging-related dysfunction in memory and cognition. 
Conclusion: Can medicinal mushrooms help treat Alzheimer’s disease?
Medicinal mushrooms have been in use for many centuries, but only recently has the scientific community shown interest in their potential as neuroprotective agents in Alzheimer’s disease (AD).
With an increasing number of clinical trials and studies demonstrating the potential of medicinal mushrooms in the treatment of neurodegenerative disorders such as AD, medicinal mushrooms such as lion’s mane mushroom may be routinely used in all dementia patients in the near future.
- Li, I., et al. “Neurohealth properties of Hericium erinaceus mycelia enriched with erinacines.” Behavioural neurology 2018 (2018). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5987239/
- MLAMori, Koichiro, et al. “Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: A double‐blind placebo‐controlled clinical trial.” Phytotherapy Research: An International Journal Devoted to Pharmacological and Toxicological Evaluation of Natural Product Derivatives 23.3 (2009): 367-372. https://onlinelibrary.wiley.com/doi/abs/10.1002/ptr.2634
- Saitsu, Yuusuke, et al. “Improvement of cognitive functions by oral intake of Hericium erinaceus.” Biomedical Research 40.4 (2019): 125-131. https://www.jstage.jst.go.jp/article/biomedres/40/4/40_125/_article/-char/ja/
- Han, Yanqiu et al. “Inonotus obliquus polysaccharides protect against Alzheimer’s disease by regulating Nrf2 signaling and exerting antioxidative and antiapoptotic effects.” International journal of biological macromolecules vol. 131 (2019): 769-778. doi:10.1016/j.ijbiomac.2019.03.033. https://pubmed.ncbi.nlm.nih.gov/30878614/
- He, Mei Tong et al. “Protective role of Cordyceps militaris in Aβ1-42-induced Alzheimer’s disease in vivo.” Food science and biotechnology vol. 28,3 865-872. 4 Dec. 2018, doi:10.1007/s10068-018-0521-z. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6484065/
- Huang, Shichao et al. “Polysaccharides from Ganoderma lucidum Promote Cognitive Function and Neural Progenitor Proliferation in Mouse Model of Alzheimer’s Disease.” Stem cell reports vol. 8,1 (2017): 84-94. doi:10.1016/j.stemcr.2016.12.007. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5233449/
- Janjušević, Ljiljana et al. “The lignicolous fungus Trametes versicolor (L.) Lloyd (1920): a promising natural source of antiradical and AChE inhibitory agents.” Journal of enzyme inhibition and medicinal chemistry vol. 32,1 (2017): 355-362. doi:10.1080/14756366.2016.1252759. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6010034/
- Bai, Yao, et al. “A Maitake (Grifola frondosa) polysaccharide ameliorates Alzheimer’s disease-like pathology and cognitive impairments by enhancing microglial amyloid-β clearance.” RSC Advances 9.64 (2019): 37127-37135. https://pubs.rsc.org/en/content/articlehtml/2019/ra/c9ra08245j
Medicinal Mushroom Supplements in North america
For our recommendations of the best quality medicinal mushroom supplements in the United States and Canada, please read our guides:
- Best Chaga supplements
- Best Cordyceps supplements
- Best Lion’s Mane supplements
- Best Reishi supplements
- Best Turkey Tail supplements
Medicinal Mushroom Supplements in Australia
If you are looking for medicinal mushrooms in Australia, check out the following articles: