- Many compounds with medicinal effects, such as penicillin, were originally isolated from fungi.
- Fungi produce a vast number of bioactive compounds, many of which have not been investigated for their potential medicinal benefits.
- Many claims have been made about the potential medicinal benefits of mushrooms—a type of fungi—but there is little evidence to support claims made by the supplement industry, which is largely unregulated.
- A recent study found that nerve cells exposed to compounds isolated from lion’s mane mushrooms could promote neuron growth.
Many claims are made about mushrooms’ medicinal properties due to the fact that fungi are capable of creating a vast array of molecules, not all of which have been studied for their individual properties or medicinal potential.
However, there is a lack of evidence to support these claims, largely as the molecules which could have a medicinal effect have not been isolated or studied in the laboratory or in humans. Many of the claims made also allude to the consumption of mushrooms as a whole rather than the effects of individual molecules they might contain, as the dietary supplement industry is not regulated in the same way that medicines are.
The fungi species, Hericium erinaceus, more commonly known as lion’s mane mushroom, has been used in traditional Chinese medicine for years and is the focus of many claims made about its potential medicinal uses.
Claims have been made about the potential benefits of this particular fungi in treating neurodegenerative conditions, and there is an ongoing trial to determine the effects of taking the fungi in capsule form on Parkinson’s disease patients, for example.
In order to observe the effect of the fungi on neurons in the laboratory, researchers in South Korea and Australia isolated several compounds from lion’s mane fungi as well as tested a crude extract from the mushrooms.
Twice the neuron growth from mushrooms
“I am a molecular neurobiologist, and we do grow neurons in a dish on an ongoing basis for many projects. One of my former Ph.D. student[s] YeJin Chai alerted me that the lion’s mane mushroom could have an activity on neurons and we, therefore, got involved in a collaboration and tested several compounds extracted from this mushroom.”
“It became clear that some of these compounds had potent activity when we realized that the length and number of branches dramatically increased,” he said.
To study this hypothesis, researchers exposed neurons derived from rat embryos to lion’s mane mushroom extracts for 24 hours and compared the length of the neurons and their branching to neurons in a control group.
They found the neurons exposed to lion’s mane mushroom extracts were up to twice as long as those not exposed.
Further analysis of cells from the hippocampus region of the brain showed that neurons showed the most growth when exposed to four separate isolated molecules with hericene A and NDPIH having the greatest effect on neuron growth.
Researchers then gave mice supplements of lion’s mane mushroom and tested their memory in a maze test.
They found that dietary supplementation with lion’s mane mushroom crude extracts significantly enhanced mice’s recognition memory.
Should I take mushroom supplements?
medical toxicologist, co-medical director, and interim executive director at the National Capital Poison Center, who was not involved in the study, called the study an interesting piece of research that “will hopefully stimulate further research in this field.”
However, she also called for caution when interpreting the findings.
“For now, we don’t know whether the changes that were noted in the in vitro or mouse investigations are applicable to humans,” she stressed.
The safety profile of these molecules is also unclear for humans for now.
“Additionally, we don’t know if there are any side effects of this mushroom extract when used in humans. The study investigators did note that some chemicals that act on the brain extract can cause unwanted effects like pain, spasticity, and even brain damage, and we don’t know if lion’s mane mushroom extract will have similar adverse effects in humans,” Dr. Johnson-Arbor told MNT.
There is also the issue of supplement regulation.
“The dietary supplement industry is highly unregulated, and products marketed as dietary supplements are not FDA-approved to prevent, treat, or cure any disease. In addition, dietary supplements may contain unwanted contaminants or other ingredients that may be harmful when consumed by humans,” she said.
Trials in Alzheimer’s patients
Dr. Meunier said that understanding the underlying mechanisms behind these findings is a priority for the team. This means that they will have to determine which receptors in the cell the different molecules are binding with and how.
“A clinical trial is ongoing in Korea to test the efficacy of some of these molecules in a cohort of Alzheimer patients,” he said.
“I am particularly interested in understanding how these molecules act on our nervous system. Finding the receptor will allow a much deeper understanding of how such receptor is involved in memory formation and how to generate optimized compounds that specifically target this receptor,” he concluded.
FROM OUR EXPERT NUTRITIONISTS
What are the benefits of lion’s mane mushrooms?
Lion’s mane mushrooms (Hericium erinaceus) are white, globe-shaped fungi that have long, shaggy spines. People can eat them or take them in the form of supplements. Research suggests that they may offer a range of health benefits, including reduced inflammation and improved cognitive and heart health.
People in Asia use these mushrooms for both culinary and medicinal purposes. Health food stores sell lion’s mane extract in supplement form, and both the fungus and its extracts appear to be beneficial to health.
Here we discuss the potential benefits of lion’s mane mushrooms and consider the possible risks and side effects of their use.
Lion’s mane mushrooms may help with the following:
Inflammation and oxidation
Immune function
Lion’s mane mushrooms may enhance the immune system, partly by reducing inflammation and preventing oxidation.
ResearchTrusted Source on mice suggests that lion’s mane mushrooms may boost the activity of the intestinal immune system.
The results of another studyTrusted Source on mice indicate that a protein in lion’s mane mushrooms encourages the growth of beneficial gut bacteria that strengthen immunity.
Anxiety and depression
In a 2015 studyTrusted Source, mice that consumed lion’s mane mushroom extract displayed fewer depressive behaviors and had blood markers that indicated lower depression. The researchers suggest that this is due to the extract’s anti-inflammatory effects.
The findings of a 2018 animal studyTrusted Source support this, with the authors concluding that these mushroom extracts may contain agents that are useful for treating depressive disorders.
In a small Japanese study, women with a variety of health complaints, including menopausal symptoms and poor sleep quality, ate cookies containing lion’s mane extracts or placebo cookies for 4 weeks. The participants who ate the extract reported lower levels of irritation and anxiety than those in the placebo group.
Cognitive health
It is possible that lion’s mane mushrooms might boost cognitive function, but the existing research is mainly on animals.
In one studyTrusted Source, lion’s mane dietary supplements appeared to give mice better object recognition and recognition memory.
Other researchersTrusted Source have concluded that the mushrooms may have the potential to treat or prevent diseases that cause a decline in cognitive health, such as Parkinson’s disease and Alzheimer’s disease.
However, there is currently a lack of research on the effects of lion’s mane mushrooms in humans with Alzheimer’s disease.
An older Japanese studyTrusted Source on adults aged between 50 and 80 years with mild cognitive impairment found that daily consumption of mushroom extract for 16 weeks led to higher scores on cognitive function scales compared with a placebo group. These scores decreased again once the participants stopped taking the extract.
Heart health
Lion’s mane extract may improve heart health, but the research to date has primarily used animal subjects.
Cancer
The antioxidant properties of lion’s mane mushrooms may play a role in cancer prevention or treatment.
The results of an in vitro studyTrusted Source indicate that lion’s mane extracts have therapeutic potential against human leukemia.
A studyTrusted Source using animal models found that these mushroom extracts may also fight liver, colon, and gastric cancer cells.
These findings are promising, but it is not currently possible to confirm that the same effects will apply in people.
Diabetes
Controlling blood sugar levels is key to managing diabetes. In one studyTrusted Source, blood sugar levels in rats with diabetes were lower after they received lion’s mane mushroom extract for 4 weeks.
One of the complications of diabetes is nerve damage resulting from prolonged periods of high blood sugar. A 2015 studyTrusted Source on rats, in which they ingested lion’s mane extract for 6 weeks, showed positive results, including lower blood sugar levels, reduced feelings of nerve pain, and improved antioxidant activity.
Digestive health
Lion’s mane may help digestive health by fighting inflammation, which could be beneficial for people with inflammatory bowel disease (IBD). The mushroom may also boost immune function and encourage the growth of good bacteria in the gut.
In vitro studies reportTrusted Source that lion’s mane mushrooms can result in antibacterial activity that may improve digestion. ResearchTrusted Source in mice supports these findings by showing that extracts of lion’s mane may protect against stomach ulcers.
Wound healing
Extracts from lion’s mane mushrooms may provide healing benefits for skin wounds.
A studyTrusted Source on rats with neck wounds found that topical application of lion’s mane extract led to faster healing.
However, more extensive research is necessary for the medical community to recommend lion’s mane mushrooms for topical use on humans.
Nervous system recovery
Damage to the nervous system can have significant effects on health.
Some research suggestsTrusted Source that extracts of lion’s mane mushrooms may encourage nerve cells to grow and repair more quickly.
One studyTrusted Source showed that rats with nerve damage receiving a daily extract of lion’s mane mushrooms had quicker nerve regeneration than control animals.
Risks and side effects
Most studies on lion’s mane mushrooms have used animals, but it appears to be safe to eat the mushrooms in moderate quantities, as people do in many countries in Asia.
The safety and effectiveness of lion’s mane supplements are less apparent because dietary supplements do not have the same regulations as food and drug products.
However, in the animal studies, even high doses did not produceTrusted Source adverse effects in the rodents.
People wishing to incorporate lion’s mane mushrooms into their diet should cook them until the outer layer is crispy as the taste can be bitter otherwise.
Supplements are available in stores and online in the following forms:
- capsule
- liquid
- tablet
- powder
The dosages of these supplements vary, and people should follow the instructions on the label carefully. It is also advisable to discuss the use of any new supplement with a doctor.
People who experience adverse reactions to lion’s mane mushrooms should stop using them and seek immediate medical attention.