Lion’s mane is an edible mushroom which is currently being investigated for its potential cognitive benefits. Plus, animal studies have uncovered several other future avenues for human trials. What have researchers found? Read on to learn more.
What is Lion’s Mane Mushroom?
Lion’s mane is an edible mushroom with medicinal properties. This fungus is known by many other names, including hedgehog mushroom, monkey’s mushroom, bear’s head, old man’s beard, yamabushitake (Japanese), houtou (Chinese) and Hericium erinaceus (its Latin scientific name) [1, 2].
It has been used in traditional Chinese and Japanese medicine throughout history. It is also commonly consumed in many other Asian countries such as Korea and India [3, 1, 4].
Apart from vitamins and minerals, Lion’s Mane also contains some specific compounds such as hericerins, erinacines, erinaceolactones, and specific glycoproteins and polysaccharides [5].
Components and extracts of Lion’s Mane have proven antibiotic, anticancer, neuroprotective, fat- and glucose-lowering effects. This mushroom also protects against stomach ulcers, improves anxiety, cognitive function, and depression, and has anti-fatigue and anti-aging properties [6, 2].
All of these beneficial effects are based on three important properties of this mushroom: it decreases inflammation, acts as an antioxidant, and stimulates the immune system [6].
Mechanisms in Cell Studies
Lion’s Mane can both increase and decrease pro-inflammatory cytokines depending on the context.
In cell studies, under different conditions, lion’s mane:
- Increased [2] and decreased TNF [7, 8, 9, 10, 11, 12].
- Increased [13] and decreased IL-1beta [11, 12].
- Increased [13, 14] and decreased NF-κB [7, 15, 16].
- Increased [14] and decreased NO [9, 15, 16, 12].
- Increased IL-12 [17], IFN-γ [2] and activated NK cells [2].
- Decreased IL-6 [8, 11, 12] and IL-8 [2].
- Increased IL-10 [10].
- Increased iNOS [14], LXA4 [18], PPAR alpha [19], HSP70 [20], CAT, GSH-Px, and GSH [21].
- Increased [13] and decreased AP-1 [15].
- Increased [21] and decreased SOD [11].
- Increased nerve growth factor (NGF) [2].
- Decreased VEGF, COX-2, 5-LOX [22], BAX [20], TLR4, JNK [8, 16], MDA [11, 21], PGE2 [15, 16], p38 MAPK and CHOP [12].
- Decreased MMP-9 and ICAM-1 [7].
Health Benefits of Lion’s Mane
The following purported benefits are only supported by limited, low-quality clinical studies. There is insufficient evidence to support the use of lion’s mane for any of the below listed uses. Lion’s mane has not been approved by the FDA for any medical purpose or health claim.
Insufficient Evidence For
The following purported benefits are only supported by limited, low-quality clinical studies. There is insufficient evidence to support the use of lion’s mane for any of the below-listed uses. Remember to speak with a doctor before taking lion’s mane, and never use it in place of something your doctor recommends or prescribes.
1) Brain Function
In 50- to 80-year-old Japanese men and women diagnosed with mild cognitive impairment, lion’s mane improved cognitive function. However, cognitive function decreased again after the termination of the treatment, and therefore continuous intake may be necessary [23].
In a study of mice with neurodegenerative diseases, lion’s mane improved both memory and cognitive function [4, 24].
Alzheimer’s Disease Research
Lion’s mane has anti-dementia activity in a mouse model of Alzheimer’s disease and in people with mild cognitive impairment [25, 26].
Levels of acetylcholine (ACh), a chemical that helps nerve cells communicate, normally decrease with age. However, in diseases such as Alzheimer’s, levels of acetylcholine can drop by as much as 90 percent. Many of the drugs that are currently used to treat this disease work to increase acetylcholine levels.
In a mouse model of Alzheimer’s, lion’s mane improved cognitive function and the brain cholinergic system function. It enhanced both acetylcholine and choline acetyltransferase (ChAT, an enzyme that produces acetylcholine) concentrations in the blood and in the hypothalamus [24].
In mice with Alzheimer’s, lion’s mane prevents the loss of spatial short-term and visual recognition memory [4].
In a similar setting, lion’s mane decreased the amyloid beta plaque burden in the brain. The plaque contributes to brain degradation in patients with Alzheimer’s [25].
It was shown that lion’s mane components protect neurons from amyloid beta-induced neurotoxicity [27].
Parkinson’s Disease Research
In a mouse model of Parkinson’s disease, treatment with lion’s mane reduced dopaminergic cell loss and attenuated motor deficits, suggesting that lion’s mane can slow down the progression of Parkinson’s Disease [28].
Lion’s mane has not yet been studied in the specific context of Alzheimer’s or Parkinson’s disease in humans, and clinical evidence in the context of brain function is very limited. Talk to your doctor before using lion’s mane, and never use lion’s mane in place of a prescribed medication.
2) Mood
In a four-week study, menopausal symptoms such as loss of concentration, irritability, palpitations, and anxiety significantly decreased when treated with Lion’s Mane extract. This alleviation of symptoms also improved sleep quality [29].
Amycenone, a lion’s mane component had antidepressant effects in mice [10].
Animal Research (Lacking Evidence)
No clinical evidence supports the use of lion’s mane for any of the conditions listed in this section. Below is a summary of the existing animal and cell-based research, which should guide further investigational efforts. However, the studies listed below should not be interpreted as supportive of any health benefit.
3) Nerve Regeneration
Lion’s mane enhanced nerve growth and regeneration in animal models, both in the brain and throughout the rest of the body [30, 2, 31, 30].
Lion’s mane also promoted nerve regeneration after limb injury in rats [32].
In a cell study, lion’s mane promoted nerve growth factor (NGF) production [2].
These effects have yet to be investigated in humans.
4) Immune System
Compounds found in lion’s mane improved immune function in mice. A polysaccharide from the mushroom enhanced both cell-mediated and humoral immunity; the authors suggested that the polysaccharide could regulate immune cell activity in the intestinal wall [33].
Lion’s mane polysaccharides also increased T cells and macrophage levels and appeared to promote antitumor activity of the immune system in mice [34].
In a cell study, lion’s mane also induced the maturation of human dendritic cells (antigen-presenting immune cells). Maturation of dendritic cells is an important process in the initiation and regulation of immune responses [35].
Bacterial Infection
Lion’s Mane may support the anti-bacterial immune response. In mice infected with a lethal dose of Salmonella typhimurium, Lion’s Mane extended lifespan and protected against liver damage [36].
Researchers have yet to conduct clinical trials investigating the effect of lion’s mane on the human immune system.
5) Scarring
In rats, wounds treated with lion’s mane extract scarred less and contained more collagen, but this result has yet to be repeated in other studies [37].
6) Inflammation
In mice with acute gut inflammation, lion’s mane improved symptoms and decreased intestinal bleeding [11].
In rats with brain injury, lion’s mane extracts reduced the size of the injury and decreased levels of inflammatory cytokines [12].
In a cell study, lion’s mane reduced excessive nitric oxide, prostaglandin, reactive oxygen species, and pro-inflammatory factors such as NF-κB [16].
Inflammatory markers have not yet been studied in people eating lion’s mane or taking lion’s mane supplements.
7) Cardiovascular and Metabolic Health
In rats fed a high-fat diet, lion’s mane reduced total cholesterol, LDL cholesterol, triglycerides and phospholipids and increased HDL cholesterol [38, 39].
Similarly, in mice on a high-fat diet, lion’s mane decreased body weight gain, fat weight, and blood and liver triglyceride levels [19].
In ovariectomized mice (a menopause model), lion’s mane decreased fat tissue, total cholesterol, and leptin [40].
The observed decreased in cholesterol in animals fed lion’s mane may be related to increased bacterial short-chain fatty acid production in the large intestine. Other possible factors include an accelerated rate of degradation of cholesterol to bile acids or a reduced ability to absorb fat [2, 40].
In a cell study, lion’s mane also exerted anti-inflammatory effects on macrophages and improved markers of fat tissue inflammation associated with obesity [8].
Lion’s mane has not been investigated as a potential cholesterol-lowering agent in humans.
8) Blood Glucose & Diabetes
Lion’s mane reduced blood glucose levels in both normal and diabetic mice by nearly 50% [2].
Lion’s mane also increased glucose tolerance in diabetic mice [2].
In diabetic rats, lion’s mane decreased blood glucose and increased insulin [21].
Diabetic Neuropathy Pain
In rats with diabetic neuropathy pain, lion’s mane significantly increased pain threshold while also improving glucose levels [41].
Researchers have not yet investigated whether lion’s mane can affect blood sugar or neuropathy pain in people with diabetes.
9) Circulation
Alcohol extracts of lion’s mane inhibit the production of excess blood vessel cells in rats. Excess blood vessel cells contribute to atherosclerosis [42].
In a cell study, a lion’s mane compound called hericenone B inhibited human and rabbit platelet aggregation, suggesting a possible role for lion’s mane in preventing clots. For the time being, lion’s mane should not be used in an attempt to stop blood clotting; however, we recommend caution with lion’s mane if you are taking any medication that thins the blood [43].
12) Gut Health
Lion’s mane extracts protected against alcohol-induced stomach lining injury and ulcers in rats [44, 20].
Lion’s mane also protected against gastritis [45] and colitis, possibly by suppressing inflammatory cytokines and reducing intestinal bleeding [11].
H. pylori Growth
Lion’s mane inhibited the growth of H. pylori in several cell studies. This activity has not been investigated in an animal model, let alone in humans [46, 47, 48].
13) Liver Function
A component of lion’s mane protected mice from chemically induced liver damage [49].
Lion’s mane decreased liver damage caused by acute alcohol exposure in mice, decreasing blood ALT, AST, and MDA levels [50].
14) Fatigue
In mice, lion’s mane extended the exhaustive swimming time, increased tissue glycogen content and antioxidant enzyme activity, and decreased biochemical parameters related to fatigue, including blood lactic acid, urea nitrogen, and malondialdehyde [51].
15) Healthy Aging
Lipofuscin is a waste product of human and animal aging metabolism. It is constantly accumulating in as cells age, contributing to cell atrophy (wasting). In both mice and flies, lion’s mane polysaccharides significantly reduced lipofuscin content [2].
On the other hand, superoxide dismutase (an enzyme that converts reactive oxygen species O- into oxygen or O2) decreases significantly with age. Lion’s mane polysaccharides increased the activity of superoxide dismutase in the brain and the liver of animals [2].
Lion’s mane also reduced markers of aging in human cell cultures [52].
Skin Aging
Lion’s mane has anti-aging effects on the skin. Polysaccharides found in this mushroom enhance antioxidant enzyme activities and increase collagen levels in aged rat skin [53].
16) Bone Density
Lion’s mane polysaccharides improved bone density and bone strength in rats [2].
Moreover, lion’s mane compounds inhibited the production of osteoclasts, cells that break down bone tissue, in the laboratory [54].
17) Circadian Rhythm
Lion’s mane extracts decreased wakefulness at the end of the active phase in mice. Furthermore, some components of lion’s mane can advance the sleep-wake cycle [55].
Therefore, researchers may investigate lion’s mane’s potential against conditions with circadian clock impairments, such as dementia, Alzheimer’s disease, and delayed sleep phase disorder [55].
18) Antiviral Activity
A lectin found in lion’s mane inhibits HIV-1 reverse transcriptase activity, which is important for the HIV virus to reproduce itself [56].
19) Antioxidant Activity
Lion’s mane possesses antioxidant properties; a boiled decoction of the mushroom had antioxidant activity in a dish which was about 17% as strong as quercetin [57].
The potential applications of this antioxidant activity are currently unclear.
Cancer Research
As early as 1992, studies reported that components of lion’s mane showed antitumor activity in animal studies. These components prolonged longevity and reduced the mortality of animal hosts [2].
Lion’s mane promotes the Th1 response, which is important for fighting tumors [2].
Lion’s mane polysaccharides also activate macrophages, which participate in the defense against tumor cells [2].
Lion’s mane inhibits blood flow to cancer cells and migration of tumor cells to other organs (metastasis). In mice, lion’s mane extracts induced cancer cell death and inhibited metastasis to the lungs [58, 59].
Researchers are currently investigating the effect of lion’s mane on several specific types of cancer cells, including [60, 61, 2, 62]:
- Leukemia (blood cancer)
- Liver cancer
- Colon cancer
- Stomach cancer
- Breast cancer
Side Effects & Safety
Lion’s mane is an edible mushroom, which is considered relatively safe when cooked and consumed in small amounts. There is currently no safety data concerning the use of lion’s mane extracts.
However, in humans, a single case of allergic contact dermatitis, and one case of acute respiratory failure associated with this mushroom were registered [63, 64].
There is also no safe and effective dose of lion’s mane because no sufficiently powered clinical trial has been conducted to find one. Talk to your doctor before using lion’s mane supplements.
Takeaway
Lion’s mane is an edible mushroom which has been a part of traditional medicine for many centuries. Modern research has found a potential use for lion’s mane in brain function and mood, while animal research suggests that it may modulate immunity and metabolism. Most of the available studies have been limited to animals and cells.
Lion’s mane is considered safe to eat as food, but safety data for lion’s mane at supplemental doses is incomplete.