A Neuroprotective Powerhouse
Hericium erinaceus, commonly known as lion’s mane, bearded tooth fungus, monkey’s head, yamabushiitake (in Japan), or hou tou gu (in China), has been used for centuries in traditional Chinese medicine, but its popularity has recently surged in the West due to its remarkable health benefits. These coral-like mushrooms are not only an exciting medicinal species but also a delicious edible mushroom, and can be found in specialty grocery stores, or even at your local farmer’s market. There is now extensive research that shows that lion’s mane holds promise in the treatment and prevention of neurodegenerative diseases such as Alzheimer's, dementia, Parkinson's, and other related conditions. In this blog post we’ll take a deep dive into the mechanisms through which lion’s mane exerts its neuroprotective effects, with a particular focus on its ability to stimulate nerve growth factor (NGF) synthesis through its rich content of bioactive compounds like erinacines and hericenones.
Understanding Neurodegenerative Diseases
Neurodegenerative diseases occur when nerve cells (also known as neurons) in the brain or peripheral nervous system lose function over time and ultimately die. Although certain treatments may help relieve some of the physical or psychological symptoms, no cures exist. This is why it’s even more important to protect the neurons in the brain, in order to prevent or slow down the natural process of neurodegeneration as we age. Conditions like Alzheimer's and Parkinson's are the most common and lead to cognitive decline, memory loss, and impaired motor functions. The likelihood of developing a neurodegenerative disease rises dramatically with age, and as life expectancy increases, we will start to see more people affected by these diseases. The exact causes are multifaceted and involve genetic, environmental, and lifestyle factors. However, one common thread is the role of oxidative stress and inflammation in accelerating nerve cell damage and death.
The Role of Nerve Growth Factor (NGF)
As I said earlier, lion’s mane mushrooms stimulate the synthesis of NGF in our bodies. NGF is a crucial protein involved in the growth, maintenance, and survival of neurons. It supports neurogenesis (the formation of new neurons) and synaptogenesis (the formation of synapses between neurons), both of which are critical for learning, memory, and overall cognitive function. As we age, the production of NGF naturally declines, making our brains more susceptible to neurodegenerative diseases. Exogenous nerve growth factors created in a lab are unable to cross the blood-brain barrier and are easily metabolized by peptidases in the body. Consequently, their use as drugs in the treatment of neurodegenerative diseases may be challenging. For this reason, research is being conducted on compounds that can cross the blood-brain barrier and promote NGF synthesis in situ. For further reading you can look at this review by Bing-Ji Ma et al. (1)
Erinacines and Hericenones: The Bioactive Compounds
Lion's mane mushrooms owe much of their neuroprotective power to two groups of compounds: erinacines and hericenones. These compounds are unique to lion’s mane and research has shown that they’re directly responsible for many of its medicinal properties.
Erinacines are a group of bioactive compounds capable of crossing the blood-brain barrier and inducing the expression of NGFs in the brain. According to this study by I-Chen Li et al. (2), to date, researchers have identified 15 different erinacines (erinacines A-K and P-S). Among these, preclinical studies have shown that erinacine A is particularly effective in reducing age-related neurological diseases. Of significant note here is that erinacine A is only present in the mycelium of lion’s mane, not in the fruiting body. This is crucial for consumers looking to maximize the health benefits of lion’s mane supplements. Many commercial products are made exclusively from the fruiting body, thereby missing out on the powerful effects of erinacine A. Therefore, when choosing lion’s mane supplements, it is essential to look for those that include mycelium to ensure the full spectrum of benefits.
Hericenones, on the other hand, are primarily found in the fruiting body of lion’s mane. They also promote NGF synthesis but not to a degree that erinacines are able to. However, they have been shown to offer other important health benefits. For example, hericenones A and B have been shown to exhibit cytotoxic properties against HeLa cells, a cervical cancer cell line commonly used in laboratory research to discover potential anti-cancer drugs (3). Hericenone L showed cytotoxic activity against certain tumor cells (4). Hericenones C-E and H are able to stimulate NGF synthesis and NGF gene expression with the highest NGF-stimulating ability observed in hericenone E. Hericenones work synergistically with erinacines to enhance cognitive function and protect against neurodegenerative diseases.
Clinical Evidence and Research
The health benefits of lion’s mane mushrooms are supported by a growing body of clinical evidence. Several studies have demonstrated the cognitive-enhancing effects of lion’s mane in both animal models and human subjects.
ratto et al 2019
- Ratto et al. (5) conducted a study using aging mice where researchers used standardized amounts of erinacine A and hericenones C and D extracted from lion’s mane, and confirmed that supplementation was able to improve cognitive abilities in older mice and reverse cognitive decline in mice with signs of weakening.
- A double-blind, placebo-controlled clinical trial with adults 50-80 years old was conducted by Mori et al. (6) where adults with mild cognitive impairment were given lion’s mane supplements for 16 weeks. The results showed significant improvements in cognitive function compared to a placebo group. These improvements were attributed to the increase in NGF levels and the reduction of oxidative stress and inflammation
- Another very interesting randomized, double-blind, placebo-controlled pilot study by Docherty et al. (7) took a different approach and used 41 healthy adults aged 18-45 years. This clinical trial was aimed to study the acute (single dose) and chronic (28 days) effects of lion’s mane supplements. The study found that participants showed faster performance on the Stroop test 60 minutes after taking a single dose of lion’s mane. The Stroop test measures selective attention capacity and skill, as well as processing speed. The chronic effect of lion’s mane supplementation indicated a trend towards stress reduction, as measured using the Stress Visual Analogue Scales.
- Another study by Nagano et al. (8) investigated the effects of lion’s mane on menopausal symptoms, depression, and sleep quality. Over 4 weeks, 30 women were randomly assigned to consume either cookies with lion’s mane fruiting body powder or placebo. Results showed significant reductions in depression and anxiety levels among those consuming the lion’s mane cookies, as measured by the CES-D and ICI scales, which are commonly used to rate depression level. These findings suggest potential mental health benefits, likely through mechanisms beyond just NGF enhancement.
Morri et al 2008
Long story short
Incorporating lion’s mane into your daily routine can be an effective way to support overall brain health and cognitive function. When selecting supplements, it is crucial to choose products that include both the fruiting body and the mycelium in order to benefit from the full spectrum of bioactive compounds, particularly erinacine A. As the scientific community continues to uncover the myriad benefits of lion’s mane mushrooms, it becomes increasingly clear that these fungi hold significant promise for the future of neurological health. Whether through supplements or culinary use, incorporating lion’s mane into your diet can be a powerful step towards maintaining cognitive vitality and protecting your brain as you age.