Hericium: The Nerve Regenerators
Hericium coralloides and H. americanum (ramosum) & H erinaceus
Common Names: Bear’s head tooth , Comb tooth, Bear’s head Hydnum, Lion’s Mane, Pom Pon, Monkey Head, Yamabushitake, Houtou …
There is an almost visceral jolt through my body at the sudden sight of a great edible or medicinal mushroom seen from a distance. For those who seek the Bear’s Head Tooth or the similar Comb Tooth, finding these mushrooms is the essence of the jolt. Picture a clean white mass of mushroom growing attached to the dark gray bark of a dead standing Beech tree in the shaded understory of a mixed Beech and Hemlock woods. The purity of the whiteness contrasting with the gloom of the background is like finding a gold doubloon lying exposed on a black sand beach in the sun. It captures your attention in a split second.
Another aspect of the Comb Tooth that grabbed the attention of the scientific and healing community was the publication of the discovery of the compounds named Erinacines, described as potent stimulators for the production of nerve growth factor. The excitement paralleled the general level of anticipation from research indicating that these nerve growth factor stimulators might play a role in treatment of many types of nervous system disorders including Alzheimer’s Disease and other forms of dementia.
The genus Hericium in the Eastern US is represented by three species that can be a challenge to tell apart by features or accepted name. H. erinaceus, known as the Bear’s Head, Lion’s Mane, or Pom-Pom is arguably the best known member of the genus in the US and worldwide. Most of the medicinal research has been carried out with this species and it is also the easiest of the three to identify. This species is unusual in Northern New England and increasingly common the further south one travels on the eastern half of the US. The other two, now known as H. americanum and H. coralloides, are instantly seen as members of this genus, but depending on the book you consult or the age of your knowledge you might call them one of several confusing and overlapping scientific names. Fortunately this is a case where the name confusion need not getting the way of enjoying these mushrooms for food or appreciating their medicinal attributes. All three are excellent and safe edibles, especially when collected and cooked young, and white. There is evidence that they share many of the same medicinal components; the nerve-stimulating factors, erinacines have been isolated from both H. erinaceus and H. coralloides.
Description: This is for both H. americanum and H. coralloides.
Fruiting bodies arise from a narrow attachment on wood and maturing from 4” to 12” in diameter, roughly globose to irregular in shape. Each mushroom is pure white and fades to reddish brown and brown, especially at the tips of the teeth. Young fruiting bodies are at times pink to almost salmon. Each starts from a compact central stalk that immediately branches out ending in clusters of short icicle teeth. In H. coralloides the teeth on a mature mushroom are between 0.3-1.0 cm. long and in H. americanum, the spines are longer, generally 1.0-2.5 cm long. H. coralloides tends to branch more and therefore assume a spread-out and diffuse appearance. H. americanum is often more dense with less branching and retains the look of a compact mass on the side of a tree or log. The spine of each droop down in graceful falls and it is along the exterior surface of these spines where the white spores are matured and released.
H erinaceus differs from the two other species in the lack of branching of the stem and having longer teeth. All of the long, pendulous icicle teeth arise from a simple, unbranched, tough central stalk. The individual teeth are up to 6 cm. long and the whole fruiting body can be over a foot in diameter and is generally solitary on the stumps or logs of trees.
H. coralloides has been known as H ramosum until recently and many older field guides refer to it as such. Those Hericium with longer teeth had been known as H. coralloides before but know are known as H americanum. If you feel confused by this, you are in very good company in the mushrooming world. The main consideration is that you would not go wrong to pick and eat fresh specimens of any from this group.
Occurrence and habitat:
Look for the Comb Tooth following periods of wet weather as summer cools down and the early fall chill comes into the night air. In Maine and Vermont as well as Northern New Hampshire, this means late August and on into September with the season continuing through the fall until hard frost. In a dry year the dead-standing trees may not fruit, but the logs and branches lying on the forest floor will still produce.
ll three species favor hardwoods tree species with Beech, maple and birch being the preferred in this part of the world by H. americanum and H. coralloides.
H. erinaceus is often found growing on oak, beech or maple and is not typically found on birch.
Ecological information: The Hericium are primarily saprobes or weak parasites invading a living tree at the site of a wound and colonizing the dead heartwood. They can also live on and break down dead wood logs and branches. The fungus appears to be quite aggressive in its ability to degrade wood. Within a very few years from the onset of fruiting, a foot diameter log is already broken down to the point that the mushroom no longer produced mushrooms.
Edibility: Unlike many groups of fungi where you absolutely must know the species to determine edibility with certainty, it really doesn’t matter which species in the genus Hericium you have, all are very good edibles and have no history of causing difficulties for the consumer. Hericium are best eaten when young, tender and pure white. As they age, becoming cream colored or with brown teeth, they are less desirable and, like many fleshy mushrooms are prone to be colonized by mold or bacteria that could render them toxic. We would not consider eating hamburger left out for a couple of days; the same consideration should be used for mushrooms. Eat them when they are firm, fresh and show no signs of decay. Hericium have the reputation for cooking up with a slight taste of seafood, some say lobster. I find them a welcome addition to a milk or cream-based chowder along with whatever else you like in this type of soup, whether potatoes, corn, haddock…
Potential toxicity: There have been no significant problems with people eating this mushroom or using it as a dietary supplement.
Look alikes: As mentioned above, all species in the genus Hericium found growing in the US are considered good edibles. This very distinctive group may be difficult to tell apart within the genus, but have few if any real look alikes. The species of Hericium that include H. coralloides, H. americanum (and the other species names given to this group including H. ramosum, H. laciniatum), are quite similar in appearance and somewhat variable. The medicinally better-known H. erinaceus is found in Southern New England but is more common further south and even into the tropics. On the West Coast, H. abietis is found on various conifer species and is also edible and good.
Note: Though I recommend without hesitation that, for the purpose of edibility, the diner can lump together the related forms of Hericium, I find myself on less firm ice when making a similar statement regarding their medicinal values though I am inclined to do so. Though the majority of research into the medicinal properties of Hericium has been carried out using H. erinaceus, several studies that compared the polysaccharide components and antitumor properties of H. coralloides/ H. laciniatum with H. erinaceus have shown that while there are some differences in the sugar make-up of the polysaccharides, their antitumor effect in studies using mice were very similar as were the reported stimulation in the production of immune factors such as T cells and macrophages (Wang et al, 2001). In addition, the erinacines isolated from H. erinaceus and seen as a nerve growth stimulator have also been isolated from H. ramosum/ coralloides (Saito et al, 1998). These two findings lead me to suggest that for the use of Hericium as a dietary supplement, it would be similarly health promoting to use any of the species mentioned here and found growing in the Northeastern US.
Folk or traditional: Hericium species have been used as food in a number of areas around the globe for many years, most notably in China and Japan. The medicinal use of these mushrooms has been more limited until recently and this may be due primarily to the relative rarity of the fruiting bodies in the wild. Most areas do not have Hericium as a commonly or easily found species. Since the artificial cultivation of this wood degrader was mastered over the past 20 years, the mushrooms have become more available year around for research and use.
Current uses: Powdered fruiting body and mycelium are for sale from a number of sources as dietary supplements and recommended for use as immune stimulants and for improved brain functioning. The mushrooms are available from a number of sources, generally as capsules of dried mycelium. The mushrooms are not currently approved by the FDA for the treatment of any medical conditions.
Areas of research:
Nerve Growth Stimulant: The most exciting aspect of the medicinal value of Hericium has been the discovery and exploration of the factors now called erinacines that have shown the ability to stimulate the production of nerve growth factor (NGF) in animal trials and hold forth the promise as possible therapeutic agents in the treatment of Alzheimer’s disease and other neurodegenerative disorders (Yamada et al, 1997). The erinacines are diterpenoid compounds that are potent stimulators of the production of NGF and have been shown to increase some neurotransmitter levels and to increase levels of NGF in the brains of experimental rats given doses of erinacines into the stomach (Shimbo, Kawagishi & Yokogoshi, 2005). However, in a study using human brain astrocytoma cells (Koichiro et al, 2008) it was determined that while a methanol extract of H. erinaceus powder stimulated an increase in NGF as evidenced in the assay of RNA associated with NGF production, the application of purified erinacines did not. This leaves in question the exact mechanism of NGF stimulation by this mushroom in human brain cell lines, but evidence shows repeatedly that Hericium is an effective NGF stimulator.
A recent human clinical study carried was out in Japan with a group of Japanese men and women age 50-80 reported and diagnosed with mild cognitive impairment and treated with H. erinaceus fruiting body powder given orally. The results of this double-blind, placebo-controlled study showed that the treatment group subjects had significant improvement in cognitive function at 8, 12 & 16 weeks and also showed that the improvement did not last beyond 4 weeks following the discontinuation of the mushroom powder. The test subjects were given 1 gram of dry powder 3 times per day (Mori, et al, 2008). All of the 14 test subjects showed improved cognitive functioning at 16 weeks as compared to 5 of 15 placebo subjects.
Antitumor and Immunomodulatory: A number of studies utilizing hot water extracts of Hericium species have shown stimulation of and increased effects on a number of components of immune functioning including:
- Increased activity of macrophages and release of nitric oxide by rat peritoneal macrophages and an indication that this was due to the water extract enhancement of the expression of the genes for nitric oxide production (Son et al, 2006).
- A hot water extract of Hericium used with mouse splenocytes grown out with Yac-1 lymphoma cells showed indirect activation of natural killer cells as evidenced by an increase in interlukin-12 and interferon (Yim et al, 2007).
- Polysaccharides extracted from culture broth of two species of Hericium (H. coralloides and H. erinaceus) both shown to increase the levels of T cells and macrophages and to be active against lung cancer tumors in mice (Wang et al, 2001). In another study by the same author, it was shown that the ant mutagenic (enhancing the resistance of cells to become cancerous in the presence of cancer-causing agents) action of the extract from the fruiting body was greater than that of the extract from cultivated mycelium and that an ethanol extract was better than a water extract for cancer protection in this species (Wang et al, 2001).
Additional bioactive and antitumor polysaccharides
Diterpinoids such as Erinacines and related cyathanes (Kenmoku, 2002)
Ergosterols; vitamin D-2
Collection, Preparation and use:
Collect any of the Hericium species as fresh, firm pure white mushrooms. In wet weather they can become quite waterlogged and in such cases need to be cooked or dried quickly to avoid spoilage. As they age, the spines become cream-to-yellow and then brown. This is an indication of an over mature specimen and the flavor and texture would not be as good as in a young mushroom. Consider the option of eating the young prime specimens and preserving any that are older, yet without signs of spoilage.
As a functional food, Hericium is great in a stir-fry, sautéed with pasta sauce or used as an ingredient in soups. For H. erinaceus the stem base can become quite tough and requires long, slow cooking. It might be best saved for drying.
For preparation and preservation for use as a dietary supplement for immune support or nervous system support, dry the fruiting body and powder it for use in capsules or added to soups and broths. For therapeutic use 1-2 grams per day or as recommended by your health care provider. Alternatively, this would be a great mushroom to prepare in a double extraction tincture as research has shown that the ethanol extract contains the active nerve stimulators.
For additional information on Hericium, please refer to my book Mushrooms for Health; Medicinal Secrets of Northeastern Fungi (Link)