Fomitopsis betulina (previously Piptoporus betulinus), commonly known as Birch polypore, or Birch bracket, or Razor Strop, is an edible polypore mushroom that exclusively grows on birch trees. The name of the mushroom is derived from its host tree and is found on dead birch, occasionally as a parasite on living trees. 
This brown rot, Basidiomycota, bursts out from the bark of dead birch, revealing its fruiting bodies. By the time the fruiting body appears, there is extensive decay in the tree. The fruiting body is tough and woody and remains in the host tree for years.
Fomitopsis betulina is called polypores because of the numerous small pores underneath them. These are the sites for releasing spores. After the mushroom has released its spores, the mushroom is no longer edible.
Birch polypore in history
This potent white bracket fungus has been utilized by humans for thousands of years and has been widely appreciated in folk medicine.
The earliest evidence of the use of Birch Brackets dates back to 5000 years. In 1991, German hikers discovered a 5000-year-old mummy, nicknamed Ötzi the iceman, buried in the ice. This ancient body of a herder, who lived and died in the European Alps, had some possessions preserved along with him.
The now-famous mummy had two pieces of polypore fungi with leather strings through them. One of these was found to be the Birch bracket. The frozen corpse also had parasitic intestinal worms (Whipworm) that can be cured with polyporenic acid present in Birch polypore. Scientists believe that he may have used the mushroom for medicinal purposes. 
Taxonomy of Birch Polypore
In taxonomic history, birch polypore was originally described by Jean Bulliard, in 1788. He named the fungus the binominal scientific name, Boletus betulinus. Later in 1881, it was transferred to the genus Piptoporus by Finnish mycologist Petter Karsten. In 2016, the fungus was reclassified to Fomitopsis, as the species closely resembled it. Betulina refers to the genus of the host plant, Betula.
How to identify a Birch Polypore?
Birch polypore mushrooms are easy to identify and are found anywhere birch trees are present. They are annual and are found emerging from the birch bark in spring and summer.
There are very few similar-looking mushrooms that grow on birch trees. Nonetheless, here is how you can identify the Birch polypore.
The first key to identifying a Birch polypore is to identify the host tree. Birch trees have light-yellow, light-gray, or white bark with dark horizontal lines. You can often find thin papery plates peeling out of it. The leaves of the birch tree are triangular, with a serrated margin and two rounded corners.
The cap of the fruiting body is cushiony and pancake, kidney or hat-shaped that looks like a shelf or bracket. The top surface is grey-brown in color and smooth.
The white to tan colored pore surface on the underside has small and regular pores. The mushroom fruiting body can grow singly or in small groups and is covered with a glabrous and lacquered crust.
The mycelium of Fomitopsis betulina is white, downy, and similar to a felt, and branches out in a threadlike manner. The mushroom is attached to the tree by fat and short stalks.
Birch polypore can measure up to 30 cm in width and 6cm in height.
Birch polypore spore print is white.
Birch polypore is an edible medicinal mushroom with a bitter taste.
Birch polypore locations
Birch bracket mushroom is commonly found in countries around the world that have birch trees. These are found growing in the northern temperate forest across Asia, Europe, and North America. 
Health benefits of Birch Polypore
The health benefits of birch polypore have been extensively studied with ample evidence supporting it.
Here are the health benefits of birch polypore that have been backed by modern research.
1. Anti-inflammatory action
Polyporenic acids A and C are promising anti-inflammatory agents in Birch polypore mushrooms. They have shown inhibitory activity towards Angiotensin-Converting Enzyme (ACE).
The mushroom extracts strongly suppress the activity of hyaluronate lyase and 3α-hydroxysteroid dehydrogenase, while weakly inhibiting cyclooxygenase-1 (COX-1). These compounds are implicated with inflammation.
In a 2003 study, researchers found that six lanostane-type triterpene acids isolated from the fruiting body of Fomitopsis betulina reduced ear swelling induced by inflammation in mouse models by 49-86%. 
2. Antiviral effects
Betulinic acid, a triterpene isolated from Birch polypore, was found to have significant inhibitory actions on Human Immunodeficiency Virus (HIV-1). The compound was found to block viral maturation and could be a noteworthy and novel anti-HIV reagent 
Another study conducted in 1981 found that the ethanol extracts of the mushroom protected Chick Embryo Fibroblast (CEF) cells from the vaccinia virus. 
Polyprotic acids and nucleic acids that were extracted (water or alcohol extraction) from Birch polypore caused induction of substances similar to interferon, an inhibitory protein released by the body in response to a virus. [8, 9]
Similarly, ethanol extracts obtained from Fomitopsis betulina were found to protect mice from lethal infection by Tick-Borne Encephalitis.
3. Bactericidal effects
Several studies have evaluated the antibacterial activity of Birch polypore mushrooms against gram-positive and gram-negative bacteria.
Polyporenic acid has been found to inhibit the growth of several bacteria including Serratia marcescens, Staphylococcus aureus, Pseudomonas aeruginosa, Mycobacterium smegmatis, and Bacillus subtilis. 
Piptamine, isolated from the submerged cultures of Birch Polypores, has demonstrated bactericidal actions against E. coli, Enterococcus faecalis, S. aureus, and B. subtilis.
The antibacterial activity of another active compound isolated from Fomitopsis betulina (3β-acetoxy-16α hydroxyl-24-oxo-5α-lanosta-8-ene-21-oic acid) against E. coli, S. aureus, and B. subtilis has been exhibited in other scientific studies. 
4. Anti-tumor effects
The fruiting bodies of Piptoporus betulinus can be utilized as an anti-cancer agent, which was examined in human lung carcinoma, human colon adenocarcinoma, and human breast cancer cell lines.
In this 2016 study, the mushroom extracts inhibited the proliferation of tumor cells in a dose-dependent manner. The most prominent anti-proliferative activity was demonstrated by the ethanol extracts of Birch polypore. 
The other tumors to benefit from Birch polypores are rat gliomas, and human tumors such as thyroid carcinoma, cervical adenocarcinoma, T-cell leukemia, multiple myeloma, rhabdomyosarcoma, and medulloblastoma.
The anticancer effects of Birch polypore are achieved by various mechanisms.
Alcohol and water extracts of cultivated fruiting bodies of Fomitopsis betulina have been associated with the following effects on tumor cells:
- Inhibition of the proliferation of cancer cells by interrupting the cell cycle
- Inhibition of the synthesis of DNA, which is required for the proliferation of tumor cells.
- Decreasing the size of the tumor by inducing the lysis of cancer cells.
- Inhibition of the metastatic spread of tumor cells.
- Decreasing the viability of cancer cells.
- Inhibiting Matrix Metalloproteinases (MMP) and its subtypes, the enzymes that help tumor cells degrade and penetrate the extracellular matrix.
- Inducing the death of cancer cells by apoptosis.
- Decreasing the adhesion of tumor cells. 
Water extracts of Birch polypore have antioxidant capacity. α-, β-, γ-, δ-tocopherols, β-carotene, ascorbic acid, and lycopene derived from the mushroom have reducing powers and DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) scavenging activity. It can also inhibit α-carotene bleaching. 
Likewise, bioactive compounds like protocatechuic acid vanillic acid, and p-hydroxybenzoic acid extracted from fruiting bodies of Birch polypore also have potent antioxidant properties. 
The fungicidal effect of Birch polypore mushroom has been demonstrated in scientific studies. 
The Piptamine isolated from submerged culture of F. betulina can inhibit the growth of fungi like Candida albicans, Aspergillus fumigatus, Saccharomyces cerevisiae, Sporobolomyces salmonicolor, Kluyveromyces marxianus, Rhodotorula rubra, and Penicillium notatum.
Dichloromethane extract obtained from Fomitopsis betulina has been found to inhibit Aedes aegypti in a study published in 2008. 
Apart from its ability to kill or suppress the growth of various microorganisms, Birch polypore mushrooms have also been associated with neuroprotective benefits.
The ethanol and ether extracts of the mushroom protected the neurons against damage induced by excitotoxicity, cisplatin, and trophic stress on 10-day-old mouse neurons. 
A type of white blood cell (neutrophils) obtained from the peripheral blood of humans was subjected to the water extracts from the fruiting bodies and mycelium of Birch polypore mushroom.
This resulted in the activation of the white blood cells and the production of reactive oxygen species, which play a crucial role in immunomodulation. 
How do you consume birch polypore?
A question that pops up in most people’s heads is: Can you eat Birch polypore raw? Wild medicinal mushrooms like Birch polypore may be edible but must be cooked before consumption.
Young Birch polypores can be roasted after slicing and marinating them. You can also dehydrate the mushroom and grind it into a fine powder. This can be added to many foods and beverages or stored in a cool dry place for future use.
Can you make tea from birch polypore?
Older, wild birch polypore is tough, woody, and rubbery in consistency and mushroom tea is a good way of extracting flavors and nutrients out of them.
To make tea from birch polypore, clean the mushroom and place it in a pot of water. Let the water simmer for a few minutes, to extract its medicinal compounds.
Bring the water to a boil and reduce the heat to let it simmer again for 15-20 minutes. Make sure you do not simmer for long as this may make the tea bitter.
You can drink the birch polypore tea right away or refrigerate it for later use. It can also be frozen into ice cubes, making a perfect cup of iced mushroom teas or even fruit smoothies.
Is birch polypore hallucinogenic?
There are a few reports of the psychoactive effects of Birch polypore. However, more studies are required to confirm it.
How do you dry a birch polypore?
If you buy too many mushrooms at a time, or if you go mushroom foraging and pick more mushrooms than you can eat, you can preserve them for later use by drying them out.
Begin by picking a good amount of birch polypore and cleaning it with the help of a brush or a blunt knife. Do not use water for cleaning. If you need to remove stubborn dirt, use a damp paper towel, albeit sparingly.
Cut the mushroom into 3mm thick slices. The thicker the slice, the longer it takes to dry them
You can dry the mushroom using a mushroom or plant dryer, or an oven. Lay them out on baking sheets and cook at 150 degrees for one hour. Turn over and cook for another hour.
You can also attach the mushroom to a string of yarn and hang them in a warm and well-ventilated place. You will know the mushrooms are dried when they lose their elasticity.
When stored properly in a dry container, away from the sunlight, these dried mushrooms will last for years.
Chaga vs Birch Polypore – What’s the difference?
The difference between Chaga mushrooms and Birch Polypore is that not all Chaga mushrooms grow on birch trees.
Chaga, or Inonotus obliquus, is another well-known medicinal mushroom that grows on the Birch tree. It is a brittle mushroom with a charcoal-black exterior crust (known as the sclerotium). While the Chaga mushroom does grow on Birch trees, it is not limited to it. Chaga is also found in Alder, Aspen, and Elm trees in the cold climates of the Northern hemisphere.
While both mushrooms contain the same medical compounds, notably the triterpenes, Birch polypore contains a lower amount of betulin and a higher quantity of lupeol than Chaga in certain extracts. 
The birch polypore also contains an anti-microbial or anti-inflammatory compound, called taraxasterol, which is not found in Chaga.
Birch polypores are types of polypore mushrooms that are found growing exclusively on birch trees. This brown to white hat-shaped fungus may be tough and bitter to taste but is loaded with medicinal benefits.
Several scientific research has claimed the health benefits of Birch such as anti-viral, anti-bacterial, anti-fungal, anti-parasitic, anti-inflammatory, and anti-oxidant.
The mushroom has also exhibited immunomodulatory and neuroprotective effects. Whether you intend to take the mushroom powder or make a tea out of it, either way, it is a powerfully healing fungus.
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