“All mushrooms are medicinal.”
Traditional Chinese Medicine practitioner, biochemist, author and mushroom expert Martin Powell discusses all things mushrooms, from how extracts are produced, to the secondary metabolites of various species, to how mushrooms produce vitamin D and why you should always cook your mushrooms.
Covered in this episode
[00:58] Welcoming Martin Powell
[02:03] How Martin became interested in mycology and medicinal mushrooms
[04:53] Identifying the correct mushrooms
[10:40] All mushrooms are medicinal
[13:58] How extracts are created
[18:11] Active constituents of mushrooms
[22:31] Do different parts of the mushroom have different components?
[24:34] Lovastatin comes from fungi
[26:01] What secondary metabolites do we need to be interested in?
[31:25] The importance of cooking mushrooms
[35:48] Writing the Medicinal Mushroom books
[37:24] Eat more mushrooms
[39:52] Mushrooms and Vitamin D
[41:29] Grifola frondosa: maitake mushrooms
[42:55] Choosing a quality mushroom product
[46:56] Thanking Martin and final remarks
Andrew: This is FX Medicine. I'm Andrew Whitfield-Cook. Joining us on the line today, all the way from the UK, is Martin Powell. He's a practitioner of traditional Chinese medicine, a biochemist, and the author of Medicinal Mushrooms: The Essential Guide and Medicinal Mushrooms: A Clinical Guide.
He was a lecturer at the University of Westminster for 13 years, during which time he helped set up the Master of Science programme in Chinese Herbal Medicine. And has also taught in Europe, Africa, and Asia.
Today, as well as helping patients, writing, and lecturing, he works as a consultant to leading companies in the natural products industry, with growers and manufacturers, to improve the quality of raw materials in the supply chain, and with leading integrative health clinics on improved treatments for cancer and other chronic health conditions.
I warmly welcome you to FX Medicine. How are you, Martin?
Martin: Hi there, Andrew. Yes, I'm good, thank you. Yeah, all well. A little bit cold over here, but we're coping.
Andrew: Yeah. Now, you've got a Bachelor of Science with honours in biochem. So it's a bit of a jump from biochemistry to mycology. Tell us a little bit about your history, and what first got you interested in mycology and medicinal mushrooms?
Martin: Well, mushrooms have been something which has really sought me out, if you like, in my life. I suddenly wake up one morning and decided that this is what I wanted to specialise in or focus in. Almost quite the opposite, but like a lot of people growing up in the UK and in other English-speaking countries, we tend to have an innate mycophobia. We have an innate wariness of mushrooms. And certainly, when I was growing up and I went for a walk with my parents in the forest, they would always say, "Don't touch the mushrooms."
Martin: Yeah. Because we didn't nearly think about them as something which could be beneficial. We were much more aware and conscious of the potential toxic nature of some of the species. So growing up, I think myself and a lot of people here have an innate wariness, if you like, of mushrooms.
So it was actually quite a surprise and revelation for me when I started studying Chinese medicine. And of course, in Chinese medicine, mushrooms have been a major component of the materia medica for as long as it's been developing, well over 2,000 years. And if you look at the earliest extant materia medica, Shen Nong Ben Cao Jing, that already lists a number of mushroom species and lists most of them in the superior category of herbs.
So rather than being toxic, it's those herbs which can safely be consumed for long periods of time and of which it is said that long-term will lighten the body and confer longevity. So it's a radically different approach, a radically different attitude, if you like, to that which I grew up with.
Martin: That's what really got me started, made me interested. Yeah, it's different. Certainly, particularly in more rural areas, particularly in the farming community, there was an awareness. And if you talked to people of our parent's generation and those who grew up on farms did, in many cases, have an awareness of which mushrooms are good to eat and which weren't. But if you look at the majority of the population, certainly, those in the towns and the cities, there wasn't that same level of awareness.
Andrew: Of course. Right.
Martin: That these are quite strange and potentially toxic. So, yes, the contrast with the Chinese approach, that actually, these are just only not toxic, in many cases, they're incredibly beneficial for our health and well-being.
Andrew: What about the history of medicinal fungi? We know traditional Chinese medicine has used them as medicines. Other cultures use them in more religious or enlightening type rituals. What about historically, the European medicinal array?
Martin: Well, there was, and going back to the Romans, Galen, in his work, he did talk about mushrooms and he included mushrooms as having therapeutic potential at that time. But that knowledge largely wasn't pursued and was, I think, forgotten by the Middle Ages. There was really no extant tradition on its medicinal usage here in Europe and the UK. So, yes, it was something which really we lost touch with. Even going back to the Romans, it was very minor. They weren't seen as a major category of medicinal plants or herbs in their own right.
Andrew: And what about the species that we are very au fait with from the traditional Chinese medicine arsenal, Trametes, Grifola, that sort of thing? Do these occur naturally in the West and in the Americas, or are they more introduced and they had intrinsic, different species?
Martin: Many of these are indeed endemic, although there are native species also in the Americas and in Europe. So one of the most fascinating examples of that is reishi.
Martin: And of course, when we think about most medicinal mushrooms, the quintessential oriental mushroom, if you like, is reishi. But actually, the type specimen for reishi was collected in London.
Andrew: Okay. Right.
Martin: So the species described in the materia medicas and in all publications really on reishi pretty much is Ganoderma lucidum, and the type specimen for Ganoderma lucidum was collected in London in about 1760.
Andrew: Oh, my goodness.
Martin: So Ganoderma lucidum is a native British mushroom. So sometimes when I go to China and I talk to people over there, and I tell them that, "Well, of course, you know that reishi is a British mushroom."
Andrew: And I can just see the applause, the jaws falling aghast.
Martin: Yeah. The initial reaction is, "No, surely not. It can't be." But when one explains to them, of course, following on from that, there is...because Ganoderma lucidum is a British species, what follows from that is actually what is cultivated. What grows naturally in China and Japan is not necessarily Ganoderma lucidum.
Martin: Although, when you read in materia medica, the species is described as Ganoderma lucidum, there are various other Ganoderma species which are now recognised as the ones which grow in China. So actually, what it means is the majority of the textbooks are wrong. So they need to be updated in that regard.
Andrew: There's another question there, and that is, does that mean we've always been using the wrong mushroom?
Martin: Not the wrong mushroom, no. Because there is a lot of overlap between different species, particularly closely related species. So it's no accident that the Chinese mushroom, lingzhi or reishi, to give its Japanese name, was identified as Ganoderma lucidum because they look very, very similar. And indeed, when you look at the actual components of Ganoderma lucidum or the British species and compare it with the Chinese/Japanese species, they're very similar.
Andrew: Oh, okay.
Martin: So from a health benefit therapeutic potential, there's really nothing to choose between them. It's purely based on the taxonomy...
Andrew: Right, got you.
Martin: ...of the species. So, no, we haven't been...we've been calling it the wrong thing.
Martin: And if you look on any bottle of reishi in a store or online, it's going to say Ganoderma lucidum species, because that's what everybody associates as reishi and with that particular mushroom. But strictly speaking from a taxonomical point of view, that's not accurate.
Andrew: And taxonomy with mushrooms is fraught with conundrums. Even mycologists have issues with identification.
Martin: Oh, it's a huge minefield and becoming even more so in recent years with the introduction of DNA testing or DNA sequencing. So that has really led to an ongoing reevaluation of the correct taxonomical position of different species and classification. So it's very much a subject for the ongoing debate, and research has led to a lot of changes in the correct identification of particular species based on DNA sequencing. So it hasn't helped things in that sense. It's made things an awful lot more complicated.
Martin: The term medicinal mushroom is a little bit problematic, if you like, in some ways, because to some degree or another, all mushrooms are medicinal.
Andrew: Right, good.
Martin: And that's because all mushrooms share a common cell wall structure. So unlike animal cells, mushroom cells, in common with plant cells, have a rigid cell wall. So that cell wall is predominantly composed of polysaccharides, which are mostly beta-glucans, and so beta-linked chains of glucose residues. Well, glucose, together with other sugars, so really the hetero-beta-glucans, and almost all of them also have some bound protein component. So call them with various terms, including beta-glucans, or to give it their full name, 1-3, 1-6-beta-glucans, or to include the fact that the majority of them have a protein component, proteoglycans or bound protein polysaccharides.
So there's a variety of different terms which are used to describe these cell wall components from all mushrooms. And the fact that it's not one species or another species or limited to a few species is shown by the fact that its extract from over 650 different species has all been shown to have immunological activity. So even the common button mushroom, or Portobello, or chestnut mushrooms that you buy in every supermarket, those also have been shown to be immunologically active. So it's not to say these are not medicinal. They are medicinal.
Martin: But it's just that certain mushrooms have a higher level of immunological activity, and certain mushrooms have been subject to wider research and scientific clinical testing. And certain mushrooms, as well as having these types of polysaccharide-based compounds in their cellular structure, also have evolved to produce a wide variety of secondary metabolites, which then gives them additional properties as well as the immune-modulating action, which is common to all mushroom species.
So going back to your question, you asked about medicinal mushrooms and whether they were all edible. So apologies for the slight digression there, but if we look at the species which are traditionally referred to as medicinal mushroom species, then most of them are also culinary mushroom species. So species such as oyster mushroom, maitake, shiitake, all of these are culinary species. But then there are other mushrooms such as reishi or Chaga, which are not traditionally culinary mushrooms. So it varies depending on the edibility, of course, of the mushroom.
Andrew: I guess what you're talking about before opens up this question of active constituents. I've seen, even in one species, Trametes versicolor, when you're talking about the two very well-known patented products on the market, and I'm always mindful of, when somebody patents something, it's because they want to make money off it. It doesn't necessarily mean that the original everyday thing doesn't have activities, just somebody's going, "We can do research on this if it's ours." But how far down the rabbit hole do we have to go to look at "active constituents?"
Martin: When I was referring to active constituents earlier, I was actually referring more to the secondary metabolites which are produced by the mushrooms largely for the antimicrobial properties.
Martin: And obviously, we'll probably move on to discuss some of those later, but in terms of the compounds that you mentioned, which are basically extracts of Trametes versicolor, then neither of them is a single molecule. They are just extracts, but they're highly purified extracts.
Martin: So they're extracts where they start off by making a hot water extraction, and hot water extraction is the best way to extract the soluble polysaccharides from the beta-glucans, proteoglycans, which form part of the cellular structure of all mushrooms, including this species.
So if you start off by making a hot water extract, you basically boil the mushroom, and you concentrate the polysaccharides out of the water that is made through that boiling. And then you use different purification techniques to get rid of certain extractions. There, you get rid of protein components, you get rid of small molecules. And then you can narrow down, if you like, the spectrum of molecules that you have got, and that gives you these particular patented or licensed pharmaceutical products.
And actually, quite right, you said, I mean, the whole point of doing that is that you can then commercialise the product. But it's only a portion of the overall activity of the mushroom. And every mushroom extract, if you were to just boil to make a tea of Trametes, as has been done traditionally in different countries, that tea will contain those components.
Martin: It's not a magical thing, they've created something new. What they've done is they've taken a tea, and they've then narrowed down the spectrum of molecules, which they have then selected to use in clinical studies and then, on the basis of those clinical studies, to license and commercially profit from.
Tea, of course, if you're going to create, turn a tea, in terms of the commercial process, it's the first stage. Because if you want something that's in a dried form, you can put into a tablet, you can put into a capsule. Then the first thing to do is you got the liquid, you got the tea, if you like. You can either then dry the whole thing or you can precipitate out a portion of those molecules. And the first stage it's normally done is it's normally done through alcohol precipitation, actually.
Martin: Because the alcohol precipitates the polysaccharides out of the solution. And then you end up with a kind of a sludge. And then you filter that out, and then you dry it, and then you have a crude polysaccharide extract. And then you can further purify that by dissolving it out in different solvents, precipitating again.
Martin: But the basic stage will give you a crude polysaccharide extract.
Andrew: So is it something that we should be really treating each mushroom as to their constituents? For instance, reishi is far more woody than other mushrooms, so it needs different solvents to extract the terpenes and things like that. Whereas Trametes is this gorgeous, velvety, it's a beautiful mushroom, and so it requires different care to extract its medicinal value.
Martin: Yes. It depends on the other secondary metabolites. So going back to the active compounds from mushrooms, the first category that all mushrooms contain are these polysaccharides, the proteoglycans. And the best way to get those, if you want to extract those, rather than just getting them through eating the mushroom and extracting them, if you like, in your guts. If you want to extract them to then use in a product, then the best way to do that is through hot water extraction.
Andrew: Got you.
Martin: But those are only half of the story as far as mushrooms. Many of the most widely revered and most active medicinal mushroom species are widely revered and have the wide range of physiological properties that they do because it's not just the polysaccharides that they contain but also the other secondary metabolites that they produce, which are physiologically active.
So you mentioned reishi. So reishi, yes, it does have very active polysaccharides, which have high binding specificity to receptors in the surface of immune cells, also which have prebiotic effects on the gut's flora.
Martin: So reishi does have those compounds. It does have those polysaccharides. But at the same time, it also produces over 130 different triterpenoid compounds, which largely fall into two families, the ganoderic acids and the lucidinic acids. And the compounds in these categories, the triterpenoid compounds, which give it its wide range of therapeutic properties, including anti-inflammatory, antioxidants, sedative properties, antihypertensive, anti-allergic, antihistamine properties, all of these are properties of the triterpenoid compounds or components on the mushroom.
And because they're terpenes, they're oily compounds, and so they are much more better extracted using organic solvents such as alcohol. So a hot water extract will extract terpenes to some extent but in a relatively low concentration.
Andrew: Right, got you.
Martin: Whereas, if you want a higher concentration of those compounds, you want to use an alcohol extraction. And sometimes if you want high levels of polysaccharides and high levels of terpenoids, then you need a dual extraction.
Andrew: And do ancient texts teach us this differentiation between the different mushrooms?
Martin: The Chinese texts pretty are focused on hot water extraction.
Andrew: Right, got you.
Martin: So they weren't using...well, that's not entirely true. There is a very active category traditionally in Chinese medicine, which is medicinal wines.
Andrew: Right, yeah.
Martin: So if you go into a Chinese herb shop in China, even these days, you'll often see a jar, or a series of jars on a shelf on the wall, and they'll have a whole range of different herbs in them, which are being extracted or slowly extracted over a period of often three months or so in a wine.
Andrew: Got you.
Martin: In a form of spirit. So, yes, they were using a sort of alcohol extraction at that time. But in terms of the individual patient being given a prescription by their practitioner and taking it home, then they would typically do it, use a hot water extraction. They would boil to make it function.
Martin: Well, again, when we consider the relative parts of the mushroom, we also have to consider the context of the actual components. So if we think about the polysaccharides, again, then they're present in every part of the mushroom, because they're structural components of the cell wall. So you've got the same cell wall structure in the fruiting body or in the mycelium. It doesn't make any difference. And if you look at the licensed pharmaceutical products from mushrooms, polysaccharide extracts from mushrooms, they're from both the mycelium and the fruiting body. So, yes, if you're looking for the polysaccharides, looking for the proteoglycans, it doesn't matter what the part is.
But if you're looking at the secondary metabolites, then they do vary, to some extent, between the different parts of the mushroom. Because, in many cases, these secondary metabolites are produced by the mushrooms for their antimicrobial properties. So they are there to help the mushrooms compete with other microbial species, with bacteria, with other fungal species, with nematodes, with multicellular small microorganisms.
Because where are they growing? In the soil or in the rotting tree stump, or wherever it is. They are competing for resources with millions of other microorganisms, not only competing with resources but trying to stop themselves being eaten by other microbes who fancy them for lunch. So in order to compete and stop themselves being another microbe's lunch, they have evolved this ability to produce a wide variety of secondary metabolites.
Martin: So, yeah, I'm sure your listeners are aware that lovastatin is a prescription anti-cholesterol drug. What they're probably not aware of is that it was first isolated from two species of fungi.
Martin: So the reason that this fungal species and other fungal species, other mushrooms, are producing lovastatin is because it is a strong antifungal agent. So if you read the paper written by the London-based group that isolated it, they don't talk about its role in relation to HMG-CoA reductase and cholesterol metabolism. They talk about its role in relation to its antifungal properties.
Andrew: That's interesting.
Martin: So because they're producing these compounds for their antimicrobial properties, they are typically produced in higher concentration by the mycelium, because that's the path of the mushroom, which is growing in the soil or growing in the tree. So if you look at levels of lovastatin production between different parts of reishi, the production in the mycelium is over 10 times higher than in the fruiting body.
Martin: Well, if we think about reishi, to continue that, go back to that point, because we were talking about the terpenes or the triterpenoid components, and those are found largely in the fruiting body. Because those are better components, which are inhibitory or they help to stop the reishi being eaten by insects.
Martin: So they disinhibit or they deter the insects from eating the fruiting bodies, because the reason that the reishi is producing the fruiting body is because it wants to spread the spores. So every mushroom fruiting body is producing millions and millions of tiny spores, which are then spread by the wind to colonise new areas. And it doesn't...in the case of reishi, the fruiting body will continue to produce spores for several months. And actually, the weight of spores produced by a single reishi fruiting body is equal to the weight of the fruiting body.
Martin: So if you have a 200-gram reishi fruiting body, it will produce around 200 grams of spores.
Andrew: They're an incredible thing to behold, the reishi mushroom. When you look at it, you think it's going to be quite weighty. But you pick it up and they're gorgeously light. It's like balsa wood.
Andrew: It's beautiful.
Martin: I mean, they are fantastic. I mean, mushrooms are just gorgeous fun stuff. I mean, they're really a species that's just spectacular. And so going back, in terms of reishi, because it wants to continue to produce these spores to spread and colonise new areas, it doesn't want to get eaten by durgans, if you like. And so it produces these triterpenes, not all of which are bitter, but some of which are very bitter.
Martin: So often, when you have reishi decoction… So levels of triterpenes are higher in the fruiting body than in the mycelium. Levels of the other antimicrobials, secondary metabolites, like lovastatin, are higher in the mycelium compared to the fruiting body.
Andrew: Yeah. So with lovastatin, that was the red yeast rice. Is that correct?
Martin: The red yeast rice or Monascus purpureus is another fungal species which produces high levels of lovastatin and which it is standardised. So in China, particularly, it's been used as a food ingredient for hundreds of years. But now, there are companies which are also growing it for therapeutic use. And the concentration of lovastatin increases the longer it's grown for. So depending on the length of the growth cycle, then you can standardise the product that's produced for a particular concentration of lovastatin.
Andrew: Right. What about other secondary metabolites that have medicinal value though?
Martin: So many mushrooms contain...there's a wide variety of secondary metabolites. So lovastatin is produced by many mushroom species. Another antifungal agent which is produced by shiitake is eritadenine. So eritadenine is produced by shiitake, and interestingly enough, it also has a role in controlling cholesterol levels but by a different enzymatic pathway.
Martin: I think it's S-adenosyl-L-homocysteine hydrolase that it inhibits.
Martin: So again, the reason shiitake produces eritadenine is because it is an antifungal agent. So it's an example of another antifungal agent produced by another mushroom, which also has a role in terms of cholesterol metabolism.
Then we have other compounds such as ergothioneine, which is produced by, particularly, oyster mushrooms and by porcini. So these are both, of course, delicious culinary mushrooms, and ergothioneine is an important antioxidant amino acid, which is required by our body and our tissues. And the reason we know it's required by our body is because it's a specific transporter molecule in our cell membranes.
Martin: So we have a specific molecule to make sure it gets into our cells, but our body doesn't produce it. We have to derive it from our diets. And the richest sources of ergothioneine are mushrooms, particularly oyster mushroom and porcini mushroom.
Andrew: Got you.
Martin: So that's another example of a secondary metabolite, which is found in high concentrations in red blood cells, in bone marrow, in seminal fluids, in the eyes, so all of these areas where we need to make sure we have high levels of antioxidant capacity to protect against oxidative damage. Ergothioneine is an important antioxidant amino acid that is required in those areas, which we have to get from our diet, particularly from mushrooms.
Martin: Enokitake produces very...there are no therapeutic secondary metabolites that have been researched in relation to enoki mushrooms. What's been researched in relation to enoki, enokitake, or Flammulina velutipes are the polysaccharides and also the proteins. So there are small protein molecules from enokitake which, alongside the polysaccharides, have also been shown to have immunomodulatory properties.
Andrew: Got you.
Martin: One second. It's not that enokitake doesn't produce secondary metabolites. It does. There's one of them, flammutoxin, which is actually a toxic compound produced by enokitake, and it's toxic not only for other microbial species but also for ourselves. And that's the reason why it's produced in relatively very low concentrations. So eating enokitake is not dangerous, typically, but it is a good reason why all mushrooms should be cooked.
Martin: And I'm often asked about whether to eat mushrooms raw or cook them, and I say that you should always cook mushrooms. Because not only does the cooking process help to break down the cellular structure and then release the active compounds, but it also, in many cases, will break down toxic compounds from the mushroom where they're present. One example is enoki, Flammulina velutipes. Another one, interestingly enough, is shiitake.
Martin: There's a condition called shiitake dermatitis, which, as its name suggests, is a skin rash which people get from eating lots of shiitake. And it's been reported from many countries around the world, obviously, first of all, from Japan, but now there have been reports from many countries in Europe. And in every case, though, it has been from eating lots of raw shiitake mushrooms. So always cook your mushrooms.
Andrew: What I think is really interesting is, as a culture, in the West, we seem to be really restrictive as to what's acceptable, whereas traditional Chinese and Japanese culture has an expansive array of these culinary mushrooms. It seems like we've missed out. I mean, another one, which I lovingly call snot on a log, Tremella fuciformis. I mean, that's just...it's a gorgeous mushroom.
Martin: It's a gorgeous mushroom, and it is also a very… I mean, I hesitate to use the word delicious culinary mushroom, because it has no flavour. So, I mean, it's hard to call it delicious, but it is a very highly valued culinary mushroom in Eastern cookery. Particularly, because it has no flavour, you can just put in soups, you can just use it in desserts, and also, it has a wonderful texture. So it has that lovely kind of crunchy texture to it.
So, yeah, I mean, mushrooms are fascinating. So, yeah, Tremella fuciformis is an interesting mushroom because it is not growing on the log. It may look like it's growing on the log, but it's not. It's actually growing parasitically on another fungal species.
Andrew: I did not know this.
Martin: So it grows, it travels in a single cellular film over the surface of the log until it encounters its preferred host. So when it finds the other fungal species growing and digesting the wood quite happily, it then penetrates into that other fungal species and uses its nutrients to produce its fruiting body. So it's an example of a mushroom which doesn't produce antimicrobial, antifungal secondary metabolites.
Martin: Because why would it? I mean, it doesn't want to kill its host.
Andrew: That's really interesting.
Martin: Yeah. They come in all shapes and sizes. Amazing.
Andrew: There are so many. I mean, there's way too many to cover. We could go on and on, I mean. But we haven't spoken about maitake. I must say here, I was so impressed with your book. I've got quite a few medicinal fungal books, and yours shined. Yours and Christopher Hobbs' are my favourites. But it's so clear, it's so well-set-out. You've obviously done a lot of work. How long did that take to write and to form?
Martin: I wasn't counting the time. Or I might have stopped, I don't know.
Andrew: That's got to be a labour of love, yeah.
Martin: Yeah. It took a while. But I mean, I was...I really wrote that book almost partially for myself. Because I ask other practitioners here, to really...because I wanted to answer the questions. I wanted to try to answer the questions in terms of, any individual patients, what was the best mushroom to give that patient? What was the best form to give the mushroom in? And what was the appropriate dosage?
Martin: So as practitioners, that's what we want to know. And I really wanted to go back and really look at all of the evidence and try to come up to what I felt was the best understanding of what the answers to those questions were in relation to different conditions and different species.
Martin: I always encourage people to eat more mushrooms.
Andrew: Yeah, I'm with you. Totally with you.
Martin: I give a lot of lectures in the UK and further afield, and one thing I often say, the main sort of take-home message from this lecture basically is just to eat more mushroom. Because even through culinary, even through dietary consumption of mushrooms, there's very clear evidence that just by eating mushrooms on a regular basis, that, in itself, will have a positive impact on overall health and well-being. There have been a number of epidemiological studies looking at the correlation between incidence, or the frequency of mushroom consumption and the risk of developing cancer.
Martin: And showing that people who develop cancer were statistically eating less mushrooms. It doesn't mean that everybody who eats mushrooms regularly is never going to develop cancer, or everybody who developed cancer wasn't eating enough mushrooms. But when you look at large bodies of people, statistically, there's a strong inverse correlation between those two things.
Andrew: Got you.
Martin: So we know from that and also from other studies just looking at changes in immune parameters from dietary mushroom consumption in smaller bodies of participants that just dietary consumption of mushrooms will have a positive impact on our health, partly because they have an impact through the immune system and receptors on the surface of major cachectic immune cells, partly because of their impact on the gut flora and their prebiotic effect.
So, yes, I always encourage people to eat more mushrooms. But sometimes our health can… and if we are in a healthy state, if we're in a balanced state, then eating more mushrooms will help to maintain that balance, will help to increase our resistance to infections, viral conditions, or to cancer. So in those cases, yes, just eating more mushrooms if we're healthy.
Andrew: One thing we haven't covered, we haven't covered Grifola, again, but one thing we haven't covered is ergosterols, the vitamin D. I mean, they've even irradiated slices of, I think they were portobello mushrooms in Perth, to something like 50,000 IU.
Martin: They convert ergosterol into vitamin D2.
Martin: Which the name I forgot, ergocalciferol.
Martin: So mushroom-contained ergosterol can part parts in the cell membrane. But then on exposure to UV light, as you say, they convert that into vitamin D2. So, yes, if you are harvesting mushrooms and growing outside, then, of course, they will have been exposed to UV light, sunlight, but if you're buying mushrooms in the supermarket, then they've quite possibly been grown in the dark.
So in that case, it's always advisable, before you cook them, to expose them on your windowsill and UV light for around half an hour. And yes, commercially, when they're developing vegan vitamin D supplements, they will pulse them with UV lights at a much higher concentration. But even exposing them to sunlight on the windowsill for half an hour will lead to an appreciable increase in vitamin D concentration. Ideally, if you expose them, that you cut it down so the gills are up, because that increases the surface area.
Andrew: Right. Okay. Thank you very much for that. Good tip.
Martin: Grifola frondosa. The research in relation to Grifola hasn't really looked and detailed out specific secondary metabolites. It's been focused on extracts. However, when you look at what was actually used in the clinical studies, in every case, it was a combination of a low dose of extract with a high concentration of a whole mushroom powdered.
Martin: So whether it was studies for cancer, or studies for PCOS, or studies for blood sugar control, in all of those cases, they were using...I mean, if we look at the cancer studies, they were looking at dosage from 35 to 150 milligrams a day of a highly purified extract, with a 4 to 6 grams a day of dried mushroom powder.
Andrew: Got you.
Martin: So a lot of mushroom powder being consumed with a small amount of extract. So it's incorrect to say that the therapeutic benefits of mushroom and the clinical studies have really looked at extract. They've used and they've looked at the fruiting body supplemented with a small amount of extract.
Andrew: Well, I hope we all embrace the culinary mushrooms that you've enlightened us with. But given that we'll be seeing patients in our clinics, what really do we need to be concentrating on to choose a quality product?
Martin: Yes. There are different forms of the mushroom which are present in products, and those are...you can just have fruiting body powder or powdered fruiting body, which, yes, is not without its benefits, as we've said, but which particularly is mainly appropriate for culinary mushrooms, because we can digest those. It's not so appropriate for things like reishi or Chaga, which are hard and woody mushrooms or harder, woody mushrooms, which are not so digestible.
Andrew: Got you.
Martin: And so that's generally, yes, that's one particular form. Another form are the extracted products which are widely available also. And the extracts fall into two categories, hot water extracts, which are rich in polysaccharides for immunomodulation, or alcohol extract, which will have higher numbers of terpenes, more anti-inflammatory activity, in particular, and dual extracts, which combine the two.
And then you have products which are mycelial biomass products, which are also referred to as full spectrum products, which are...they contain...what they're made of is like a fermented grain, typically brown rice, but sometimes sorghum, or oats, or corn. And what the production there is that the grain is inoculated with the mushroom mycelium, which grows and colonises the substrate. And then after the mushroom has consumed the vast majority of the substrate, the whole mycelial biomass, so the residual substrate together with the mushroom mycelium, and importantly, the secondary metabolites which have been secreted by the mycelium into the substrate, that is all harvested, and that's then used to produce the product.
So those types of products will typically have higher levels of the antimicrobial secondary metabolites but lower levels of the polysaccharide, the immune-modulating polysaccharides or terpenoid compounds, which are found more in the fruiting body or produced in high concentrations through extracting.
Andrew: You raise an interesting point there about this bidirectional secretion, if you like, or use of the substrate and that the secondary metabolites may indeed be secreted into that substrate. So having some substrate along with the mushroom is not necessarily a bad thing.
Martin: No. It's a fermented product, which we're all now increasingly aware of the health benefits of fermented foodstuffs also, particularly from the specific point of view of our gut flora. But also, these compounds that are produced by the mushrooms, in many cases, are produced, as we were saying, because they are antimicrobial. So as I mentioned, in reishi, the level of lovastatin produced by the mycelium is over 10 times, more like 15 times, the concentration of the fruiting body.
Martin: So where the antimicrobial components are an important active part of the mushroom, an important part of the mushroom's overall therapeutic activity, then, yes, they will be found in higher concentration, typically, in the mycelial biomass product.
Andrew: There's so much to learn, Martin. I would love to have you back on the show to talk maybe about specific entities. We never delved really into the prebiotic effects of mushrooms, which I'd love to cover later if we could. Could we invite you back onto FX Medicine at a later stage?
Martin: Yes, we could certainly do that.
Andrew: And thank you so much for teaching us, just gleaning a little bit of your expansive experience from this from using medicinal mushrooms in your history as a practitioner. I really can't thank you enough. It's been so great to speak to you. I've been wanting to have you on the show for quite some time.
So thank you very, very much for taking us through at least the first chapter of what we'll speak about in subsequent podcasts. Thanks very much for joining us today.
Martin: You're very welcome.
Andrew: This is FX Medicine. I'm Andrew Whitfield-Cook.