0:00 Oyster mushrooms make about 100 times more vitamin D than your routine field mushroom and we need relatively good levels of vitamin D particularly for our immune system. But the big thing is they are making vitamin D just like us in response to sunlight. But most mushrooms grow in the dark. So actually laying out your mushrooms in a bit of sunshine is enough to raise the level of vitamin D very dramatically. However, the way you prepare your mushroom does have an impact on what stays in the mushroom. >> So, what should I be doing? Robin May is a worldleading expert on fungi and their interactions with the immune system. He's published hundreds of papers and is a professor of infectious diseases at the University of Birmingham, an acting chief scientific
0:45 adviser to the UK government's food standards agency. Mushrooms are really important for influencing the microbiome of the gut and of course the good microbiome can have a very strong positive effect on your immune system. >> Are there any funguses growing in my gut? >> Yes. And historically people said fungi growing in your gut bad thing. However, it's really only in recent years that we've started to understand a bit more about some species that are quite good to have in your gut helping to keep our immune system in balance. One of the big things I hear is about brain aging. Any evidence around this? >> Some extracts of lion's mane fungus protect your brain. It stimulates nerve growth, demonstrating improvement in cognitive decline.
1:30 >> If someone's listening to this and saying, "I want to add more mushrooms to my diet." What would be your one tip? >> Can I do a tip and an anti-tip? >> Yeah, you do it. >> So, my anti- tip is Are mushrooms more closely related to humans than to plants? >> Uh, yes. >> Do some mushrooms contain vitamin D? >> Yes. >> And finally, what's the biggest myth that you often hear about mushrooms? >> I think it's the weirder the mushroom, the better it is for you. Caution against that one. >> Not true. >> No. Stick to the mainstream, I'd say. >> Is that only cuz you might die by eating the weird mushroom? >> There's quite a lot of risky weird
2:17 mushrooms out there. So, yeah, if someone's selling you something in a brown packet, I would be cautious. >> One of the things that I've learned running a datadriven health company is this. Small actions create compounding impact. And you're hitting subscribe is one of those small actions. It tells the algorithm that this show matters. And that helps us to reach more people. and it lets us bring you more sciencebacked advice. So, if this episode gave you value, subscribing is how you can give a little back and we'll keep showing up every week to return the favor. Okay, back to the show. When I was young, mushrooms were definitely something I ate, but only because my mom liked the taste of mushrooms and she was cooking. And then more recently, I feel like I'm surrounded by claims that mushrooms can
3:03 extend your life, like improve your immune system, prevent brain aging, and so on. Now, look, I love the taste of mushrooms. So, any excuse to eat mushroom is good, but my son hates them. So, it's not really the taste, like the texture. So, my objective for this podcast is to come out with compelling arguments for why he should keep eating mushrooms even though he doesn't like them very much. >> Right. Okay. Mission in mind. Yeah, I can't change the sliminess, I think. But bad luck. >> You had this crazy answer that a mushroom is more closely related to me than it is to a plant. So, what is a mushroom? >> So, we now know pretty clearly that mushrooms and animals share a more recent common ancestor than plants do. So, if you think about that evolutionary
3:49 tree of life, plants branched off earlier than fungi generally and animals did. So, hence the answer, we're more closely related to a mushroom than to a plant. Not by much. I have to say that branching is still a very long time ago. But actually that explains quite a lot of things I think about mushrooms. So if you think you the most obvious thing is they're not green, right? They don't photosynthesize. Plants do. Um so that tells you already that they're probably not a plant. If you look sort of molecularly, there are quite a lot of other reasons why uh they are more similar to animals. So for example, some of the machinery that we use to make proteins in our cells. Fungi use a machinery that's more similar to ours than the machinery plants make. So there's quite a lot of reasons to be confident that we are more closely related to fungi. >> And so you just started to touch on it, but are there other differences between
4:35 fungi and plants? And so does that mean that somehow if I was eating a mushroom, there are therefore genuinely going to be things that I'm sort of eating that wouldn't be in a plant? >> Yeah, absolutely. Yeah. So perhaps the most obvious is that plants and fungi both have cell walls, which is why they're rigid, unlike animal cells. We're pretty floppy, but it's made of something completely different. So, so plants are made of cellulose. People might remember that from school. Fungal cell walls are made of a molecule called kitin, which is actually the same molecule that is in the shell of crustation. So lobsters or crabs or insects, they're the crunchy bit. If you step on a beast and it goes crunch, that is kitin. It's the same molecule in a fungal cell wall. So that's a that's a really obvious one. And then if you kind of really look biochemically, I mean one of the most amazing things about fungi
5:21 is they are incredibly chemically diverse. And so for instance, many of the antibiotics we get today are produced by fungi because they're able to do this fantastic chemistry in some cases chemistry that we haven't managed to crack as humans yet. So there are depending on the species, lots of molecules you find in fungi that are not found in in plants or in animals or sometimes even in other species, sometimes really unique. And so that means that if I was eating a mushroom, there could genuinely be like molecules in there that I just would never get even from eating lots of diverse plants. >> Yeah, absolutely. And they can be good, bad or indifferent. So there are some nutrients that come from mushrooms that are really important. But of course people familiar with the fact that some mushrooms, some toad stores are hugely poisonous, potentially lethal. And of course there are also magic mushrooms
6:07 that produce hallucinogenic compounds that are not found in other species. Now, I asked about mushrooms and you immediately switched out to fungi. I ran with it, but can you help me to understand what the difference is? >> Yeah, absolutely. So, we talk about the fungal kingdom. So, if you think about we're talking about plants and animals and fungi. So, each of those is a kingdom. It's a big group. And fungi as a kingdom, we don't really know how big that is. We estimate probably something like one and a half million species of which the vast majority are still not known to science. These are all closely related in the sense that they all share those characteristics like a kit and cell wall, but they are wildly different. So for instance, athletes foot on your foot is a fungus. The yeast that you put in to make your bread rise or your beer brew is a fungus. The mushroom you buy in your supermarket is
6:52 also a fungus. So fungus is the wider group. Mushroom sort of doesn't really have a kind of biologically defined term, but we tend to use it for the fruitting body. So if you think about what a mushroom looks like in a supermarket, if you see that growing in the field, that's actually a tiny fraction of the whole organism. Most of that organism is invisible underground in this kind of hairike network that's called a mcelium. And it's only when it fruits that that comes up. So I guess it's a little bit like thinking about, you know, we talk about an an apple, but the apple tree is, you know, much bigger than the apple alone. So the mushroom is the fruiting body of a particular species, and not all fungi produce mushrooms. So the yeast that you make bread with, you know, you don't come hopefully don't come down in the morning and find mushrooms popping out of your bread. Certainly not from that yeast anyway. It stays as a yeast its whole life. Other fungal species can move
7:40 between this yeast form and this kind of fruing form. Actually, the kind of scale of the invisible part of fungi is something people often overlook. So if you think about out in your garden or the woods, you know, you see a a toad stool pop up, often that toad stool is revealing the presence of a mine that's enormous. In fact, there's quite well doumented cases in the United States, for example, of individual fungi that stretch for miles underground. So, you see a mushroom pop up here and 5 miles down the road you see another mushroom pop up and it's actually fruing bodies of the same super organism that's under your soil, but we just can't see that bit. >> That's wild. So, you're saying there is just one fungi that can be like 5 miles long. >> Yeah. Biologists like to fight over kind of records and and if you're a kind of micologist or someone who specializes in fungi, you always claim that you have the biggest organism in the world
8:26 because if you were able to haul that out of the ground, it would be far larger than a blue whale or a giant redwood. Obviously, the problem is we can't actually extract it and show that. >> Now, I think all of our American listeners are saying, "Yeah, but of course everything's bigger in America." So, is it just in America that you get five mile fungi or if you were in Europe or Australia, whatever? I mean, is that also true? Yeah, I feel like we might be starting some kind of international competition here for large fungi. No. So, the largest one that we currently know of is in the United States. I don't think there's any reason to believe it would have to be in the United States. I suspect quite a lot of this is about who's going looking. You know, there are lots of really great micologists in the US who look at these things, but I'd wager you can find a bigger one in Brazil if you go looking. When I was young, like I only ever saw button mushrooms in the store. And now I
9:13 regularly see like oyster mushrooms and shiakei and lion's mane. And that obviously represents the fact that many more people are eating mushrooms and also like this sort of wilder diversity. What's been driving that shift in terms of just like what we're able to eat in the supermarket? >> Yeah, I think there's probably a couple of things that are playing there. So I mean obviously here in in Europe and the US we've been very restricted in our pallets for quite a long time. I mean that's not true in in the Far East for example. I I well remember many years ago traveling to Japan you know and having just extraordinary dishes with with mushrooms uh which I had never seen before and which people couldn't tell me the name of. So I think many cultures have a much more diverse repertoire already. Part of that change in in Europe and the US in recent years has
9:59 been that globalization of the food economy. people traveling eating stuff they like elsewhere and saying why can't I buy it here? Uh partly it's also about the ability to produce these. So producing um mushrooms or related fungi is quite different to other sorts of farming. Um and so uh it takes investment. It takes kind of skill and so you have to sort of have a market that's going to make it worthwhile. Um but of course as we know espec the more exotic fungi mushrooms often sell for quite a premium and so there's been quite a big market driver to support the development of those. And I think probably the last thing is that people have become sort of more experimental in their diets. Um people are very interested in healthier diets, more diverse diets, um cuisines from elsewhere. And so I think it's driving that overall kind of shift in in what we
10:45 buy and what we cook. I'm struck by your saying that when you first went to Japan, you suddenly saw that they ate all of these different mushrooms and you're an expert, but you're like, "Oh, I don't even know what this mushroom is." Is that because there just were many more varieties of mushrooms that you can eat, or is this just because somehow Western Europe and obviously, you know, places like America just were not really open-minded about it? >> Yeah, I think it's probably a bit of both. I think I so one of the characteristics of most most fungi like growing kind of damp humid conditions. I think there's something about uh the climate you're in. So if you take the UK for example, you know, middle of winter, you can't go and find mushrooms out in in the wild because it's too cold and there's just not enough uh environment for them. If you're in the tropics, you can find mushrooms toad stores all year
11:30 round. So there's something about availability historically, but I think there's also something about sort of cultural acceptability and particularly the kind of flavors. A lot of fungal species that we eat, especially the more unusual ones, have really quite marked flavors. And we know that people are usually quite reluctant to kind of experience new flavors initially and they have to kind of be um exposed to it. And so one of the things for example is that many fungal species have a very strong umami flavor. This sort of it's quite difficult to describe is this kind of rich kind of uh deep flavor that that polarizes people. Um I think that's a much more common flavor historically in Asian cuisine for example. And so people are ready to embrace this. I suspect in 1950s England, if you'd have come with a strong umami flavor, people might have, you know, run away. >> I'd love to now sort of almost drill
12:16 down to nutritionally speaking sort of what's in a mushroom. >> Well, it depends first of all on what we mean by mushroom. I think I mean clearly the one we know the best is the classical uh mushroom that you buy from, you know, the supermarkets, white or brown big cap on the top. It's an agaragus species and we know quite a lot about that. Mushrooms are often used to replace meat in sort of vegetarian type cuisine. Um, and it's a good replacement. So, they have more fiber definitely than animal products. Uh, not as much as some of the kind of really fibrous sort of whole grain foods. I wouldn't recommend substituting your granary bread or your oatmeal with fungi, but they they are quite healthy in terms of fiber. Good levels of protein, um, very low levels of fat, particularly saturated fat. So, that's all really promising. Uh but the thing that gets people quite broadly
13:02 excited I think about mushrooms is a lot of the more interesting kind of trace elements and vitamins. So if you think about the way that fungi grow, we talked earlier about this kind of you know myelium network in the soil. So they are scavengers essentially. They're harvesting nutrients from the soil from decaying matter. So they are really good at accumulating things that are quite rare or trace elements in nature. So for instance things like potassium they accumulate very well from soil. relatively rare compounds like selenium are also quite often accumulated by mushrooms. And then last of all, they're pretty good at making vitamins. Um, so they make vitamin B, vitamin C. Um, and the one that gets people really excited is vitamin D because vitamin D is extremely rare in plant species and we need relatively good levels of vitamin D particularly
13:47 for our immune systems. And so people often talk about uh mushrooms being a great source of vitamin D, although it is slightly more complicated than that. I asked at the beginning, is it true that mushrooms contain vitamin D? And I think we often think about that as something you get by being in the sun. What is the reality? >> Yeah. So, so you're right. So, we make it by being in the sun. Um, and just as a kind of caveat here, that does not mean going out and getting yourself lobster pink. That's a very bad thing to do. You don't actually need very much sunshine, even in rainy old Britain, but you do need a bit of sunshine to make vitamin D. Dietarily uh we get it from a variety of foods but but many foods do not have vitamin D and actually mushrooms are a great source. In the winter in particular it's quite difficult for people in northerly clims
14:33 like the UK um or northern US to make enough vitamin D. So that diet becomes really important. Um and mushrooms are often touted as a great way to get vitamin D because they they make vitamin D sometimes to very high levels. There are two caveats there though. first is that the amount of vitamin D they make is very very variable between species. Uh so for instance if you think about oyster mushrooms which you can now buy in most supermarkets they actually on average make about 100 times more vitamin D than your routine field mushroom that might be next to it in the shelves. So there's quite a big variety between mushrooms. >> And Robin, when you say routine field mushroom, this is like what I think of like like a little cap. And it doesn't matter whether it's white or brown. >> Yeah. button mushrooms, field mushrooms, the kind you might have on your English breakfast or mushrooms on toast or or
15:18 whatever that uh that one. So, so they they do produce vitamin D, but they produce less. >> And so you said oyster mushrooms create hundred times more vitamin D than like the typical mushroom that I grew up with and that I thought was the only mushroom probably when I was 15. >> Pretty much. Yeah, exactly. And that's very different species make more or less. But the big thing about all mushrooms pretty much is they are making vitamin D just like us in response to sunlight or actually in response to UV light. So if you have and of course if you if you think about the way mushrooms grow, they shouldn't see very much UV because most mushrooms grow in the dark. So if you grow your mushrooms in a industrial farm in the dark, harvest, stick them on a supermarket shelf and someone comes 5 minutes later and buys them, they'll have almost no vitamin D in them because they won't have seen much sunshine. Uh but the longer they see UV light for,
16:05 the more vitamin D they make. Uh and so you might be able to, you know, you might have seen in shops vitamin D enriched mushrooms which are essentially mushrooms that have been left in the sunshine for a little bit of time. You can do the same trick actually at home because they will produce that that reaction to create vitamin D uh is a spontaneous chemical reaction. So what's happening is a molecule in the membrane of the fungus called agoststerol is being converted by UV into vitamin D essentially. So you don't need the mushroom to be growing to make vitamin D. So actually laying out your mushrooms in a bit of sunshine where it'll get UV. So not inside a glass thing because glass filters out UV, but outside on your picnic table or whatever, they'll start producing vitamin D. And actually an hour or two of sunshine is enough to raise the level of vitamin D in in
16:51 mushrooms very dramatically to the point at which a kind of decent serving of mushrooms, eight or nine mushrooms, will give you your daily requirement. I guess a bit like fruit that continues to ripen and the bananas that I'm used to. You're saying if I put that out in the sunshine for like literally one to two hours, suddenly it creates this like rather amazing amount of vitamin D cuz you then said, "Well, then eat eight to nine mushrooms and I've had my daily amount." >> And if I think about other vitamins, I'm always struck that often they, you know, they claim it's on the pack, but you have to eat an awful lot to actually get the amount that is recommended. >> Yeah. Yeah. Exactly. So, and it's obviously there's a there's a variable art here, not least because mushrooms vary in size. Um, but you know, as a very ballpark sort of estimate, uh, you
17:37 know, 50 to 100 grams of mushrooms that have been in the sunshine for an hour or two will give you plenty of vitamin D for a day. >> Now, you mentioned before that different mushrooms are very different in the amount of vitamin D. So, is it all about the oyster mushroom now? >> Uh, no, not necessarily. So, as you can imagine, not that many mushrooms have been studied. Um there was an interesting study a few years ago looking at the quantity of vitamin D in in various commercial mushrooms. I think the winner actually was the bolit uh which is a kind of slightly exotic fancy mushroom that not many people have eaten. So um harder to buy that one from your supermarket but if you get the chance they have I think that's 500 times as much as your typical button or field mushroom. Um and then oyster mushroom and then you have you know the kind of more routine mushrooms have a bit less. I mean pretty much all
18:22 mushrooms do make some vitamin D. So this is, you know, so I wouldn't kind of run away and not eat a mushroom anymore, but it's just worth bearing in mind, especially if you have the opportunity, you know, whilst you're cooking, put your mushroom pot outside for half an hour and then throw it in your omelette and you'll do yourself some good. >> And so are the other ones all roughly similar to the button mushroom or is it particularly bad? I'm just curious. >> No, it's not particularly bad. Um, there yeah, there are several with that those kind of levels and actually there's quite a lot of variability there. So one of the things that's slightly frustrating for us scientists is the structure of the mushroom seems to make quite a difference. So you have more of the molecule that turns into vitamin D in some parts of the mushroom. So whether it's kind of flat or open or button makes quite a big difference. Generally speaking, there seems to be more gusterol and therefore more vitamin D made in the gills. So in the kind of
19:08 fluffy bit under the mushroom um than elsewhere, but I mean I wouldn't, you know, I wouldn't take the effort to turn all your mushrooms upside down to make it work perfectly. >> And for those of us living in cold northerly climates, is this going to work or is this a great trick? But it only really works in Florida and frankly they don't need to worry about the mushrooms because it's sunny. >> Um, so you need the UV to make the conversion work, but actually even winter sunshine has a reasonable amount of UV. So if you think about, you know, one of those gloriously winter crisp days in Boston, for instance, uh, you know, putting your mushrooms out will be fine actually will do quite a good job there. Um, and I think the other point is that this is not your, for most of us, this is not your sole source of vitamin D. So for example, things like cow's milk also have vitamin D. So if you're, you know, having milk on your breakfast and and a mushroom, you know, you're still doing pretty well. Uh so so
19:55 yeah, I wouldn't worry too much about that. I mean, clearly if you leave live in sort of northern Sweden, uh and you've got 23 hours of darkness, it's not going to be such a great trick for you in the winter. Um you might want to think about vitamin D supplements instead then. >> Brilliant. Well, I'm definitely now pushing oyster mushrooms right up in my head as I'm I'm thinking about this. While we're talking about vitamins, the team who were doing the research here said that there's a compound that I have never heard of before that I have to make sure I ask you about which is called ergoionine. >> Very good. Yeah. >> What is that and why is it that some scientists are apparently saying it should potentially be classified as a vitamin? >> Or so ergoine is a very interesting molecule. Um it's a natural amino acid. So people might be familiar with the
20:40 idea that amino acids are the building blocks of proteins. Um we as humans make about 20 or use about 20 amino acids to build our proteins. But there are other amino acids that we don't make we don't use that are used in other organisms and ergoanine is is one of those. So it's made by uh fungi in particular and in laboratory studies it has quite potent antioxidant and anti-inflammatory effects. So antioxidant people might be familiar with this idea of reactive oxygen species. So we're familiar with oxygen that we're breathing now. There is a chemically related molecule which is a kind of charged reactive breakdown product of oxygen that damages things. It damages proteins. It damages DNA. Um and uh it is thought that reactive
21:26 oxygen account for quite a lot of cellular damage as we age in particular. um was one of the reasons for instance why you know if you spend a lot of time in sunshine you get older looking skin because the reactive oxygen that's created is damaging your cells. So reactive oxygen not great. Uh ways to mop up and dispose of reactive oxygen are therefore thought to be beneficial in protecting us from damage and and helping delay aging. And ergoine is a really good molecule at mopping up oxidative damaging agents. So in a lab absolutely this soaks up reactive oxygen. So that seems like something you might want in your cells. Uh and so there has been quite a big kind of interest in whether eating loads of mushrooms will give you lots ofine and that will help protect you. Have to say the data on this is very much still up for debate. So you know if people are
22:12 listening to this I wouldn't race out and order yourself massive supplements. We're still a long way off being sure. What we do know is that in some situations it does seem to have some potential beneficial effects. There have been some studies looking at cellular hallmarks of aging and if you're exposed to ogionine it seems to reduce that. Um no really good clinical data suggesting broader health impacts a minute but as with all science you know there's a lot more to do in this space. Uh one of the really big mysteries I think toine is we humans have a specific protein that is used to take ergothine into our cells. um it's very conserved so other species have this too and that sort of suggests that it must do something really quite important because evolution has kept it and looked after it. However, our kind
22:59 of typical way of testing these things is to remove it genetically uh from mice for example for those mice seem pretty fine actually. So there's a bit of an enigma here that we have this protein that appears to have been conserved does something important but we don't know what the important thing is. And perhaps the last and most weird unexplained thing is that that version of uh that protein that takes up ergothane varies between different humans. So different populations have what's called polymorphisms, variation of this. We don't really know um what that means or why that's important. But there has been quite a lot of renewed interest in that because it looks like one particular variant of this is associated I stress associated rather than causitive but associated with Crohn's disease. uh and so if you carry that particular type of
23:45 receptor, you appear to be more at risk of Crohn's disease. We don't know why and it may be complete, you know, red herring correlation, but yeah, a lot of interest in egoine. So, this is one of these examples where we're getting access to like this very early scientific uh insight, but you're not suggesting that we all have to go out and make sure that we're getting enough ergoion from our our mushrooms and we're all going to live another 5 years of healthy life. >> Yeah. I mean, it's kind of like the scientific equivalent of that moment when you've finished your flatp pack furniture and you've got this thing left over and you think, "This looks like it does something really important, but I don't know where it goes." And so, we're at that we're at that point, I would say. >> Do all mushrooms have like high levels of this ergoion or is this only in particular mushrooms? >> So, not all mushrooms produce ergoion,
24:31 but it is relatively widespread. So, it's very rare in other branches of life. So, plants don't make it, animals don't make it. um the places it's made naturally are quite a lot of fungal species and in the cyanobacteria. So these photosynthetic bacteria um that are associated with things like algal blooms and the sea, but obviously we don't eat those. So mushrooms are your best bet. Levels vary in different mushrooms. Um and we don't really know how they vary in different species. We also don't actually know what a what a sensible level would be. So although that has neuroprotective effects, you know, because we don't know what it does, we don't know whether you think such a thing as too much of it or too little. So, >> so if I was having like a standard like butter mushroom, is there likely to be some ergoionine in it? >> Yeah, there is. Your standard mushrooms have some um levels vary. Uh and again,
25:17 we don't really know what a good level is. So, uh I mean, no evidence of harm. That's always a positive thing. Uh but I think we're we're definitely far from saying this is some kind of magical cure all. >> And so, we talked about vitamin D. We talked about this ergoionine. Um you mentioned at the beginning that there's quite a lot of fiber in these mushrooms. Are there any other nutrients that are like helpful for us that are in mushrooms? >> Uh yes. So most mushrooms produce vitamin B and vitamin C. Um and they also I think we mentioned earlier they harvest these kind of minerals like potassium and selenium. Um uh and they do quite a good job of that actually. So so generally there's quite a lot of kind of trace elements or minerals that are in that are in mushrooms is good for you. I'd love to talk now about some of
26:04 the health claims that surround mushrooms. So, less about the nutrients and more like what does it actually mean for us as human beings. And I know talking to friends of mine from like China and Japan that apparently they've been like an important part of their sort of traditional medicine apparently for thousands of years. But I'd really like to know what the the science says. Is there any evidence that suggesting eating mushrooms is linked to either healthier lives or or longer lives? >> Let's focus first of all on kind of your classical supermarket mushroom. Um uh and the short answer is no, not really. So there have been a couple of studies looking at these very large population studies looking at diet and longevity. Couple of caveats. One is they're usually done by what's called recall
26:49 studies. So people say, "Jonathan, what did you eat last Tuesday?" you know, and I don't know about you, but often I think I don't know what I ate last Tuesday. So, there's a lot of patchiness in the data as part of a broad varied diet that doesn't have too much red meat, etc., etc., they do have a significant benefit. So, for example, even if the mushroom on its own is not particularly dramatic, if you're replacing your fillet steak with a, you know, mushroom, then actually that will have a benefit because we know that too much red meat is bad for you. Okay. So, there's a there's a thing about eating mushrooms as part of a varied diet that's good, but as a kind of magical food to to make you live forever. Unlikely, I think. >> So, is it just that the data isn't there and you think it is beneficial for health or do you think that it's like a good thing like lots of different plants are, but you know, even if we did a great experiment, you're not going to
27:34 see any impact. >> I think the data is a real challenge for a couple of reasons. So one is that we talk about mushrooms in inverted commas but you know that's a bit like talking about plants you know and if I say to you you know you does eating plants correlate with long life well yes it definitely does because if you don't eat any plants you're not going to live very long. Um so I think there's a big problem there that we talk about kind of you know mushrooms generally and we're not able to distill in to individual levels of detail. Secondly of course it's actually pretty recent. I mean in some cultures people have been eating mushrooms for a long time. in most western European US uh cultures it's it's a very small number of species for a very short period of time and those those are the areas of course where most of these long studies have been done so you so the data is not just the data is not there but the experience of people is not there to draw on that might
28:21 change going forwards now that people eat more species there is the potential to really look in more detail particularly in other cultures where you know a broader diversity of of fungi have been eaten for a longer period of time and maybe we'll see something interesting One of the big things I hear is about brain aging. Is there any evidence around this or any reason to think even that it might matter? >> You know, one of the points about fungi is that this is a huge diverse group of organisms, right? One and a half million species and they are amazing chemists. So they can produce just wild molecules and you know perhaps the best example is you know antibiotics right penicellin is a fungal product. I mean now we make it synthetically but uh but it was a fungal product and so they can make incredibly impressive chemicals. So you know at face value might mushrooms in inverted
29:08 commas help us live forever? Absolutely. Because somewhere out there there might be a species making something really important. If we're thinking about kind of the small number that we eat at the moment as part of regular diets, there's been quite a lot of interest in whether particular species might help protect your brain. uh and lion's mane is the one that's often quoted as a kind of you know lion's mane fungus uh live forever. Um and there is a little bit of data suggesting that that it's worth at least looking at this in more detail. So for example, some extracts of of lion's man and actually some other species seem to in a laboratory setting in a dish stimulate nerve growth. Um and so that you know at face value you might say well creating a few more neurons if you're especially if you're losing
29:53 neurons due to you know dementia or something else might not be a bad thing. So there's a kind of plausible biological mechanism in terms of kind of studies in people the jury is very much out. So there have been some studies uh demonstrating slight improvement or or a a slowing in reduction of brain capability in people with early mild cognitive decline. um small studies uh not highly replicated yet. So you know be cautious but perhaps slightly promising. Uh there was one interesting study that people often talk about uh a lot on social media where people without any cognitive decline relatively young people showed an improvement in their mental score on a kind of classical test uh which actually is a test where very it's very rare to see things that
30:40 improve that score in people who don't have cognitive decline. So you might see online people say w your IQ will go up if you eat this uh you know which is often based on those kind of studies um again very very small very limited there has been at least one study which has shown the opposite which has shown if you have it your your ability to recall words drops um and so like much much of science I think we are still a long way from a kind of solid answer >> and so when you look at all of that you know I think a lot of what you're taught right is to discern the different quality of evidence across these studies. What's your guess about mushrooms and their ability to have any impact here? >> Yeah, I think I would happily wager a mortgage payment on the fact that
31:25 somewhere out there in the fungal kingdom there will be, you know, fungal products that are going to be massively beneficial for medicine and therefore long longevity. And I wouldn't rule out the possibility that, you know, in the future there will be particular species or particular extracts that will be recommended for everybody to take. If you enjoy it, it fits in with your lifestyle, there's no evidence of harm. Uh, but I definitely wouldn't, you know, go out of your way to take a particular mushroom supplement in the hope that it will help you live forever. >> I'd like to share my favorite healthy habit with you. It's called Daily 30. Daily 30 is our gut supplement made with over 30 plants individually selected by our science team here at Zoey. In just one scoop, you get ingredients that support gut health, digestion, energy,
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33:45 normal function of the immune system. Daily 30 is also high in fiber, omega-3s, and plant protein. Ready to feel better? Start Daily 30 today. Head to zoey.com/aily3030. The other, I think, big area that I read a lot of claims is around immune health and inflammation. Like, we've seen more and more of this overlap between that and and the microbiome. And so I think most of our listeners are sort of aware that long-term inflammation is not something you want to have, but we all have this like high level of long-term inflammation living in the western world compared to to the past. Is there any evidence that eating mushrooms can have any beneficial impact there? >> Uh so I think it's really important to think about again about this kind of breadth of the fungal kingdom here and
34:31 you know because I spent quite a lot of my life working on on fungal diseases that kill people. But I do want to kind of emphasize the fact there is a spectrum here, right? There are fungal species that are probably very good for us and we eat, there are fungal species that you know you really don't want to get. >> This is your I have athletes foot, but even though it is a fungus, it's not a good thing. I was thinking >> athletes were definitely not great. Although that's more in the annoyance, but there are, you know, a handful of fungal species that are potentially fatal. Um, particularly for people who have weakened immune system. So I think really important to stress here that, you know, if you are thinking about how can I prop up my immune system because it's already impaired. I've got a genetic disorder or I've got HIV positive or something. Uh, you know, dietarily absolutely fine, but but you know, if you read someone's magical thing about sniffing a fungal spore, just don't do that. But that
35:17 notwithstanding, I think one of the interesting things about fungi generally is that many of the molecules that are present in fungus, particularly on the surface, do have quite potent immune effects in in humans and other animals. That's largely, I have to say, because the immune system has evolved to react to and get rid of fungi. It's not a good thing to have fungi growing in your lungs. For instance, if you think about that cell wall of the fungus, most fungal species have a molecule called betaglucan inside that fungal cell wall. Um, that's a really potent immune stimulus. So, if you put betaglucan into somebody, their immune system lights up because it's trained to say, "Here's something I should react to and get rid of it." And in fact, we use betaglucan as what's called an adgivant to to help some vaccines really generate a good
36:03 immune response. And so there is there definitely immune effects in fungi. Less clear is the kind of ability of the immune system of fungi to suppress the immune system. So there are specific examples particularly in some pathogenic fungi of molecules that the fungi use to deliberately suppress the human immune system, but that's for their own advantage, right? That's because they want to grow. Um, and so I definitely wouldn't recommend people expose themselves to those two. Unclear at the moment whether similar molecules in fungi that are not harmful might be beneficial. Um, so so yeah, sort of jury still out. Probably the last thing to say on that though is there's also a sort of secondary effect in that fungal products are really important for influencing the microbiome of the gut. So for example, many of the uh sugars
36:50 and the carbohydrates that fungi make are really good kind of food stuffs for the bacteria in your gut. And so there has been quite a bit of evidence that some mushroom species will help stimulate a kind of good microbiome for one of a better word. And of course the good microbiome can have a very strong positive effect on your immune system. So, it's interesting. You're wrapping up on a topic that obviously we love on this this show and you're saying that perhaps one of the most valuable things that these mushrooms are doing is actually to be food for our gut microbes and they might then be producing these compounds that are beneficial for us. >> Exactly. Exactly. >> This is a lot like a plant where again there's lots of things here that I can't digest directly and so if I want to get the benefit I need to get the the micros to sort of break it down for me.
37:35 >> Yeah. Exactly. So there's, you know, and we we often sort of overlook, I think, the fact that your your microbiome is just this wildly complicated ecosystem. And if you think about the relationship, bacteria and fungal species have been evolving together for, you know, obviously far far longer than we have. And so uh there are some really quite complicated signals. So if you look for instance out in in soil, you know, there are really well doumented situations when a bacteria might make a molecule, the fungus picks it up and behaves differently, it produces a different molecule, the bacteria changes its behavior. There's a complicated conversation going on. Uh we're only just starting to scratch the surface of that, but very reasonable, I think, to think that when you eat a mushroom, you're probably plugging into that evolutionary conserved kind of communication system and having an impact on the on the bacteria that live in your gut. Are there any funguses that
38:23 should be growing in my gut or is it now clear that like bacteria are great, but that's again one of these big distinctions. we don't want any of these fungi and therefore our immune system does not play nicely with them. M uh that's a really good and very very live kind of topic in you know if you go into social media lots of people with strong views there historically you're right so people have historically sort of said fungi growing in your gut bad thing and and in some circumstances that is definitely true like most things about the gut microbiome you don't want dominance of a particular species for instance that said it's really only in recent years that we've started to understand a bit more about what appears to be the kind of natural fungal microbiome of the gut and that's largely speaking because they are massively outnumbered by the bacteria. So early
39:09 genetic sequencing, you know, you just take your abundant DNA and it's only with the advent of technologies which allow us to look at very rare, very low levels DNA that we start to see these fungal species. Um, and I think kind of an emerging view that there are definitely some species that are probably quite good to have in your gut. Uh, still very unclear which ones those are and what they they might make the difference for them. But I think that sort of realization that fungi are kind of everywhere and are part of your natural microbiome very important and in fact uh you know outside of the gut. So skin for example you know we're covered in interesting fungi um that do all sorts of weird wonderful things. My favorite example being someone called malisthesia that grows only really on the human head and in fact is only able to reproduce in the presence of human sweat excretions. So there you go. >> You're now kidding me. >> Nope. There is a fabulous uh
39:55 demonstration that this particular fungus is completely required. I have a colleague who says it's a creepy feeling to think that there's a endangered species that can only have sex on your head. >> There is a fungus that can only grow on the human head and cannot reproduce unless it gets the particular like sweat that comes off from the human head. >> Yeah, it's the oils that you produce in your head that seem to be a signal for it to to sporate to produce reproductive uh organs. >> That's fascinating. This is this example of how we are this ecosystem with these tiny microbes and that includes fungi. We talked about bacteria a lot. You're saying there's fungi that absolutely only coexist with us. >> Yeah. >> You know, you might think that's just a parasite, but is your view that on the
40:41 skin some of these fungi are actually beneficial to us? >> Yeah, absolutely. And in two different ways. So there are probably some species that are genuine sort of symbiants. So they're there, they never do any harm and they're kind of good for for uh you know whatever reason they might be helping to sort of digest things you don't want or they might be kind of helping to regulate the immune system but also there are there are species that are sort of at face value potentially bad news but their presence helps with this kind of maintaining a normal immune system. So one that's often talked about is candida um and there's a sort of whole uh world out there of kind of candida syndrome and candida things and people so candida is absolutely a fungal pathogen that can cause serious disease. It can cause, you know, vaginal thrush, oral thrush, sometimes systemic lethal fungal infections, but all of us have candida
41:28 all the time. If I'm going to go and swap my armpit, you'd find candida there. And that's not a bad thing. It's there. It's kept in check by the immune system, and it's probably helping to keep our immune system in balance. So, you know, as with many of these things, you don't actually want to be a sterile site. It's good to have a a healthy microbiome, even if it includes things that can on occasion go bad. >> Absolutely fascinating. I also heard that mushrooms might have a cholesterol-lowering compound. Is that true? >> That is true. Um, so they produce in their cell wall this molecule that we mentioned earlier, betaglucan. So the ma the main structural component of the cell wall is is kitin. I think that's in lobsters and beetles and things. Um, but they also have this layer called betaglucan. And betaglucan is a uh it's a it's a polymer. So it's a chain of sugar molecules, glucose molecules. We
42:15 talk about beta glucan but actually this is a whole family of molecules because if you think about joining your sugar molecules together you can put branches on them you can do different things so the structures are all quite different. However, um what appears to be pretty clear now is that when we eat betaglucan, it can kind of form a a sort of gel in our in our guts. And that gel is actually very effective at absorbing cholesterol, keeping it away from your cells, especially LDL, so the kind of bad cholesterol um and then essentially getting pooped out the other end without you taking up too much. So, this is the same group of molecules that is what makes oats really good for you. So, our, you know, recommendation to eat oats, oats are great at helping to lower cholesterol. uh fungi produce less betaglucan than you have in oats, but nonetheless quite a significant amount.
43:01 So, if you're already having oat porridge, uh great. I wouldn't swap that out for a mushroom in the morning, but if you're taking mushrooms additionally, it's another good way to help lower cholesterol. I would like to talk about actionable advice about like how can I actually add mushrooms successfully into my diet? Could we talk about the cooking for a minute? Cuz I always feel that when I cook mushrooms, it feels like the darn things basically disappear, right? It's really big. You cook on some heat and it just like shrinks and shrinks. And so I've always sort of felt, well, I've probably killed everything that is of any value cuz it all shrunk away. Is this right? >> Not necessarily. So, um, heat does remove particularly vitamins. Uh, you know, levels of vitamins drop quite dramatically when you heat, especially for for long periods of time. Um, having
43:46 said that, of course, depending on what you're doing with your mushroom, you might not be heating for very long. If you're kind of frying a mushroom, you think about those big fat delicious field mushrooms. You know, you might give it a minute on one side and 30 seconds on the other and you're done. So actually in that sense, you're retaining kind of more vitamin than if you're going to put in the oven for an hour. Probably the bigger risk with boiling is the water solubility. So a lot of these things that are in mushrooms are highly water soluble. So vitamins B and C, but also things like potassium um are very water soluble. So, if you're going to boil your mushrooms and then just throw away everything they were boiled in, that is leeching out quite a lot of your nutrients. If clearly if you're boiling it in a pasta sauce and you're going to eat your pasta sauce, not a problem. You've just moved your potassium from inside the mushroom to outside. >> A bit like I think how I was brought up to do carrots, you know, if you're putting a great big pot of water and then you throw away the water. It's like
44:32 literally you're throwing away >> the good stuff. >> The good stuff. >> Yeah. Exactly. I mean, my my usual, you know, best rule is the best way to cook something is the way that you're going to eat it. uh you know so if you're if you're someone who uh you know will only eat a mushroom if it's been cooked for a long time then that's fine because the alternative is not to eat at all. What about preparing the mushrooms? One of the thing I'm always struck by is a mushroom comes it always feels like it has like dirt and mud on it. I always feel like well I got to like sort of scrub the dirt off it also puts me off a bit eating it. >> You know back in the old days you say oh you should peel your mushrooms. Um, actually, you know, that's a relatively, if you're worried about the dirt component, there's a relatively limited value in peeling because, as we know, the bottom bit doesn't have a skin on to peel anyway and the stalk doesn't and so on. So, you're still, you know, you're not removing that much dirt. So, I wouldn't worry about peeling. For sort
45:17 of aesthetic and general kind of taste reasons, it's a good idea to give them a polish off or a wash off and get rid of, you know, any soil that's left on them. The world of raw mushrooms I think is one that we got to be slightly cautious about because like any raw food there will be other organisms present there bacteria viruses whatever and so they are potentially a risk because of the way mushrooms grow and the fact they're quite difficult to clean well that is potentially slightly higher than with other foods. Um, so if you think about, you know, an apple for instance, you know, it's relatively easy to clean the surface of an apple in a way that you can't do with a mushroom. If you're picking a mushroom straight from the field, uh, you know, you've got no control over what's on that mushroom. Um, and so, as with all foods, the risk of, you know, potential food poisoning is is higher. You know, I might caution
46:03 against eating that one raw. The last thing to say is there are some compounds in many fungal species, including fungi that we eat, uh, which can be slightly harmful. Um I I want to kind of caution here but there's a kind of level thing but there are molecules called hydroines for example that in laboratory studies appear to be damaging for DNA. They're potential carens cancer causes. They're at pretty low levels. So this is definitely not a reason to not eat mushrooms. But they are also broken down rapidly by heating. So So if you're someone who's really wild at mushrooms and eats a lot of mushrooms, eating a really large level of mushrooms raw is maybe not a great idea. And I might be tempted to cook them a bit more. partly for the food poisoning reason and partly for this uh kind of question of residual damaging agents.
46:49 >> My take away from this is I probably don't need to worry about the dirt as much if I'm going to cook it and so I can probably be a bit more relaxed and not let my OCD loose on the on the mushroom. >> Yeah, I think if you can get over the psychological barrier of eating a bit of sterilized horse manure with your with your pasta sauce, you're fine. >> Would have been easier if you hadn't put it that way. What about how to cook mushrooms in a way that actually just like maximizes the pleasure and taste? It's very difficult to eat something that's good for you but you really dislike. So I would encourage people to kind of go out and and try different mushrooms um because there's lots out there um and they're all very variable. Loads of people I think like you said your your son and my son also
47:35 really dislike mushrooms when they're young because of the kind of slimy texture. Quite a lot of people actually get over that when they're adults, but they often don't know. So, I think if you're listening to this and you're an adult, you think, "Well, I don't like mushrooms, but I haven't tried them for 10 years. Give it another whirl because maybe maybe they're not as bad as you remember." This is a hugely diverse kingdom. So, we have to think about this not as mushrooms, but as vegetables in the same way that you know a corette is not the same as a sweet corn. Um, and so I think kind of testing different ways, use them in different kind of settings is a is a really good thing to do. Think about the way of cooking it. Some mushrooms become much more edible, you know, when you fry them. Some become quite tough and stringy. Some are great when they're ground and powdered. Some just taste like dust. Um, and so there's a sort of sense of the diversity of mushrooms out there and also the the
48:20 kind of way you're preparing them. And and last thing I think is think about the kind of meal you're using them in and the strength of uh, you know, experience. So I I you know, I think there are a lot of people out there, for example, who've had a very bad experience with truffles uh because they get this thing that looks absolutely tiny. you think, "Oh, I'll chop that up and throw the whole thing in." And then they realize that, you know, they're tasting truffle for a week afterwards. Um, these are really potent species, some of them. So, uh, so go steady, try it as you go. A bit like, think of them maybe as a bit more like spices than than, uh, you know, kind of a core component. If you're thinking about these more unusual ones and and test the flavors first before you put the whole family off, there's a diversity that we just don't appreciate because they're relatively new. The diversity of them is relatively new to the Western diet, I think. So, we're still like, well, what is this weird looking thing and how do we cook it? >> And if someone's listening to this and
49:06 saying, I want to add some more mushrooms to my diet. I'd like to maximize the potential benefit from doing that. So, yes, I'm only going to eat it if it tastes nice because like obviously I'm not going to stick with it otherwise. What would you be saying about the specific types of mushrooms that they should be trying to add? >> The single easiest thing to do is a few fried mushrooms. So, it's quite easy to add them as a sort of supplement side to things you're eating. If you don't like mushrooms or someone in your family doesn't like mushrooms, uh, you know, I think like with many foods, you can get around that by sort of small than invisible incorporation. So, I think there's there's many a child who avows a hatred of mushrooms, but if you chop them really fine and put them in the pasta sauce, you know, they won't particularly notice. These days, you can quite often buy from sort of supermarkets these kind of mixed boxes
49:53 of different mushrooms. If you're someone out there who's only ever had the classic or kind of white butter and mushroom, you're like, I wonder, you can pick up a kind of mixed box uh from mainstream supermarkets and give it a whirl, you know, an oyster mushroom or, you know, some of these kind of slightly more exotic ones, that might open your eyes a bit more and, you know, and then if you really get into it, you can discover a whole world of interesting pigs ear truffles growing on elder plants and all sorts out there. And is one of the takeaways from this that just like when we think about plants, one of the biggest things that um we talk about is like trying to get this diversity of plants because they're feeding all of these different microbes. Should I simply be thinking about this as I really want to get a diversity of mushrooms into my diet rather than there's just like one mushroom which is the best mushroom and so I should just make sure I'm only eating that one.
50:40 >> We don't have the data on that uh yet obviously in the same way that we do for plants. Um uh but you know I'd be pretty confident in suggesting that diverse mushrooms is probably better than a lot of a single one. And actually you know that's kind of good rule for life. Like binging on a single thing is generally not advisable. So even if you love mushrooms you know I wouldn't eat a kilo a day. Um uh so think about that kind of diversity. Um particularly when we're thinking about the impact on the microbiome. You know the microbiome loves diversity. So, different fungal substrates for your microbiome to grow on is probably going to be beneficial. >> Given all of this, Robin, do you eat mushrooms? And if so, what do you eat? >> Uh, I do eat mushrooms. I I love mushrooms. And actually, I mean, like many people, I'm sure, listening to this, mostly it's your traditional kind
51:25 of field mushroom type thing. Um, but you know, if I get the chance, I do like a oyster mushroom in particular, the occasional truffle. You know, if I'm eating a mushroom, my kind of favorite way is is fairly sort of straightforward. So, you know, he mushrooms next to an English breakfast. Great. Uh, one of my go-to recipes as a student back in the day, actually, was, you know, these really big fat field mushrooms that are usually quite expensive, but, you know, top tip, last thing on a Sunday at a supermarket, they're usually selling them off cheap because they're going to be horrible tomorrow. And you can stick some bread crumbs and some lemon on that and a bit of cheese on the top. Stick it under the grill. Great. And relative and the cheese is not so great for you, but everything else in there is pretty good for you. >> Amazing. I'm getting hungry. Just think about it. Finally, if you were going to give one tip for someone listening for
52:10 how to add more mushrooms to their diet like next week, you've given us many tips, but what would be your your one tip? >> Uh, can I do a tip and an anti tip? So, so my anti tip is please don't do this by going out and thinking that thing looks like a mushroom on my lawn. I'm going to pick that. That's a very bad idea. Uh, do go to a supermarket or reputable retailer first. That's my anti tip. Um, my top tip I think I would probably be to just think about mushrooms a bit more like we think about vegetables rather than this kind of special thing. So if you're thinking I'm going to do chicken fillet tonight, you know, uh, I'm going to do some carrots. What else should I do with it? Think about a mushroom rather than a frozen pea or maybe as well as a frozen pee. Um, uh, think about mushrooms as a kind of vegetable component that you can put into pasta sauces or things rather than this special thing that you have to somehow put your mushroom cook hat on to
52:57 deal with. >> I love it. Robin, I'm gonna try and do a a little summary and just correct me where I I get anything wrong. So, the thing that's sticking with me most of all is that there's a fungus that can only grow on the human head. And ever since you pointed that out, I've been thinking about this while looking at your head. And it shows how we like coexist with fungi at this incredibly
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