Cholesterol Lowering Properties of Beta Glucan

Welcome to Zoe Science and Nutrition, where world leading scientists explain how their research can improve your health S spent decades as one of the most boring ingredients on your plate Today, they have a reputation as one of the most exciting brain protection. Got health immune support Even longevardity. Health clas associated with mushrooms are astounding. We discover something new Were we missing something that was obvious all along all this excitement is simply unjustified In today's episod We're jin by Professor Robin May a microbiologist, scientific advisor to the UK goovernment and world leading expert on the way that mushrooms interact with our immune system Robin will help us understand which health claims are real and which are exaggerated whichich mushrooms you should be eating? how to prepare them to get the benefits Robin, thank you so much for joining me today. Nice to be here So we have a tradition here at Zoe, which is very hard for professors where we ask a quick fire round of questions and we say you have to give us a yes. or no or if you have to or one sentence You want to give it a go? I'macing ready. All right Are mushrooms more closely related to humans than to plants Yes ood eating mushrooms help you live longer Can have a moabbe? Yeah, you can Does some mushrooms contain vitamin D? Yes And finally, what's the biggest myth that you often hear about mushrooms The weirdder the mushroom the better it is for you. caaution against that one Not true. No, stick to the mainstream, I'd say Is that only because you might die by eating the weird mushrooms? There' quite a lot of risky weird mushrooms out there. so yeah, if someone's selling you something in a brown packet I would be cautious When I was young, mushrooms were definitely something I ate, but only because my mum liked the taste of mushrooms when she was cooking. And then more recently, I feel like I'm surrounded by claims that mushrooms can 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 h them So it's not really the tastes 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 Okay, mission in mind. yeep, 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 know pretty clearly that mushrooms and animals share a more recent common ancestor than plants do. So if you think about that evolutionary 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 branchingll a very long time ago. But actually that explains quite a lot of things, I think about mushrooms. So if you think the most obvious thing is they're not green, right? They don't photynthesize. plants do. 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 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 as a fungi. And so you just started to touch on it, but are there other differences between 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 wouldn't 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 plants are made of cellulose. People might remember that from school. Fungal cell walls are made of a molecule called chitin, which is actually the same molecule that is in the shell of crustaceans. so lobsters or crabs or insects the crunchy bit, if you step on a beach and goes crunch, that is chitin. it's the same molecule in a fungal cell wall. So 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 is they are incredibly chemically diverse. And so for instance, many of the antibiotics we get today are produced by fungi because they are 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 plants or in animals or sometimes even 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 are familiar with the fact that some mushrooms, some toadstalls are hugely poisonous potentially lethal and of course there are also magic mushrooms 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 talkking about plants and animals and fungis, so each of those is a kingdom is 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 kite and cell wall, but they are wildly different. So for instance, athlete's 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 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 fruiting bodies. 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 hair like network that's called a mycelium. And it's only when it fruits that comes up. So I guess it's a little bit like thinking about, you know we talk about an apple, but the apple tree is 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 made bread with, you know don' 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 between this yeast form and this kind of fruiting form. Actually the kind of scale of the invisible part of fungi is something people often overlook. So if you think about in your garden or the woods, you know, you see a toadstall pop up Often that toastal is revealing the presence of a mitenine that's enormous. And in fact, there's quite well documented cases in the United States, for example, of individual fungi that stretch for miles underground. So you see a mushroom pop up here and five miles down the road, you see another mushroom pop up, and it's actually fruiting bodies of the same superorganism that' under your soil. we can't see that That's wild. So you're saying that there's just one fungi that can be like five miles long Biologists like to fight over kind of records. and if you're a kind of mycologist or someone who specializes in fungi, you always claim that you have the biggest organism in the world 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 our American listeners are say, 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 or 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 mycologists in the US who look at these things, but I'd wager you can find a biger one in Brazil if you go looking When I was young, I only ever saw button mushrooms in the store And now I regularly see like oyster mushrooms and Chiitakei and lions's Me 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 Europe and the US, we've been very restricted in our pallets for quite a long time. I mean, that's not true in the Far East, for example. I well remember many years ago traveling to Japan and having just extraordinary dishes with mushrooms, 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 Europe and the US in recent years has been that globalisation of the food economy. peopleeople traveling, eating stuff they like elsehere and saying why can't I buy it here A partartly, it's also about the ability to produce these. so producing Mushrooms or related fungis is quite different to other sorts of farming. and so 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. But of course, as we know, 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 become sort of more experimental in their diets. People are very interested in healthier diets, more diverse diets, cuisines from elsewhere. and so I think it's driving that overall kind of shift in what we buy and what we cook I'm shockucked by you're 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 in Western Europe and obviously places like America just were not really open minded about it Yeah, I think it's probably a bit of both. I think I say one of the characteristics of most fungi like growing kind of damp, humid conditions. I think there's something about the climate you're in. So if you take the UK, for example, know middle of winter, you can't go and find mushrooms out in the wild because it's too cold and there's just not enough environment for them. If you're in the tropics, you can find mushrooms toad stalls all year 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 flavours. A lot of fungal species that we eat, especially the more unusual ones have really quite marked flavours and we know that People are usually quite reluctant to kind of experience new flavourors initially and they have to kind of be exposed to it. And so one of the things, for example, is that many fungal species have a very strong umami flavour, this sort of quite difficult to describe, isn't this kind of rich kind of deep flavor that polarizes people. I think that's a much more common flavor historically in Asian cuisine, for example. ready to embrace this. I suspect in nineteen fifties 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 down to nutritionally speaking, sort of what's in a mushroom Hi, I'm Professor Sarah Berry and I am completely obsessed with snacks As a nutrition scientist, I spend a lot of time analyysing large scale dietary data. and one of the most striking findings from our Zoe research is what we call the snacking blind spot. We observe that about a quarter of our daily calorie intake comes from snacks, essentially making it a hidden fourth meal Strikingly, forty percent of people who have put immense effort into preparing a high quality nutritious lunch and dinner end up falling into a gap where convenience takes over in the afternoon. That specific data is why the team developed the Zoiga Health Bar, a snack bar built with over ten distinct plants, designed by our scientists to prioritize exceptional plant diversity From a formulation perspective, we also wanted to address that afternoon gap by creating a nutrient dense option that aligns with rather than distrupts the nutritional quality of your main meals To do that, we intentionally preserve the natural intact structure of many of the plant's ingredients As a result, the bar is wonderfully chewy and that texture is entirely deliberate. It requires you to physically slow down your eating rate, ensuring that you savour the snack at a much more measured and natural pace With such a range of plants inside, it has seven grams of plant protein, eight grams of fiber and less than four grams of sugar It's still a little sweet though, thanks to the seventy percent dark chocolate and the raspberries and goji berries, depending on which flavour you choose You can find out more about the new Zoe Gut Health bar at Zoe d. com forward slash snack bar 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 mushroom that you buy from you know, the supermarkets, white or brown, big cap on the top. It's aaragus species. And we know quite a lot about that Mushrooms are often used to replace meat in sort of vegetarian type cuisine, and it's a good replacement. So they have more fiber, definitely than animal products, notot as much as some of the kind of really fibrous sort of whole grain food. I wouldn't recommend substituting your granary bread or your oatmeal with fungi, but they are quite healthy in terms of fibber Good levels of protein Ver low levels of fat, particularly saturated fat, so that's already promising. But the thing that gets people quite broadly excited, I think about asushoins 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 mycelium 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, relelatively rare compounds like selenium or also quite often accumulative eye mushrooms. And then last of all, they're pretty good at making vitamins. so they make vitamin B, vitamin C. 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 for our immune systems. so people often talk about Mushrooms been a great source of bititumin D. orth that is slightly more complicated than that I asked the beginning, is it true that mushrooms contain vitamin D? And I think we often think about that as something you get by been in the sun, where is the reality You're right, so we make it by being in the sun 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 Raini or Britain, but you do need a bit of sunshine to make vitamin D Dietarily, we get it from a variety of foods, 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 climes like the UK or Northern US to make enough isism indeed. So that diet beces really important And mushrooms often taged as a great way to get vitamin D because they make vitamin D sometimes at very high levels. There are two caveats there though. The first is that the amount of vitaminia they make is very, very variable between species. So for instance, if you think about oyster mushrooms, which you could now buy in most supermarkets They actually, on average make about a hundred times more vitamin D than your routine field mushroom that might be next to it in the shelf. 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 capap and it doesn't matter whether there's white or brown. Yeah. button mushrooms, field mushrooms, the crown you might have on your English breakfast or mushrooms on toast or whatever that So they said they do produce vitamin D, but they produce less. And so you said oyster mushrooms create a hundred times more vitamin D than like the typical mushroom that I grew up with. And I thought was the only mushroom probably when I was fifteen. Pretty much, yeah, exactly. And that's 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 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 five minutes later and buys them, they'll have almost no vitamin D in them because they won't have see much sunshine The longer they see UV light for, the more vitamin D they make. And so you might be able to you know you might have seen in shops vitamin D enrich mushrooms, which are essentially mushrooms haveve 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 is a spontaneous chemical reaction. So what's happening is a molecule in the membrane of the fungus called agosterool 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 bititumin D in 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 it' 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 because you then said, well, then eat eight to nine mushrooms and I've had my daily amounts. 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 it's obviously there's a variable art here, not least because mushrooms vary in size. But you know, as a very ballpark sort of estimate, you know, fifty to a hundred 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 No, not necessarily. So as you can imagine Not that many mushrooms have been studied. There was an interesting study a few years ago looking at the quantity of vitamin D in various commercial mushrooms. I think the winner actually was the Bolite, which is a kind of slightly exotic fancy mushroom that not many people have eaten. so It's hard to buy that one from your supermarket. But if you get the chance, they have, know I think that's five hundred times as much as your typical turn or peel mushroom 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 mushrooms do make some vitamin D. So 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 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. it's not particularly bad. yeah, there were several with 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 aggosterol and therefore more vitamin D made in the gills, so in the kind of fluffy bit under the mushroom than elsehere, but I wouldn't you know I wouldn't take the effort to turnar 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. So you need the UV to make the conversion work. but actually even winter sunshine has a reasonable amount of UVs. if you think about one of those gloriously winter crisp days in Boston, for instance, you know putting your mushrooms out will be ine actually would do quite a good job there. And I think the other point is that this is 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 having milk on your breakfast and a mushroom, you're still doing pretty well. Soah, I wouldn't worry too much about that. I mean clearly, if you live in sort of northern Sweden and you've got twenty three hours of darkness, it's not going to be such a great trick for you in the winter 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 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. Re good? Yeah What is that? and why is it that some scientists apparently saying it should potentially be classified as a vitamin. so Eergathionine is a very interesting molecule. It's a natural amino acid, so people might be familiar with the idea that amino acids are the building blocks of proteins U we as humans make about or use about twenty amino acids to build our proteins, but there are other amino acids that we don't make we don't use that are use in other organisms. And Eergath thionine is one of those So it's made by fungi in particular and In laboratory studies, it has quite potent antioxidant anti inflammatory effects. So antioxidant, people might be familiar with this idea of reactive oxygen species. or 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. And it is thought that reactive oxygen account for quite a lot of cellular damage as we age in particular. It is 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 yourself So reactive oxygen, not great Ways to mop up and dispose of reactive oxygen are therefore thought to be beneficial in protecting us from damage and helping delay aging and ergaenine 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 And so there has been quite a big kind of interest in whether eating those mushrooms will give you lots ofra thionine 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 listening to this, I wouldn't race out and order yourself for 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 egaionine, it seems to reduce that. Um No really good clinical data suggesting broader health impacts in it. But as with all science,, there's a lot more to do in this space One of the really big mysteries, I think to ergathhinin is we, humans, have a specific protein that is used to take ergathhinin into our cells 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 of typical way of testing these things is to remove it genetically from mice, for example, from thoseose might 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 that protein that takes up ergathhinine varies between different humans. So different populations have what's called polymorphisms variation of this We don't really know 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 and I stress associated rather than causative, but associated with Crohn's disease And so if you carry that particular type of viry receptor, you appear to be more at risk of Crohn' disease We don't know why and it may be complete you know red hererring correlation, but yeah, a lot of interest in egaying So this is one of these examples where we're getting access to like this very early scientific insight. But you're not suggesting that we all have to go out and make sure that we're getting enough gothionine from our mushrooms and we're all going to live another five years of healthy life. Yeah. I mean, it's kind of like the scientific equivalent at that moment when you've finish your flat pack furniture and you've got this thing left over and you think, this looks like he's done really important, but I don't know where it goes. And we're at that point, I would say All mushrooms have like high levels of this ergothionine, or is this only in particular mushrooms? So not all mushrooms produce ergothione, but it is relatively widespread. So it's very rare in other branches of life so plants they make it, animals don't make it. The places it's made naturally are quite a lot of fungal species and in the cyanobacteria, so these photosynthetic bacteria that are associated with things like algal blos and the sea, obviously We don't eat those. So mushrooms are a best bet. levels vary in different mushrooms and we don't really know how they vary in different species. We also don't actually know what a sensible level would be. So that has neuroprotective effect. 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 also. So if I was having like a ard like buttter mushroom? is there likely to be some ergothionine in it? Yeah, there is. Your standard mushrooms have some levels vary. And again, we don't really know what a good level is. So I mean no evidence of harm, that's always a positive thing. But I think we're definitely far from saying this is some kind of magical cal And so weve talked about vitamin D, we talked about this gothionine. You mentioned at the beginning that there's quite a lot of fiber in these mushrooms. Are there any other nutrients that on like helpful for us that are in mushrooms Yes, so most of ns producce vitamin B and vitamin C and they also, I think we mentioned earlier, they harvest these kind of minerals like potassium and selenium and they do quite a good job of that actually. so generally there's quite a lot of kind of Tace elements or minerals that are in there in mushrooms is good for you. I'd love to talk now about some of the health claims that surround mushrooms. So less about the nutrients and more like what does this 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 traditional medicine, apparently for thousands of years But I'd really like to know what the science says. Is there any evidence that suggesting eating mushrooms is linked to either healthier lives or longer lives. Let's focus first of all on kind of your classical supermarket mushroom. 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. A couple of caveats. One is they're usually done by what's called recall studies. So people say, Jonathan, what did you eat last Tuesday? No, 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 etcetera, etcera. 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 mushroom, then actually that will have a benefit because we know that too much red meat is bad for you. So there's a thing about eating mushrooms as part of a varied diet that's good, but as a kind of magical food 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 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 commerce, but you know it's a bit like talking about plants. you know if I say to you does eating plants correlate with long life, Well, yes, it definitely does. if you don't eat your plants, you' not going live very long. So I think there's a big problem there that we talk about mushrooms generally were'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 cultures, it's a very small number of species for a very short period of time. And those are the areas, of course where most of these long studies have been done. so the data is not just the data is not there, but the experience of people is not there to draw on. That might change going forward s that people eat more species. There is the potential to really look in more detail, particularly in other cultures where a broader diversity of fungi have been een for a longer period of time And maybe we'll see something interesting then? 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 Yeah, one of the things about Fung Gy is this is a huge dvice roup of organis, right, and a half million species. And they are amazing chemists. so they can produce just wild molecules. And perhaps the best example is antibiotics, right? Penicillin is a fungal product. I mean now we make it synthetically, but it was a fungal product. And so They can make incredibly impressive chemicals. So you know at face value, might mushrooms in inverted commerce help us forever. abbsolutely because somewhere out there might be a species making something really important. If we're thinking about kind of the small number that we e A the moment, and it's part of regular diets, there's been quite a lot of interest in whether particular species might help protect your brain. and lions's mane is the one that's often quoted as a kind of know, lions's mane fungus live forever. 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 lions made and actually some other species seem to in a laboratory setting in a dish stimulate nerve growth. And so, you know, At face value, you might say, well, creating a few more neurons especially if you're losing 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 demonstrating slight improvement or a slowing in reduction of brain capability in people with early mild cognitive decline. smallmall studies, not highly replicated yet, so you know be cautious, but perhaps slightly promising There was one interesting study that people often talk about a lot on social media where people without any cognitive decline, relatively young people showed an improvement in their mental score or a kind of classical test, which actually is a test where it's very rare to see things that improve that score in people who don't have cognitive decline. so you might see online people say, wow, your IQ will go up if you eat this, you know, which is of based on those kind of studies. Again, very, very small, very limited There hasn' been at least one study which has shown the opposite, which has shown if you haven't, your ability to recall words drops. so Like 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, 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 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 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 into your lifestyle, there's no evidence of harm, but I definitely wouldn't you know guar out of your way to take a particular mushroom supplement in the hope that it will help you live forever The other I think big area that I read a lot of claims is around immune health and inflammation. L we've seen more and more this overlap between that and the microbiome. 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 high level of long term inflammation living in the Western world compared to the past. Is there any evidence that eating mushrooms can have any beneficial impact there? So I think it's really important to think about again about this kind of of the fungal kingdom here. And you know, because I spent quite a lot of my life working on fungal diseases that kill people, 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 when 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 A athes foot are definitely not great. although that's more in the annoyance. But there are a hand for fungal species that are potentially fatal, 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've genetic disorder arrive HIV positive or something, you know Dietarily absolutely fine, but you know if you read someone's magical thing about sniffing a fungal spore, Just don't do that. But that 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 humans and other animals That's largely, I have to say because the immune system has evolve to react to and get rid of fungi. It's not 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 beta glucan inside that cell wall. That's a really potent immune stimulus. So if you put beta glucan 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 beta gllucan as what's called an adjuent to help some vaccines really generate a good immune response. And so they' definitely imme fun guy. less clear is the kind of ability of imun a fungi to suppress the immune system. So there are specific examples, particularly in some pathogenic fungi of molecules that the fungi used to deliberately suppress the human immune system That's for their own advantage, right? That'cause they wanted to grow. And so I definitely wouldn't recommend people expose themselves to those too unclear at the moment whether Similar molecules in fungi that are not harmful might be beneficial. So yeah, sort the juryies through out. probablyrobably 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 sugars and the carbohydrates that fungi make are really good kind of foodstuffs 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 want of a better word, and also the good microbiome can have a very strong positive effect on immune system So it's interesting, you're wrapping on a topic that obviously, we love on 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 microbes to sort of break it down for me. Yeah, exactly. So there' know, and we often sort of overlook I think the fact that your microbiome is this wildly complicated ecosystem. And if you think about the relationship bacteria and fungal species mean evolving together for youity far longer than we have. And so there are some really quite complicated signals. So if you look, for instance, out in soil, you know there are really well documented 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 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 bacteria that live in your gut Are there any funguses that 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. fung and therefore, our immune system does not play nicely with them. That's a really good and very, very live topic. if you' go into social media, lots of people with strong views there Historically, you're right. so people have historically s said fungi growing in your gut bad thing. And in some circumstances, that is definitely true Like most things about a 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 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. And I think kind of an emerging view that there are definitely some species that are probably quite good to haveving your gut. stillill very unclear which ones those are and what they might make the difference for them. But I think that's sort a realization that fungi are kind of everywhere and a part of your natural microbiome very important. And in fact, outside of the gut, so skin, for example, know we' covered in interesting fungi They do all sorts of weird wonderful things. My favourite example being something called malesthesia that grows only really on the human head and in fact it is only able to reproduce in the presence of human sweat excretions. So there you go You're now kidding me. Nope, There is fabulous demonstration that this particular fungus is completely required. so I have a colleague who says it's a creepy feeling to think that there's an 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 sweat that comes off from the human head. Yeah, it's the oils that you produce in your head that seems to be a signal for it to spororeul late to produce the reproductive 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 people saying there's fungi that absolutely only coexist with us. You know, you might think that's just a parasite, but it's your view that on the skin some of these fungi are actually beneficial to us? Yeah, absolutely. And in two different ways. there are probably some species that are genuine sort of symbiant. so they're there, they never do any harm and they're kind of good for you know for 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 species that are sort of at face value potentially bad news. but their presence helps with this kind of maintain a normal immune system. So one that's often talked about is Canada. And there's a sort of whole world out there of kind of Canada syndrome and Canada things. And So Canada is absolutely a fungal pathogen, that can cause serious disease. It can cause vaginal thrush oral thrush sometimes systemic lethal fungal infections But all of us have Canada all the time. if I'm going to go and swabap my armpit, you'd find Canada 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 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 is true. So they produce in their cell wall this moleule that mentioned earlier, beta glue can. So the main structural component of the cell wall is chitine, that thing that's in lobsters and beetles and things But they also have this layer called beta gllucan and beta glucan is a' a it's a polymer. so it's a chain of sugar molecules, glucose molecules We talk about bitter glue can, 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 their structures are all quite different However, what appears to be pretty clear now is that when we eat beta glucan, it can kind of form a sort of gel 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, and then essentially getting pooped out the other end without you taking up too much. This is the same group of molecules that is what makes oats really good for you. So our recommendation to eat oats, oats are greater helping to lower cholesterol Fungi produce less better glucan than you have in oats, but nonetheless quite a significant amount. So if you're already having oat porridge 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. Are you a massive mushroom lover but some of your family are not convinced Why not share this episode with them right now And explain why you're right I would like to talk about actionable advice about how can I actually add mushrooms successfully into my diet. Could we talk about the cooking for a minute? Be I always feel that When I cook mushrooms, it feels like the darn things basically disappear. There's really big. You cook it on some heat and it just like shrinks and shrinks. And I've always sort of felt well I've probably killed everything that is of any value because it all shrunk away. Is this right? Not necessarily. So heat does remove particular vitamins, know levels of vitamins drop quite drastatically when you heat especially for long periods of time Having said that, of course depending what you're doing with your mushroom you might not be heating for very long. So if you're kind of frying a mushroom, know if you think about those big fat, delicious field mushrooms, you know, you might give it A minute on one side and thirty 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 C and C, but also things like potassium are very water soluble. So if you're gonna boil your mushrooms and then throw away your thing they were boiled in That is leaching 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 if you've just moved your potassium from inside the mushroom to outside. and a bit like I think how it was brought up to do carrot. You know, youre put in a great big pot of water then you throw away the water, it's like literally you're throwing away the good stuff. The good stuff. Yeah, exactly. I mean, my usual, you know, best rule is the best way to cook something is the way that you want to eat it. You know, if you're someone who 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 be used at all What about preparing the mushrooms? One the thing I'm always duppp by is the 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. It also puts me off a bit eating it You know, back in the old days you say, oh, you should peel your mushrooms, actually, you know That's of relatively if you're worried about the dirt component, there's relatively limited value in peeling because as we know bottom bit it doesn't have a skin on to peel anyway and the stalk doesn't and on so you're still know,'re not removing that much de. So I wouldn't worry about peeling for sort of aesthetic and general kind of taste reasons. It's a good idea to give them a polish off or a wash off something and to get rid of you 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 becausecause of the way mushrooms grow and the fact they're quite difficult to clean well That is potentially slightly higher than with other foods. So if you think about 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 your mushroom straight from the field, You know, you've got no control over what's on that mushroom. And so as with all foods, the risk of the potential food poisoning is higher. You know, I might caution against eating that one raw The last thing say is there are some compounds in many fungal species, including fungi that we eat which can be slightly harmful I want to kind of caution here because there's kind of level thing, but there are molecules called hydrazines, for example, that in laboratory studies appear to be damaging for DNAs, they' potential carcinens 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 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 poising reason and partly for this kind of question of residual damaging agents. 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 mushroom. Yeah, I think if you can get over the psychological barrier of eating a bit of sterilized horse manure with your pasta sauce, you're fine. Itould' 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 that you really dislike. So I would encourage people to kind of go out and tryry it different mushrooms because there's lots out there and they're all very variable. Loads of people, I think, like you said, your son and my son also 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 and you're an adult, you think I don't like mrooms but I haven't tried them for ten years, give it another whirl because maybe they're not as bad as you remember This is a hugely dimverseed kingdom So we have to think about this not as mushrooms, but as vegetables in the same way that a courggette is not the same as a sweet corn. And so I think kind of testing different ways, using them in different kind of settings is a really good thing to do Think about the way of cooking it, so 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. And so there's a sort of sense of the diversity of mushrooms out there and also the kind of way you're preparing them And last thing I think, is think about the kind of meal you're using them in and the strength of experience. So know I think there are a lot of people out there, for example, who've had a very bad experience with truffles because they get this thing that looks absolutely timeiny and you think, oh, I'll chop that up and throw the whole thing in and then they realize that know, they're ting truffle for a week afterwards. These are really potent species, some of them So go steady, try it as you go, a bit like think of it the maybe as a bit more like spices than you know kind of a core component. if you're thinking about these more unusual ones and test the flavours 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 as the Wesn 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 listen to this and 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 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 of your family doesn't like mushrooms, 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 many a child who avows a hatred of mushrooms, but if you chop them really fine and put them their pasta source, you know they won't particularly notice. These days you can quite often buy them from sort of supermarkets kind of mixed of different mushroom. So If if you're someone out there who's only ever had the classical kind of white butter mushroom, you're like,, I wonder, you can pick up a kind of mixed box from mainstream supermarkets and give it a whir, 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 you know and then if you really get into it, you can discover a whole world of interesting pig's 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 there 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. We don't have the data on that yet obviously in the same way that we do for plants. 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 a 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. So think about that kind of diversity, partarticularly when we thinkking about the impact on the microbiome. 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? I do mushrooms. I love mushrooms and actually, I mean like many people, I'm sure listening to this, mostly it's your traditional kind of field mushroom type thing. But you know if I get the chance, I do like an oyster mushroom in particular, the occasional truffle You know, if I'm eating a mushroom, my kind of favorite way is fairly sort of straightforward. So you know, Hooper mushrooms next to w Elish breakfast is great. 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 lasting on a Sunday at supermarket, they're usually sell them off to cheap because they're going be horrible tomorrow You can stick some breadcumbs and some lemon on that and a bit of cheese on the top. stick it under the grill. Great and relo and the cheese is not so great for you, but everything else in it 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 how to add more mushrooms to their diet like next week. You've given us many tips, but what would be your one tip? Can I do a tip and an antiip? Yeah So my anti tip is please don't do this by going out and thinking that thing looks like a mushroom on my lawn not going to pick that. That's a very bad idea. Do go to a supermarket, reputable retailer first. That's my anti tip. My top tip, I think, 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 I'm gonna 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 pea. Think about mushrooms as a kind of vegetable component that you can put into pasta sauces or things rather than as a special thing that you have to somehow put your mushroom cook hat on to deal with I love it Robin, I'm going to try and do a little summary and just correct me where 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 deep level. The other thing I think, which is extraordinary is this idea that humans are actually closer to fungi than plants are to fungi. does sort of transform the way you think about them is clearly being the source of all of these compounds that you're just not going to get, even if you are eating a lot of diverse plants. That definitely shifts my thinking about like, oh, I'd really like to have more of these mushrooms in my diet because I'm really trying to get that diverse diet And that one of the reasons why they probably work is you're saying, mushrooms are a great food for your microbiome. So actually your microbes are going love this, they're going to feed a whole bunch of good microbes. They can break them down in a way that our body can't and then give us these other benefits I clearly need to have some oyster mushrooms in my diet because apparently there's one hundred times more vitamin D. And since I do live in northern climes in the winter, I can see the oyster mushrooms that I need to remember to put in the sun are a way forward There are some amazing nutrients that are inside these mushrooms. and you describeed this thing that I had never heard of before, the ergothionine that is like a whole amino acid that I didn't even knew existed, that I can't make, that I don't get from plants. And you said like in the lab, it has some really interesting properties. For some reason, like all our human cells can take it in but we don't really know what it does. And interestingly, even just like a button mushroom have this. And this is just an example of the way and like how unique they are. and you talked about them being full of potassium and selenium and vitamin D and vitamin C and beta glucants, all of these things that you don't have The other thing that I was really struck by is the idea that we probably all do have fungi in our gut, but it's just at very low levels compared to bacteria. So it's going to be small. And the latest science is suggesting that we shouldn't think that all fungi is bad for us just because we know that you know you can have overgrowths in various ways So actually probably it's natural and good to have these like low levels inside us. And I think that would be a fascinating thing you to understand more in the dature as this continues to grow And then finally, we talked about how do you get mushrooms? And I think what striking is Any way that you get the mushroom is basically going to be good. So like a dried mushroom, it's still going to be good. It's not like you've lost all the value. If you cook it, it's actually still going to have benefits. The only thing to be cautious of is if you boil it, make sure you drink the liquid. otherwise you are literally putting it into the liquid and throwing it away and that it's very easy to add because it is something that you can eat as a side. So if you're finding it otherwise difficult, you can always just put fry some mushrooms, put it on the side. And so for me, like my final takeaway is I need to stop thinking about it as occasionally I have this special mushroom dish and just think I need to make sure that I have like mushrooms in my supermarket shop each week so that I am eating some mushrooms every week alongside the rest because I'm just going to up this diversity and it's this amazing whole new like kingdom of things. like surely I should be trying to get some of that into my diet That sounds like a perfect summary. I hope you've convinced your son to go into the world of mushrooms Hosting this podcast means I get to quiz world leading scientists every week about how to improve my health But I'll be honest with you But for a long time my snacking habit was completely out of sync with the science. I hidd an energy slum grab a snack bar and usually inhale it in two bites while looking at my phone I knew that the ingredients were a bunch of artificial additives and emulsifiers But honestly, I was hungry And usually there was nothing else healthy to eat It wasn't until our chief scientist Sarah Berry explained the physics of snack foods on this show. that it finally clicked. Highly processed bars are engineered to be eaten fast and release their sugar immediately. which in my case caused a shock. Spike and then crash in my blood sugar. leading a few minutes later to a collapse in my energy and a spike in my home In my opinion This is a cynical move by big food companies to make us eat more. I was furious But Sarah said she thought we could solve this She came back a year later. with the Zoe G got Health bar. and had done something completely radical. She'd left the natural cell structures of the plants intact The first time I tried a sample, I realize you physically cannot rush it. It tastes great