Mushrooms as medicine: Uncovering the health secrets of fungi

Mushrooms are a regular addition to recipes and have been used in medicine for centuries. And scientists continue to discover their incredible health properties and pivotal roles in nature.

In this episode of ZOE Science & Nutrition, we speak with ZOE’s Scientific Co-Founder Prof. Tim Spector, an avid mushroom enthusiast, and Dr. Merlin Sheldrake. Merlin is a biologist, author of Entangled Life: How Fungi Make Our Worlds, Change Our Minds and Shape Our Futures, and a self-proclaimed “mycophiliac.”

Episode summary

Fungi form their own “kingdom” within nature. It's just as diverse as the plant and animal kingdoms, including an estimated 3.8 million species. Mushrooms are the reproductive parts of some fungi. 

In a very real sense, fungi have shaped our world. Without them, plants could never have colonized the land all those millions of years ago. In their incredible variety of forms, they still underpin life on this planet.

Unlike plants, fungi don’t photosynthesize — they actively search for their food using root-like networks called mycelia.

As mycelia contact plant roots, they strike up relationships, providing the plants with nutrients they lack in return for sugars and fats that fungi can’t create themselves.

Aside from fungi’s vital role in the natural world, researchers are increasingly interested in mushrooms’ medical applications.

For instance, so-called magic mushrooms are currently making waves in psychiatric research, an area that sorely needs better interventions.

Beyond the psychiatrist’s couch, other scientists are probing fungi's potential role in cancer treatment. Already, there’s evidence that these delicious lifeforms could help improve responses to cancer treatment, leading to better outcomes.

Another compound produced by fungi — called ergothioneine — has been heralded by some as a “longevity vitamin.” Although this title is likely overblown, there's evidence that ergothioneine might support your immune system and help reduce cancer risk.

If you’re considering upping your intake, where should you start? The good news is that all edible varieties will likely benefit your health.

Each mushroom species contains a unique profile of healthy, natural compounds and fiber. They can be enjoyed fried or fermented and complement all manner of savory dishes.

As is often the case, eating the whole mushroom (rather than a powdered extract) is probably the best way to get the health benefits.

But dried are just as nutritious as fresh, and sometimes even tastier. And the more species you eat, the better — but don’t pick them wild unless you know what you’re doing: Not all mushrooms are your friend.

Transcript

In today’s episode of ZOE Science & Nutrition, Jonathan, Merlin, and ZOE Co-Founder Prof. Tim Spector ask: Why are mushrooms so special?

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Episode transcripts are available here.

Is there a nutrition topic you’d like us to explore? Email us at podcast@joinzoe.com, and we’ll do our best to cover it. 

[00:00:00] Jonathan Wolf: Welcome to ZOE Science & Nutrition, where world-leading scientists explain how their research can improve your health.

I'm your host Jonathan Wolf, founder and CEO of ZOE. Today, we dive into the captivating world of fungi and mushrooms, and learn about the surprising reasons why they're so important for us.

Fungi expert Dr. Merlin Sheldrake and my scientific co-founder at ZOE, Professor Tim Spector, take us on a psychedelic tour of mushrooms, including why they're a promising treatment for debilitating mental health conditions like depression. We'll also hear how the chemicals in mushrooms might be protecting us from other diseases.

And of course, why eating more mushrooms is beneficial for our health.

Merlin is a biologist and the author of the best selling book, Entangled Life, How Fungi Make Our World. Tim is one of the world's top 100 most cited scientists and a professor of genetic epidemiology at King's College London.

Merlin and Tim, thank you for joining me today. I'm really excited about this one because I really enjoyed the book and those of you who are on video can actually see the new version of it has these amazing pictures in it which when I read it, it didn't have the pictures and now suddenly it all makes way more sense.

So I think that is the ultimate book for people who love really getting this vision into something you haven't seen before. But at this point, no one probably has any idea what we're talking about. So what I'd like to do is start with a tradition we have here, Merlin, which is a quick fire round of questions. Are you up for that?

[00:01:48] Merlin Sheldrake: Sounds good to me. 

[00:01:49] Jonathan Wolf: So we have very strict rules, which are always tough for scientists. You can say yes or no, or if you absolutely have to, you can give us a sentence. You're willing to give it a go? 

[00:01:59] Merlin Sheldrake: I'll try. 

[00:02:00] Jonathan Wolf: All right. Are mushrooms and fungi a kind of plant? 

[00:02:05] Merlin Sheldrake: No.  

[00:02:06] Jonathan Wolf: If there were no fungi, would we be alive today?

[00:02:09] Merlin Sheldrake: No. 

[00:02:10] Jonathan Wolf: Do plants rely on fungi as much as we rely on gut bacteria? 

[00:02:16] Merlin Sheldrake: At least as much. 

[00:02:18] Jonathan Wolf: Brilliant. Well, we're going to go into that in a bit more detail. Now, Tim, do all mushrooms have the same health benefits? 

[00:02:23] Tim Spector: No, but they're all good. 

[00:02:25] Jonathan Wolf: Are dried mushrooms as good for our health as fresh mushrooms? 

[00:02:30] Tim Spector: Usually and sometimes more.

[00:02:31] Jonathan Wolf: And finally, do psychedelic mushrooms have the potential to revolutionize medicine? 

[00:02:38] Tim Spector: Absolutely. 

[00:02:39] Jonathan Wolf:What's the most surprising thing about fungi that you've found in your studies? 

[00:02:42] Merlin Sheldrake: It's very hard to answer that because there are so many surprising things. I'll choose one. The fungal networks in a teaspoon of soil could stretch from anywhere from 100 meters to 10 kilometers.

[00:02:54] Jonathan Wolf: Merlin, can we start at the very beginning. Because I think most people here, like me, didn't know what a fungi was. What are fungi and are they the same as mushrooms? 

[00:03:04] Merlin Sheldrake: Fungi are a kingdom of life, so that's as broad a category as animals or plants. So there's lots of ways to be a fungus, just like there's lots of ways to be an animal as lots of ways to be a plant.

But they're not plants and they're not animals. Mushrooms are the reproductive structures of a small group of, well, a large group, but a small, proportionally small group of fungi. So mushrooms are the places where fungi produce spores, which help them disperse themselves over potentially large distances.

So when we think of mushrooms, we're just thinking of a small part of the overall life of a fungus, which is usually in the form of a network. Most fungi live most of their lives as networks of branching, fusing cells called mycelial networks. 

[00:03:51] Jonathan Wolf: And so that means I should think about mushrooms a bit like a fruit. So it's like a tomato or a pear within this thing that isn't a plant. 

[00:03:58] Merlin Sheldrake: It's analogous to the fruit of a plant, except that the tree, say the apple tree that produced the apples, is underground. And the mushrooms you see usually are sticking up through the ground and you're not able to see the rest of the tree.

[00:04:10] Jonathan Wolf: Why aren't they a plant? Because it feels like, you know, they're not an animal, and then they're not a bacteria, so in my very simple view of the world, they're a plant, aren't they? 

[00:04:19] Merlin Sheldrake: I think perhaps the most important difference is that plants on the whole, photosynthesize. So they produce energy from the light coming from the sun and from carbon dioxide in the air. And it's a really fundamental process on the planet, photosynthesis. It's kind of like they're eating air and eating light to produce the energy they need to grow and do the things they do. 

Fungi don't photosynthesize. So, like us, as animals, we have to find food in the world. ready made, as it were, and put it inside us. Fungi have to find food in the world and consume it. They can't make their own energy containing carbon compounds like plants do. 

[00:04:57] Tim Spector: It will steal the energy from something else that's made it. 

[00:05:00] Jonathan Wolf: So that's fascinating. So they don't have the ability to photosynthesize, they can't take the energy from the sun. But they can't just walk around, right? Like a animal or even, I think, like a bacteria that's sort of free. 

Does that tie into what you're talking about before about, you know, these incredible number of roots that you were describing? 

[00:05:22] Merlin Sheldrake: Yes. So they grow into networks, mycelial networks and what these networks allow them to do is, whereas animals tend to find food in the world and put it inside their bodies, fungi put their body inside their food.

[00:05:35] Jonathan Wolf: Which sounds disgusting. 

[00:05:37] Merlin Sheldrake: Well, I mean, not disgusting if you're a fungus. And the way that they do this is by growing these networks, which allow them to bury themselves, insinuate themselves within their food source. Because they're highly branched, they can make contact with as much of their surroundings as possible, which they then digest by releasing enzymes and other digestive compounds which allow them to break down their surroundings and absorb those nutrients into the networks.

[00:06:01] Jonathan Wolf: Nobody told me anything about this when I studied my school biology. I don't feel like people are constantly talking to me about fungi. Do they matter? 

[00:06:11] Merlin Sheldrake: Well, I'm bound to say yes. But I do believe that they really do matter. And I'm not alone. One of the things that they're able to do, remember this is a big group of organisms, a kingdom of life, but on the whole, fungi are metabolically ingenious. They're chemical wizards. 

They can produce all sorts of fascinating chemicals that allow them to interact with the world in strange and remarkable ways. So what this allows them to do is to play really important roles in the biosphere for example, by decomposing wood. If all the wood that plants produced piled up, unrotted, then we'd be buried kilometers deep in unrotted forests.

Of course, we wouldn't exist in that situation, but you get the, you get the picture.

[00:06:55] Jonathan Wolf: And you need the fungi in order to break down the wood?

[00:06:57] Merlin Sheldrake: So wood wouldn't decompose if it wasn't for the activity of fungi, which are able to break down the wood by producing an arsenal of chemicals and enzymes that allow them to do so.

But they aren't just powerful decomposers. They also play really important roles in making life on land possible. So all plants, for example, depend on fungi. On symbiotic fungi that live in them or on them in order to survive. Plants would not have made it out of the water and onto the land 500 million years ago, were it not for the fungi that they formed relationships with.

So they're symbionts, they're decomposers. And through all this activity, they play a part in regulating the composition of the atmosphere. And because when they decompose things, they release carbon dioxide. When they support plant life, they help pull down carbon dioxide into stable forms in the soil.

They also make soil by decomposing organs. You can think about soil as the kind of the guts of the planet. I often think about it like that. And fungi are key players in the life of that gut system, if you like, in the soil. They hold soil together. They form a sticky living seam that holds soil together.

If you take away the fungi, the soil will wash away. They play all sorts of roles like this. You can think of them as ecosystem engineers. 

[00:08:14] Jonathan Wolf: Can I touch for a minute, because you mentioned this word symbiosis, which definitely brings me back to like 15 year old biology. And I feel like it's really interesting because we talk a lot about sort of gut bacteria and this realization.

And we have Tim here about how important they are for us and that these bacteria aren't all our enemies. But actually, it seems clear now that there's a lot of ways in which the human body and bacteria actually fit together. 

I think there's something analogous that you're talking about between fungi and plants, but how essential are fungi for plants and how does that fit together?

[00:08:43] Merlin Sheldrake: Yeah, so symbiosis just means living together, right? There's lots of ways to live together, like we know as humans, there are lots of kinds of relationships that we can form. Some of these are healthier relationships than others. Some are more productive, constructive relationships than others, and some can be really problematic. And it's like that in the living world at large as well. 

So, fungi form relationships with plants, perhaps in the most important way, by living in and around plant roots, extending their webs, their exploratory webs into the soil, and foraging for nutrients, like nitrogen or phosphorus, which they're able to find more easily than plants can.

They transport this nitrogen and phosphorus back to the roots, and they exchange it with plants for sugars and fats that the plants have produced in photosynthesis. So, they have a trading relationship with plants.

[00:09:33] Jonathan Wolf: Trading, meaning they're giving plants something good, and the plants are giving them something back.

[00:09:39] Merlin Sheldrake: Something good, yeah. They, on the whole, both are benefiting from this association. It's what you might call a mutualism, but it's based on the exchange of resources. So, the plant's getting something it can't so easily get by itself, the fungus is getting something it can't so easily get by itself, and together they're able to extend their reach and do things that neither could do alone.

[00:09:54] Tim Spector: The links between soil, health, and gut health are just so obvious. And that, you know, and anyway, the life of the planet and you know, the healthy human is also deeply interlinked. And it's interesting that the ratio of fungi to microbes in soil is actually a really good indicator of the health of the soil.

And in areas where there are less fungi networks, then that soil isn't as nutritious or it's hard to grow things. So in a way that's just like humans that have, you know, lost diversity of our microbes. We know there are fungi in the human gut, and we estimate that about 8% or so of our microbes are fungal. That's a bit of a guess because they're hard to sequence genetically and they're much larger than the equivalent bacteria. So we don't really know. 

But we used to think of them as harmful inside our guts and lots of clinics everywhere were set up to eliminate gastric fungi like Candida. And there's no real evidence that for most people, they are harmful. And a lot of evidence that they do play a really protective, again, symbiotic role working with the bacteria in this case to maximize nutrition and reduce things like inflammation and keep the gut wall in it structurally really sound and a real defense mechanism, particularly for the immune system.

So we think fungi in the gut are really important for the immune system. So it's really lovely to see these analogies, these crossovers, how yes, they work with plants, they also work with humans and it's a two-way exchange mechanism that's really cool. 

[00:11:42] Jonathan Wolf: Your research is about how fungi can engage with the environment, even though they don't have any, they don't have any brains, right? There's no, a fungi doesn't have a brain. Could you tell us in very simple words, like what you're doing and what it tells us? 

[00:11:56] Merlin Sheldrake: So I'm working with a research group and we're trying to understand the way that these symbiotic fungi that live with plants in and around their roots, how these fungi are able to behave as networks. 

How are they able to live in a changing world, sensing their environment, sensing lots of things, sensing temperature, sensing any number of chemicals, sensing acidity, pressure, all sorts of things. How are they able to sense all of these aspects of their environment? How are they able to integrate all of these different sensory data streams and decide in their way, decide on the right course of action at any one moment.

We know very little about this and so we're looking inside these networks using microscopes and watching the flow patterns like rivers of fluid moving through the network. And sometimes like getting to a junction, going up one way and changing direction and going down the other branch of the junction.

And so it's really exciting work because there's a lot of looking involved. 

[00:12:56] Jonathan Wolf: And when I read it, it reminded me a bit of like these sort of science fiction movies where we experience some completely foreign creature that doesn't seem to have a brain or whatever, but actually turns out to be, you know, cleverer than us.

And I definitely get a sense from you of some sort of awe that this thing is actually much smarter than you would have expected or we could imagine, despite the fact that it's sort of invisible to us and doesn't have a brain. These things that we would classically think of as what's required to imagine that something has any intelligence or capability.

[00:13:28] Merlin Sheldrake: Yeah, I think that's right. You know, one of these fungi might be a sprawl over tens of meters. It might be engaging with hundreds of thousands, millions of different plant root tips. It might have very different environmental situations in different parts of its network, managing uncountable number of trading decisions with these plants and constantly.

Remodeling itself and readapting in these shading relationships to changes in the situation and from moment to moment, from day to day, from season to season. Like these are non-trivial problems to solve and of course they solve them in their way, and they've evolved over hundreds of millions of years to do this.

But yeah, that does boggle my mind. 

[00:14:10] Jonathan Wolf: Has there been a significant human impact on the fungi around the world in the way that it supports plants in the way that we're obviously very aware there is on trees.

[00:14:23] Merlin Sheldrake: For sure. If we cut down a forest and the bodies of those plants were home to the whole load of fungal species that depend on those plants for somewhere to live and for symbionts to live with, for partners to live with.

We cut down the forest, you've destroyed the habitat for a whole load of fungi that no longer can live there. You've also created habitat for a whole load of different types of fungi, right? You might have fungi that thrive on rotting wood. So if a forest is killed by a disease, and you have a lot of dying dead, dying wood around that will create habitat for a different group of fungi.

So again, there's so many ways to be a fungus. It's a little hard to generalize, but on the whole, yes, when we do really huge scale industrialized agriculture, we are often damaging fungal communities by plowing. 

[00:15:09] Jonathan Wolf: I was wondering about that. This constant plowing and fertilizers. Is that, do you get the same density, I guess, of fungi in the way that we do in modern agriculture as we would have done in historical approaches.

[00:15:20] Merlin Sheldrake: No, you disrupt the fungal communities and you get lower fungal diversity and you get less healthy, less active groups of fungi in those places. 

Plants have evolved for hundreds of millions of years to do what they do in association with fungi. So some modern strains of plants, some modern crops, for example, a wheat variety might have been bred to grow quickly when you feed it with loads of chemical phosphorus.

[00:15:47] Jonathan Wolf: This is like giving it fertilizer.

[00:15:48] Merlin Sheldrake: Yeah, give it lots and lots of fertilizer. And so that modern-bred variety might not be so good at forming relationships with their, you know, their companion fungi as a variety that has been grown by humans for a long time before this chemical phosphorus started to be applied.

So on the whole if we're breeding this kind of plant, we're breeding quite spoiled plants. Spoiled plants with maybe not very good symbiotic manners. They're not so good at forming these associations and they might form quite dysfunctional relationships with the fungi that would otherwise be key parts of their lives.

So take away the phosphorus the plant needs, the plant won't survive and nor will it have fungal partners to strike up a relationship with. 

[00:16:26] Jonathan Wolf: I've sort of got this analogy now of plants almost being fed on their own version of ultra processed food, right? So they grow really fast, but in a way that isn't quite right.

And then of course, probably therefore ending up without some of the things that, you know, you would expect to see in a healthy plant, which we then go and eat. Am I stretching this too far?

[00:16:43] Tim Spector: No, it's like if you suddenly feed any animal massively and it balloons up in size, it might have more height and weight, but it's going to lack some of those nutrients and things. Like it's defense chemicals, it's complexity and it's interaction with the world is going to be different because all you're focusing on is the size of that animal or that plant. They're lazy, you know, they just have to sit back, don't have to do much hard work. And the fertilizer just is this massive growth hormone that just pushes them up.

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[00:17:18] Jonathan Wolf: It’s a bit like they've lost their own microbiome. Only in this case, it's their fungi and it's spread out and dispersed rather than sort of sitting inside. 

[00:17:25] Tim Spector: Yeah, they don't care. They don't need it. I'm getting all the growth I need, all these extra nutrients. They're just icing on the cake. I don't need to worry about that. Let's not give the fungi as much and the fungi don't return the favor. 

So I think that's partly it, but also, you know, the heavy plowing, the chemicals in the soil, all these things are disrupting these networks as well. 

[00:17:46] Jonathan Wolf: And Merlin, presumably this is all unintentional, right? It's not the people 70 years ago, whatever we started this big growth in agriculture, like, Oh we know all about the fungi and we don't care. It's just that they were seeking to get more and more food. 

Nobody knew about any of this, I'm guessing, and this is another example of sort of an unintended byproduct. Because we generally didn't realize how complicated the world was, and tended to think that there were very simple answers, and only now starting to realize there was much more complexity underneath?

[00:18:21] Merlin Sheldrake: I think that's fair to say that largely it's been driven through ignorance rather than through people being malicious. 

However, that wouldn't be something you could necessarily apply today, where you have powerful lobby groups for, you know, for the chemical industry, for the big machinery industries, for all of these different parts of the heavily commercialized agricultural world.

I don't think that all of those vested interests and powerful lobbies are acting out of their concern for the soil. I think they're acting for a profit motive. 

[00:18:54] Tim Spector: Can I ask about herbicides and glyphosate, for example, the communist herbicide used. We don't really talk about its effect on, on the fungi and fungal networks. Is there any data on that? Is it resistant to it? 

[00:19:09] Merlin Sheldrake: I've read some studies that suggest that herbicides are damaging and disruptive to mycorrhizal fungal networks. I don't know what context they were studying those studies took place in. I don't know how much these herbicides affect decomposer fungi. Which are also important parts of the soil but certainly there's some evidence that they are disruptive. 

And of course they're disruptive in another way because they kill the plants. Kill plants that fungi depend on and you're on the whole lower diversity of plants in an area means lower diversity of fungi.

[00:19:37] Jonathan Wolf: I'd love to talk now about the role of fungi and mushrooms in human health. And starting with medicine, because I know Tim, that you're quite excited about some of the new things that are coming along. And so could you maybe talk, Tim, talk to us about hallucinogenic or psychedelic mushrooms, which I was definitely brought up as something that my parents told me I should never do.

And now you're talking about it as potentially real treatment for mental health issues. 

[00:20:05] Tim Spector: Yes. Well, mushrooms have been used medically for thousands of years in China, and there's a huge history there that in a way the West sort of forgot about and is recently, you know, rediscovering. The so-called magic mushrooms in the West really seemed to come to light after a family were having a picnic in Green Park in the 17th century.

[00:20:32] Jonathan Wolf:Okay, keep going. 

[00:20:33] Tim Spector: And they were reported by, I think it was the Times, as going crazy and delirious and having to be sort of arrested by the police because… 

[00:20:41] Merlin Sheldrake: Fits of giggles were mentioned. 

[00:20:42] Tim Spector: They were hysterical and they couldn't be sort of, you know, controlled and this made the newspapers at the time. And it turned out they'd been foraging in Green Park and found these mushrooms. And that's really how, at least in the West, this idea that mushrooms had this mood changing effect. 

But some mushrooms, psychedelic or magic mushrooms, produce a substance called psilocybin, which is a very powerful neurochemical in the brain, and it's very closely linked to the drug LSD, lysergic acid.

LSD was around in the 1960s, and it had a brief time when it was thought to be useful therapeutically, and there were studies. You went to Johns Hopkins University, and you were a student, and you enrolled in the LSD study. And they did a group of students there and found that it did have profound effects on these students, generally positive. There were a small amount of them that got rather anxious symptoms, but most had very positive life changing type experiences.

[00:21:58] Jonathan Wolf: And I think Merlin, you actually rather more recently than the period you're talking about, took part yourself in one of these LSD trials, I think in in the UK, if I remember rightly from the book.

[00:22:08] Merlin Sheldrake: That's right in this resurgence of interest in psychedelics, which has taken place in the last 15 years or so, and it was a study into the effects of LSD on the problem solving abilities of scientists.

So they got a lot of scientists, which I was recruited in the tea room at the Department of Plant Sciences. I was working, there was a poster on the wall that said, ‘Do you have a meaningful problem that needs solving?’ And it said call this number, so I called the number because it seemed like I had many meaningful problems that needed to be solved.

It's what you could recruit more or less anyone that way, if they were silly enough to call the number. I was silly enough to call the number and they said that this was a study involving scientists and giving them LSD to see if it changed the way that they solve problems. 

So I thought, I said, well, sign me up and I went to the hospital. And they give you a battery of tests, you know, of psychometric tests and questionnaires and so forth. And then you lie in the hospital bed, they very politely actually made the hospital room less hospital-y. They'd hung hangings on the walls and they had mood lights and music. So you didn't feel exactly like you were in a hospital, but it was quite a thin disguise, I'd say.

Anyway, I lay there and had the LSD and a remarkable experience it was. 

[00:23:24] Tim Spector:Did you solve your problem? 

[00:23:26] Merlin Sheldrake: Not in any straightforward way. But I got a new perspective on the problem. It felt like lots of very familiar parts of the problem landscape became unfamiliar again. And so I could kind of re-examine the situation.

And it felt like there were lots of really helpful insights. If there was not one key solution, there were helpful insights that allowed me to proceed in a way that felt fruitful. 

[00:23:54] Jonathan Wolf: And how was the experience overall? 

[00:23:56] Merlin Sheldrake: Very positive. I had a great time. I had to do these questionnaires to, you know, to assess how you're feeling.

And one of the problems of doing this research, you know, as a scientist, so the scientists doing the study is that they're trying to be objective, you know, they're looking from outside, but they're looking at my subjective state and the subjective state of the other participants. It's hard to be objective about subjective things. 

So they had these questionnaires. One of the questionnaire questions I remember having to answer this question again and again was, how do you rate your experience of infinity on a scale of 1 to 10? This question never ceased to amuse me. Every time it came around every hour or so I would descend into even more intense fits of giggles. And eventually you've pulled some number out of the air. 

But this is not to make fun of the question as an approach. It's just sometimes these things can seem absurd when you're in that. 

[00:24:56] Tim Spector: It's supposed to change your concept of ego, isn't it?
So that's one of the big things. It removes your ego so you can see everything more objectively, that's what people who do this regularly and therapists say. Did you?

[00:25:09] Merlin Sheldrake: Yeah, certainly the boundaries of where you start and stop become more confusing. Feels like you become more porous, that it’s less easy to distinguish you from your environment.

For me, I felt like my mind became a much larger place. It's like I, mostly on a day to day basis, like I spend time in the garden of my mind. But in this experience, it felt like I noticed there was a gate at the bottom of the garden leading to a path, leading into a forest., leading into a much bigger place, which was quite an amazing place to explore.

And that's something actually I brought back with me from the experience. It's, I find it helpful sometimes to remember that my mind is a bigger place than the room that I'm spending time in, my mental room that I might be spending time in at any given moment. 

[00:25:59] Jonathan Wolf: And Tim, what does the latest science sort of show about this? Is this just an excuse to let fancy scientists be able to do LSD without getting sent to jail? Or is there something real here?

[00:26:09] Tim Spector: No, well, I mean, you know, for 30 or 40 years, LSD was seen as a bad drug. 

[00:26:15] Jonathan Wolf: Definitely what I was brought up to believe. 

[00:26:17] Tim Spector: And it got labelled, you know. These bad acid trips and it got labeled the same way as heroin and cocaine and crystal meths, etc. And it turns out that was really a blanket reaction to all drugs and throughout what is actually therapeutically a very useful tool in psychiatry. 

And remember that there's been no new drugs in psychiatry for at least 30 years and they've started to trial, proper clinical trials with proper doses of psilocybin, which is easier to dose than just LSD, and shown remarkable benefits of people with quite severe depression that have been resistant to medication and also some case of anxiety and depression, and also some psychosis as well. 

There's some encouraging signs that it can reset the brain through these chemicals. And so actually changing some neural pathways inside the brain in positive ways. Everyone in that area is super excited by it. And there are many companies now looking at biosimilar compounds.

That’s, you know, again, kind of crazy and thinking how fungi are producing these, these amazing compounds that we're now using as medications for mental health. It just, again, illustrates how, you know, we need to be embracing nature and using all these things together. So I think, you know, in 5 years, we'll be seeing these drugs prescribed.

[00:28:02] Jonathan Wolf: I was going to say, I think you were talking to me the other day about lots of other uses of mushrooms that people are investigating in medicine.

[00:28:09] Tim Spector: There's quite a lot going on in cancer, interesting, and not as a main treatment. There are some sort of test tube studies show that, when you sort of dry these mushrooms and you put them in little test tube plates, you can get immune benefits and you can get anti-cancer benefits. 

But often most things can show that. So the proof is often in human studies. There aren't many of those but there've been several. There was 13,000 elderly people with dementia who had been given lots of mushrooms and reduced their dementia outcomes after six years. 36,000 Japanese were given it and showed to have reduced their risk of prostate cancer. These are observational studies, not trials, so they're not the gold standard. And lots of mouse studies showing particularly things like button mushrooms or reishi mushrooms can reduce, can have sort of beneficial effects.

And I think the most important is these cancer trials. So there are five small studies of, again, these reishi mushrooms which so that if you give it in addition to chemotherapy, so this is adjuvant treatment, you get improvements in those cancer outcomes.

And this was looked at independently by the Cochrane Review, which is a generally unbiased way of looking at it, saying yes, up to 50% improvement. The trials could be bigger, could be better. Yes, we need more of them. Reishi and Turkey Tails seem to be coming out as helping side effects of the drugs and helping them have a bigger immune impact. 

So I think this is where that field is going, is that these have you know, hundreds of chemicals in these mushrooms and fungi are having these benefits on our immune systems that maybe help us respond better to these drugs. And I think this is again, similar to what we see in the human gut as well.

[00:30:23] Merlin Sheldrake: And worth remembering also that fungal enthusiasm, as you said, Tim, is not equally distributed around the globe. And so in East Asian cultures, there's maybe a kind of mycophilia, you might say, more of an enthusiasm for things.

[00:30:38] Jonathan Wolf: Mycophilia is loving mushrooms. Yeah. 

[00:30:41] Merlin Sheldrake: Yeah. Loving fungi, fungus loving.

[00:30:44] Jonathan Wolf: Slightly surprised you haven't turned up with that on your t shirt, Merlin. I'm disappointed.

[00:30:52] Merlin Sheldrake: But in Japan, there's a chemical from shiitake mushrooms, which is used very widely for treating cancer alongside more conventional cancer treatments and also a compound from turkey tail, which is used very widely in quite conventional medical context.

So the research, the science is unequally distributed and some of the reasons why those are not used so widely here is because it's not totally clear how they're working, although it seems to be very clear that they work.

[00:31:25] Tim Spector: Talking about all these chemicals in fungi, there's one that's sort of hitting the headlines at the moment called ET.

[00:31:33] Jonathan Wolf: Tell me about ET, which makes me think of a famous 1980s movie, but it looks a little like a mushroom now I think about it, but that's not I think where we're going.

[00:31:43] Tim Spector: Yeah, ergothionine is a compound produced in many fungi, particularly the, what's called the, the bolete family, which is like ceps and porcini mushrooms, quite high doses of it.

And it's been shown in a number of studies to have these particularly powerful effects on the body, on the immune system. And interestingly, humans have adapted systems to actually take this chemical and bring it into their bodies. 

So it's like a vitamin, some marketing person called it the longevity vitamin, and there's quite a hype around it and you can now buy ET supplements. You know, there are people saying it has amazing powers. But at the end of the day, it looks like you're much, still much better off eating the whole mushrooms rather than these, this, again, this reductionist supplement, which probably doesn't work in that artificial form as much as it would do if you're eating the whole fungus.

[00:32:44] Jonathan Wolf: So you're skeptical, just to make sure I've got that. You're as often like skeptical with extracting the one chemical as ET, quite bullish about eating the underlying mushrooms?

[00:32:55] Tim Spector: Absolutely, I mean, you know, it's definitely a healthy compound when you eat in the context of the whole fungus, the mushroom. Once we make it industrially and commercially and you take it outside that the evidence isn't really clear it's that beneficial.

And that's where marketing takes over. So I think that's what I've learned. So go out and pick those, you know, ceps and porcini mushrooms and have a, you know, fantastic meal knowing that just one of the hundreds of amazing chemicals you're getting is going to be this ET that may have anti cancer properties. You know, it may have all these other benefits, but I think we're better off just by eating more mushrooms rather than these supplements. 

[00:33:39] Merlin Sheldrake: I think this touches on an important point as well, that many of these medicinal fungi have been used for a really long time by traditional cultures and have been known about by traditional knowledge systems include psychedelics as well.

So I mean, it's easy to forget that when we are talking about the stories of modern science, where it can seem as if we're just discovering that these things work. I think a lot of what's going on in these modern scientific contexts is that we're understanding a little bit more about how they work. But many of these fungal species like reishi and lion's mane, and chaga, these have been used for a very long time. 

[00:34:18] Jonathan Wolf: It makes me think of this analogy with aspirin, right, which is from a tree and you're going to tell me which tree it's 

[00:34:26] Merlin Sheldrake: Willow, bark of a willow, 

[00:34:28] Jonathan Wolf:where I think similarly it was used for traditional medicine for thousands of years. This is right. And it's only then much later that we came along and understood in this case, identified, you know, the individual compound and figured out how to mass produce it. So is that’s the analogy? 

[00:34:43] Merlin Sheldrake: It's definitely an analogy. So many of the medicines that are very familiar medicines in the modern pharmacopeia have come from folk medicines. And actually with these more traditional, fungal medicinal fungal species, one of the reasons why we don't know as much as we should is because it's very expensive to do big human clinical studies. And these traditional medicines have been known about for a long time. There's not much IP to defend. So big companies aren't so motivated to do those studies. And it's one of them. 

[00:35:11] Jonathan Wolf: So no one is going to spend a billion dollars to prove that eating a particular mushroom improves your health because they can't lock up the mushroom in the way they can lock up a pill, which I think is very familiar to us, right, Tim, as we think about nutritional science. They just, people haven't spent the money on these studies because nobody can lock up olive oil or, or whatever it is. 

Which is actually a brilliant transition to talk about food. And I think that our listeners will not tune back if I haven't had a chance to talk, really interested to talk about specifically for these, you know, like cancer and, and mental health, but more broadly, Tim, as I said, I love this chapter in your book talking about why mushrooms were so valuable for us to eat.

But can you give me the, you know, the quick rundown again, like why should anyone care about eating mushrooms? 

[00:36:01] Tim Spector: Well, they taste fantastic. They have this amazing range of chemicals that give you this umami taste, this savory taste, which is sort of mimicking meat in, in many ways. And for some people it's better than meat, particularly if you've got a range of different mushrooms, and you've slow cooked them and, or even get more taste if you dehydrate them and rehydrate them in many cases. So you actually get even more savory flavors and more chemicals.

But as well as being super tasty, you know, there's a lot of water in them. So once you've. got rid of the water. They have huge amounts of protein, 25% protein, pretty good amounts of fiber as well. All these chemicals we've been talking about that have a whole variety of, of these effects. The source of selenium, they're actually a source of vitamin D, and they sunbathe like humans.

[00:36:57] Jonathan Wolf: You mentioned this before.  Is it really true that if you leave them out in the sun before eating, they have more vitamin D? 

[00:37:01] Tim Spector: It is. I mean, it depends slightly on the variety, but some of them are really good at converting natural steroids in them to vitamin D, which is a steroid, and basically you can get half of your vitamin D amounts from, from eating portions of mushrooms.

[00:37:18] Jonathan Wolf: Is it just a lucky byproduct for us that these mushrooms are so nutritious and have all of these chemicals we don't access elsewhere? 

[00:37:29] Merlin Sheldrake: In some sense, I mean, it's also important to remember that these, they haven't been busily evolving for over a billion years to give us vitamin D. And although obviously it is irrelevant when we're talking about what it's like to eat them. 

But they need these molecules themselves to do a lot of the basic things that they need to do. So, for example, when we use fungal drugs like penicillin, which is a very famous drug produced by a fungus, the fungus is producing that antibiotic to defend itself from bacteria.

When we use it in our lives, we're rehousing a fungal solution within our bodies, or in our societies. And so I think that you can think of a lot of the nutritional content of mushrooms as something similar. It'll vary from compound to compound.

[00:38:20] Jonathan Wolf: of course. It's interesting. We talk a lot about diversity as we think about what you're eating.

And in a sense, what I'm hearing is like, fungi aren't even plants. So I guess to make it very, think about it this very simple, it's hardly surprising you're getting more diversity in the same way you're describing these fungi. Carrying out tasks that plants can't do. Similarly, it's perhaps not surprising that you might have access to like these different sorts of complex chemicals from fungi that we wouldn't just get through our normal plants, or am I stretching this too far?

[00:38:49] Merlin Sheldrake: I think there's lots of things that fungi can do for us chemically that plants can't. Because they are so chemically ingenious, because they produce all these different compounds to do all these different things, in fact, lots of the chemicals that you'll get by eating a plant have originally been concentrated or even made by a fungus.

Much of the phosphorus that's in your body would have passed through a fungus on its way to the plant that fed you.

[00:39:13] Jonathan Wolf: And is it okay to eat them raw or should I always be cooking my mushrooms? 

[00:39:19] Tim Spector: Unless you're very careful, you're better off I think cooking them. There are quite a few poisonous types and there are other ones that, just by cooking them you get rid of those nasty chemicals and they're easier to eat.

And it's often easier to get the nutrients from them if they're slightly cooked as well because they have this special layer, chitin, which is very hard to break down and gives it that structure. But also they're full of water as well, so if you're cooking them. You, you actually get rid of a lot of the water and you get actually more flavors that way.

So that's my view. I don't know whether you eat lots of raw mushrooms, but I think they taste better cooked generally. And so that's the way I eat them. 

[00:40:09] Merlin Sheldrake: It’s easier to digest, breaking down the cell walls for sure. 

The times when I might eat them when they haven't been cooked, formerly cooked with heat, is when they've been fermented. So if you're eating like a mold, like Koji, which is used to make soy sauce and miso, you haven't cooked. that, but it has been transformed through a fermentation process. 

[00:40:30] Tim Spector: Cold cooking we call that. So yes I've started fermenting mushrooms. It's quite tricky, but they do taste amazing. 

[00:40:38] Jonathan Wolf: And how do you access this? Because most people will feel like if they go to their local grocery store and mushrooms, maybe there's like one type of mushroom or, you know, I think we’er starting to see a few more, but still not very many. 

And I at least have been told by my mother again, I feel like there's a long list of things that my mother told me not to do on this podcast. But one of them was. Not to eat random mushrooms that you find in the forest because you're likely to kill yourself. So how do people, I assume that they're not eating random mushrooms is a good idea, Merlin? 

[00:41:05] Merlin Sheldrake: It's definitely a good idea. 

[00:41:06] Jonathan Wolf: Cause quite a lot of them are genuinely poisonous.

[00:41:07] Merlin Sheldrake: There are some poisonous mushrooms which will give you a really bad time and potentially kill you. So, I mean, the general rule of thumb is that you never eat a mushroom that you've found unless you can positively identify it. What that means is that you're not just saying, well, it's not that, and it's not that, so it must be this. What you're saying is, I know for a fact that it's this.

[00:41:28] Jonathan Wolf: That's a high bar for most people listening to this, just wandering into their local park and seeing a mushroom.

[00:41:33] Merlin Sheldrake: But there are lots of ways to learn about, you know, what mushrooms are which, just like you can learn about what trees are which, or what birds are which, and it's actually a really exciting thing for, for many people to do, and there's lots of great resources online for those who want to learn more.

So I wouldn't discourage anyone from doing that. It's not like you need to become like, the expert who knows all the mushrooms overnight. 

[00:41:52] Tim Spector: I think there are about 300 edible types of mushroom. I heard I read somewhere and, but about 30 are cultivated and they're the ones you'd see in the shops. So up to 30, I guess is the, is the most you're going to see in this country.

[00:42:09] Jonathan Wolf: And most of us aren't going to see 30. They're maybe going to see a few. So that brings me back to the question at the beginning about, you know, dried mushrooms and, you know, are they still good for your health or does it need to be fresh in the way that I think you talk about a lot of other plants, you say, if they just sit out there for months, there's not much left in them.

[00:42:26] Tim Spector: I was surprised when I was reading this, that there are studies looking at the nutritional content of dried mushrooms. And I think a lot of this is done on shiitake mushrooms, but porcini as well, which the Italians often store dried. And they are just as nutritious, they've looked at the chemical composition and super healthy. And some people think they have more taste when they're rehydrated, you have to add water back into them, usually warm water. 

And so they seem to be very very healthy. So it's a bit like our stories about canned tomatoes or beans. Some of these things which you might think are not healthy because they're dried, you know, are actually still really good for you. And I think it shouldn't stop people eating mushrooms out of season by eating these dried ones. I think that's the message. 

[00:43:18] Merlin Sheldrake: Although you should find a reputable source because it's sometimes when dried mushrooms are imported you can't tell by looking at the fragments of dried mushrooms that you can't confirm just visually that it's the species it says it's, and there are cases of contamination or the wrong kind of mushroom ending up in your bag of dried mushrooms.

[00:43:34] Jonathan Wolf: So you're not really getting the variety that you want or the diversity. They're just giving you a bunch of..

[00:43:41] Merlin Sheldrake: Or there are ones cheaper thrown in with the ones you want and those might not be the ones you want to be eating.

[00:43:47] Tim Spector: So reputable source, but button mushrooms are the sort of common ones in the UK and they're often the cheapest and they're cultivated in large amounts. And although they look fairly dull compared to some of the exotic ones you see, I think they've still got plenty of nutrients in them.

[00:44:02] Jonathan Wolf: Is that right? Because they sort of look like the white bread of mushrooms, but you're telling me that actually they still, I feel like they can't have any nutritional value whatsoever, but you're telling me that actually I'm being unfair? 

[00:44:14] Tim Spector: I think you are yes. Certainly there may be better ones in my life, but you might be, you'll be generally paying more for the better ones.

But Merlin probably knows the differences between all of the varieties, but I still think there's no such thing as a bad mushroom. I think that's my point.

[00:44:29] Merlin Sheldrake: I'd agree with that. I'd agree with that. I personally think there are ones that taste a lot better and more and more available, actually, like oyster mushrooms or shiitake mushrooms, which I would always choose over a button mushroom.

I would agree that there's no such thing as a bad edible mushroom. But for those that don't like, or have not liked as a child, for example, button mushrooms, there may well be mushrooms out there that you do like, because there's quite a range of flavors and textures. 

[00:44:53] Jonathan Wolf: That's a bit like saying, so you can't give up on all mushrooms because you had a bad one.

A bit like saying you're giving up on all plants because you don't like artichokes or something that you'd be like, well, that's ridiculous. Like try a tomato. That's fascinating. 

Presumably Tim, because we talk a lot with Sarah about this idea of like the food matrix and complexity. Am I right in suspecting that a ground powdered mushroom is not likely to be as good as one of these dried but still sort of whole mushroom?

[00:45:24] Tim Spector: I think it depends how much it's been crushed if you like. So I'd like to see something that, you know, still resembles a mushroom in some way. So it's not a fine chemical powder and hasn't been reduced to those few chemicals we've talked about. It still has some of the complexity of all the things going in there, it hasn't been fiddled with too much.

But if we take, you know, just pure fast drying a whole mushroom, getting rid of all that water, and then, if you, as long as you grind it up and it's not too fine a dust, I think you're still getting most of those components. Because there are some studies showing that actually the cell walls of these fungi can have some benefits as well on health. And that was, I thought that was really interesting on the immune system. So you don't want to get rid of those. You still want to keep some of that structure. 

[00:46:14] Jonathan Wolf: So I think the story we always keep coming back to is, yeah, which is like you extract a few chemicals as people do and they want to make famous and you lose like the 9,000 other that are actually contributing to the, to the overall…

[00:46:25] Tim Spector: You lose the fiber, the structure and things that you're throwing away most of the good stuff.

[00:46:29] Merlin Sheldrake: But I'd also add that there are situations when you're taking a medicinal mushroom, for example, where you might want to concentrate it because you simply wouldn't get enough of those active fractions. If you, I mean, it would take, you'd have to eat so many mushrooms to get those, those active fractions that, that you might never get to that point.

So, I think there are cases where you might want to take an extract alongside your diet of whole mushrooms. 

[00:46:55] Jonathan Wolf: That makes lots of sense. This question came up a lot with people emailing in to us. How often should people be eating mushrooms? 

[00:47:05] Tim Spector: I would say try and get some mushrooms in every day if you can. And if, you know, at least three times a week. 

Most of the studies done for preventing cancer, et cetera, have done at least two cupfuls a day. So I think if you're really trying to make a big difference to your health, the more you get, the better and try and vary the species as well.

I think that's the other thing, cause we don't know yet what the particular advantages are. So as for plants, diversity, I think is, is going to turn out to be key. So this is something, you know, this is a very new field, but. Going for a diverse range of mushrooms, try to pick some new ones, you know, even if it's small amounts.

There are these mushroom teas and mushroom coffees, generally have very small amounts of actual mushroom in them. So don't be fooled into thinking that's really the same as having a full mushroom meal. 

[00:48:03] Jonathan Wolf: Before wewrap up, I'd like to ask you both this sort of final question. What's your favorite way of eating mushrooms and what mushrooms would be in there? 

[00:48:14] Tim Spector: I love a creamy mushroom tagliatelle using if I can get three different types of mushroom and I fry them up, get rid of the water, add garlic and some creme fraiche, maybe with a bit of kefir just at the end to give it a bit more microbial time, mix it with my fresh pasta. That's one of my favorite meals.

[00:48:42] Jonathan Wolf: Sounds delicious. And what are the mushrooms? 

[00:48:45] Tim Spector: It's whatever I can get really you know, I don't think you should be too fussy. So I, you know, I like shiitake mushrooms, porcini, you know, the seps variety. But I always like trying something new. Actually that's, you know, so they've all got different textures and things and but I haven't found one I don't like yet. 

[00:49:08] Jonathan Wolf: Merlin? 

[00:49:09] Merlin Sheldrake: I often just saute them, just fry them lightly in a pan, get some of the water out and eat them like that, maybe on toast or just by themselves. 

But also I love making soups and a soup might, I'd probably have a miso base in the soup. I might add some kefir to give it some creaminess. And I throw in as many different species as I could get into the soup, and the way the flavors can meld together in a soup form is something I really enjoy. 

In terms of species of the cultivated varieties, the varieties you could buy at a shop to add a good selection all year round, shiitakes, enoki, which are kind of white tufts of mushrooms with thin slender, slender stalks. Maitake, I love. Oyster mushrooms are great and if they're talking about wild species, then it's whatever is around. But there are various favorites. I just was in France eating porcini, which were fantastic and mountains of chanterelles, which I also really enjoy.

[00:50:14] Jonathan Wolf: If someone's listening to this and now they're really interested in saying, Okay, like I can get a certain amount in the shops and maybe I can get some more that are dried, but I'm really excited about all these wild ones that don't even exist, but I don't want to poison myself. How could they get started?

[00:50:29] Merlin Sheldrake: There are great websites and field guides, books. Which field guide you get, which website you visit will depend on where in the world you are. So it's important to find somewhere that's talking about irrelevant fungi and there's a great app called iNaturalist, which is also a good resource.

[00:50:48] Jonathan Wolf: Brilliant. Well, we'll talk to Merlin to see if we can get a few of those links. We'll put them in the show notes. And I know you mentioned actually just beforehand that, like, in a country as big as the States, for example, like the West Coast mushrooms and the East Coast mushrooms are really quite different.

So you would need to have a different guide.

[00:51:02] Merlin Sheldrake: Well, there'll be common mushrooms, but they're quite different ecosystems. So you might be better off with a local guide, which has fewer species in it than the big one that has all of them in it might be an easy place to begin.

[00:51:15] Jonathan Wolf: Brilliant. Thank you both very much. Merlin, I would like to try and do a quick summary and both you and Tim, please correct me if I've got any of this wrong? 

So we started off by just saying like, what is fungi? And amazingly it is a kingdom, which I love because it's not a word that we use very often. It's a kingdom of life. So it's as big as plants or animals, but it's it’s own thing. And it turns out it's lived, I think you said, for 500 million years, like in this life with plants where they've grown together and where, until we invented these modern agricultural chemicals over the last 100 years, it was sort of essential for feeding the plants that we all ate.

We've done a lot of damage to fungi with modern agriculture probably without really being aware of it originally. And this is likely to affect the plants we eat. So historically, the plants we ate would have been in these deep relationships with the fungi. And there would have been all these chemicals. Now we sort of feed them with these fertilizers. They're sort of much simpler as a result. And we talked about this, have been a little bit like sort of ultra processed food for plants, which we now know is not very good for people.  

Soil, therefore, historically absolutely full of life and today in a lot of the places where we are doing this intensive agriculture, there's a lot less of it. So there has been this sort of profound breakdown. 

Why does this matter? It matters because we think this affects the food that we eat as well as affecting the ecosystem around us. 

We then talked quite a lot about mushrooms, which I discovered are like the fruit of the fungi. Firstly, talking about medicine. And there's lots of places in which it's been investigated. It sounds as though around areas of mental health, Tim was quite skeptical about ET supplements, which are not a way to get into a movie, but apparently are the latest rage. But I think Tim, you said once again, you're very skeptical about something which is one chemical that's been extracted from these mushrooms and therefore leaving behind, you know, maybe hundreds or thousands of others.

And then we talked about mushrooms for eating. Both of you are incredibly positive, starting off with them tasting great, and therefore this to just be part of what we do. But also because they have all of these complex chemicals and for the same reasons that fungi extract all of these chemicals that plants can't, there's a high chance that we're going to access a set of chemicals that are probably not in our regular diet. So again, creating more diversity, which is something that we talk about a lot on, on these podcasts. 

Often better if slightly cooked. Which is the reverse sometimes of what we hear. It makes me pleased because I definitely prefer them that way. 

Even the humble button mushroom is just fine. And that I should not have been so prejudiced. Though I heard Merlin definitely say oyster or shiitake were probably his preferences in taste. But above all, there's no such thing as a bad mushroom. And really what you should be looking for is just like with plants, like diversity of them, trying different mushrooms. 

There are a limited number that are cultivated. I think you said there are about 30. I think I'd be lucky to find more than four in my local grocery store. So there's an issue about access, but the good news is actually dried mushrooms might be even better than fresh. So there is a way to do that. 

If you really want to go and access all the others then you're going to have to figure out how to do it for yourself. And we'll put some links in the show notes for those of you who are interested. But do be aware that some of them are poisonous, so you need to make sure you really know what you're doing. 

[00:54:56] Merlin Sheldrake: And also if everyone goes out and picks the mushrooms in their parks and in the surrounding countryside there won't be many mushrooms left, so foraging isn't really a sustainable way to feed a population at the moment.

So if you were going to go out and look for mushrooms, if you found some edible mushrooms that you were convinced were edible mushrooms, you knew were edible mushrooms, you might take a few of them to eat and leave most of them behind. 

[00:55:23] Jonathan Wolf: Brilliant! Thank you both very much once again, I started but I'm going to finish at the same time saying you have to look at the photos in this book.

I think they will really blow your mind in the same way for me as like first listening to Tim talking about the microbiome being inside us and how much that shapes you. I'm definitely not going to look at a plant in the same way as I did before, you realize that there's something really magical going on sort of under the soil. So I couldn't recommend it more. 

Merlin, thank you so much for coming in. 

[00:55:54] Merlin Sheldrake: Oh, it's been a pleasure. Thanks for having me. 

[00:55:55] Jonathan Wolf: Tim, as always, thank you so much for guiding us through this. 

[00:55:59] Tim Spector: It's been fun. 

[00:56:00] Jonathan Wolf: Thank you, Merlin and Tim, for joining me on ZOE Science & Nutrition today. It's been fascinating to hear about the incredible impact that fungi have on our planet — and can have on our health.

Now, if after listening to this, you're hungry for more science-backed nutrition and health insights, why not download our brand new guide, which captures 10 of the most impactful discoveries from the podcast so far. You can download it for free by going to zoe.com/podcast, and there you can also learn more about ZOE.

You'll also find the link in the show notes. As always, I'm your host, Jonathan Wolf. ZOE Science & Nutrition is produced by Yella Hewings-Martin, Richard Willan, and Tilly Fulford. See you next time.