Feel Better, Live More with Dr Rangan Chatterjee - Why Allergies Are On The Rise with Professor Theresa MacPhail #374

Episode Date: June 27, 2023

Pollen counts are rising and more of us are experiencing hay fever symptoms than ever before. From airborne allergens to the food on our plates or the chemicals and plants that touch our skin, around 40% of the global population has some form of allergic disease. By 2030, today’s guest reveals, 50% of us will be affected. Professor Theresa MacPhail is a medical anthropologist and writer, who made it her life’s work to understand more about allergy after her father died following a bee sting. Her book Allergic: How Our Immune System Reacts To A Changing World, is a detailed, enlightening look at the history of allergies and their growth in line with the industrial revolution. Why are allergies on the rise? Why is it that 200 years ago allergies barely existed, yet today they are in our pets and farm animals? We talk about what actually happens to cause the release of histamine - which is responsible for many of our allergic symptoms. Theresa also covers the main historical theories as to the cause of allergies from the ‘hygiene hypothesis’ to the ‘farmhouse effect’ and the ‘old friends theory’. What we do know is that allergies occur in the interaction between humans and our environment. Our environment has changed so much over the past 200 years and our immune systems simply cannot keep up. Theresa explains the body’s three main barriers to infection and allergy – our skin, respiratory system and gut. When these barriers are damaged, they become more porous and can let unwanted molecules into our bodies – causing infection, inflammation, or allergy. And what’s damaging them is things like air pollution, diesel fumes, chemicals, antibiotics, to name just a few. We cover the practical steps we can take to mitigate allergies but there are much wider societal issues that need addressing as well. Theresa explains that we are part of a bigger ecosystem - our bodies are continually making decisions on what they can tolerate and what they can’t. We can try our best to build up our own barriers to tolerate more of the modern environment but the uncomfortable truth is that we collectively have a lot more to do to protect each other and the natural world. This is a deep dive into a very important topic. My hope is that anyone suffering from allergies will feel seen, and anyone lucky enough not to, will gain more empathy and understanding. I hope you enjoy listening. *Please note that this conversation refers to studies on mice. Support the podcast and enjoy Ad-Free episodes. Try on Apple Podcasts https://apple.co/feelbetterlivemore. For other podcast platforms go to https://fblm.supercast.com. Thanks to our sponsors: https://www.calm.com/livemore https://www.vivobarefoot.com/livemore https://www.drinkag1.com/livemore Show notes https://drchatterjee.com/374 DISCLAIMER: The content in the podcast and on this webpage is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare provider. Never disregard professional medical advice or delay in seeking it because of something on the podcast or on my website.

30 to 40% of the global population have some form of allergic disease. Yeah, that's correct. But all the experts I spoke to said it's easily going to be 50% in the next decade. So as countries move into the middle class and upper class, they tend to get more disease. So it really is the richer you get, the more problems you have. Hey guys, how you doing? Hope you're having a good week so far. My name is Dr. Rangan Chatterjee, and this is my podcast, Feel Better, Live More. This summer is already proving a tricky one for people who suffer with hay fever. Pollen counts are rising and more of us are experiencing

symptoms than ever before. But it's not just pollen. From airborne allergens to the food on our plates or the chemicals and plants that touch our skin, around 40% of the global population has some form of allergic disease. And this week's podcast guest reveals that by 2030, form of allergic disease, and this week's podcast guest reveals that by 2030, that number will be 50%. Theresa McPhail is a medical anthropologist and writer who made it her life's work to understand more about allergy after her father died following a bee sting. Her book, Allergic, How Our Immune System Reacts to a Changing World, is a detailed, enlightening look at the history of allergies and their growth in line with the Industrial Revolution. Why are allergies on the rise?

What's making us more susceptible? And what can we actually do about it? Why is it that 200 years ago, allergies barely existed, yet today we're even seeing them in our pets and farm animals. Well, these are some of the questions we try to address in this week's conversation. Now, Teresa starts off talking about our immune systems and explains what actually happens to cause the release of a chemical called histamine, which is responsible for many of our allergic symptoms. She also covers the main historical theories as to the cause of allergies,

from the hygiene hypothesis to the farmhouse effect and the old friends theory. Each one offers us a potential part of the explanation, but none of them in isolation are able to explain at all. What we do know is that allergies occur in the interaction between humans and our environment. And our environment has changed so much over the past 200 years that our immune systems simply cannot keep up. Teresa explains that the body has three main barriers to infection and allergy. Our skin, our respiratory system, and our guts. When these barriers are damaged, they become more porous and can allow unwanted molecules into our bodies,

causing infection, inflammation, or allergy. And what's damaging these barriers is modern life. And what's damaging these barriers is modern life. Things like air pollution, diesel fumes, chemicals, antibiotics, to name just a few. So what can we actually do to mitigate this? Well, of course, we try our best in this conversation to cover the practical steps we can all take. But it's not just an individualized approach that we need. There are much wider societal issues that need addressing

as well. You see, talking with Teresa, what shone through most was the fact that we are all part of a much bigger ecosystem. We're basically in constant conversation with the world around us. Our bodies are continually making decisions on what they can tolerate and what they can't. Yes, on an individual level, we can all try our best to build up our own barriers so that we can tolerate more of the modern environment. But the uncomfortable truth is that we all collectively have a lot more to do to protect each other and the natural world. I think this was a wonderful, thorough, deep dive conversation into a very important topic. My hope is that anyone suffering from allergies will feel seen and anyone lucky enough to not will gain more empathy and understanding. I hope you enjoy listening.

I hope you enjoy listening. 30 to 40% of the global population have some form of allergic disease. Yeah, that's correct. What's going on? Oh my God, what's going on? So it's 30 to 40% now, but all the experts I spoke to said it's easily going to be 50% in the next decade. So we're just going to continue seeing a rise. And partially that's because it tends to track with socioeconomic status.

So as countries move into the middle class and upper class, they tend to get more allergic disease. So it really is the richer you get, the more problems you have. is the richer you get, the more problems you have. So as some countries are stabilizing, so the United States, the UK, there's constant rates, but in places like India and China, they're just playing catch up. So their numbers are growing exponentially. Yeah. 50% of the world's population in the next decade are going to have some form of allergic problem, right? And for me, when I think about allergies, when I think about this beautiful book that you've written, you've done a really deep dive into the history, what we know, what we don't know.

But it strikes me as though the topic of allergies, the rising rates of allergies, really says something quite profound about us as humans and us as humans and our ability to live in harmony or disharmony with our environment. Yes, absolutely. I mean, one of the fascinating things is the immune system is so old. So evolutionarily speaking, it's one of the first biological systems to develop. So mast cells, which are one of the main components of the immune system, they're about 500 million years old. So organisms, mammals developed an immune system to cope with their environment. So we've co-evolved with the things in our environment for literally millions of years. And within the past 200 years, we've changed

things to the extent that that old system, so the system that we have to cope with our environment hasn't kept up with the changes that we've made to our environment. So I like to say that it's almost as if we're running Windows 95 in a 2023 world where we have to run all of these apps and there's no possibility for an upgrade because your immune system, it's fairly fast evolutionarily speaking, but it's not as fast as the changes that we're making. Yeah. Mass cells being 500 million years old. That's right. That's quite something.

I mean, I guess we should explain at this point what a mass cell is. You've also mentioned the immune system in relation to the topic of allergies. So I wonder if we could maybe at this point just go back to basics and go, what's the relationship between the immune system and allergies? And then maybe unpick the immune system a little bit and explain innate, adaptive, what a mast cell is. Because I think that'll be really useful right at the top. Yeah, yeah, absolutely. are basically your immune system is two systems working side by side and they overlap in their function, but your innate system is older. So that is mast cells and bacephiles. So white blood cells who are the first line of defense, basically. And like I said, the 500

million years we think for mast cells. So it developed first and it's called innate because it's online from the time of your birth. And it's basically a system that responds pretty much similarly to everything. So it's there if something is entering us that is harmful or otherwise shouldn't be there, it clicks on and either sends out things like macrophages or something to like eat whatever is in us that shouldn't be there, to rip it apart, to get rid of it, to consume it, to eject it. rip it apart to get rid of it, to consume it, to eject it. And that is always online. The adaptive immune system is newer, so to speak. So it evolved later. And that is the system that remembers things. So that is, it's called adaptive because it adapts to whatever situation that it's dealing with. So those are the antibodies that will remember,

say, the SARS coronavirus. So it remembers a part of that, takes a snapshot of it, and then creates cells specifically matched to that thing. And so when they come across it again, they remember it, so to speak, and can put into play a response much more quickly. So the more times that you see something, the more reactive those cells get. Yeah. So the innate immune system or the innate part of the immune system, something we're born with, it's very, very old. It's non-specific. I think that's what we often say when we're talking to patients is, you know, yeah, it has a few tools, has a few ways of dealing with things. And as you say, it uses things like macrophages and mast cells, which of course are really important for allergies.

I think natural killer cells also are part of the innate immune system. And these things, I think people, you know, I think it's useful for people to understand that you're born with it. So I guess as a kid or as a, I don't know, let's say you're four weeks old and you're exposed to a bug, it's likely that your innate immune system is going to be the one that kicks in. Whereas it's this adaptive one is, I guess what gets tuned up through life as well, through our exposures, doesn't it? And in terms of the adaptive immune system and allergies, what's the relationship? Because mast cells are behind a lot of the

symptoms and allergies, but that's from your innate immune system. Yet often in the book, you're talking about the adaptive immune system in relation to allergies. So can you help tie that together for us? Sure. I mean, I should say that the innate system is good for most things. So the innate system will still kick in in your adulthood when you're exposed to something like a virus. And so the adaptive system kicks in if whatever you've come into contact with has escaped the innate system. So usually, like sitting here right now, our innate systems are just keeping us healthy and fine. So it's a situation where something's been able to evade the innate system and then the adaptive system kicks in, so to speak. So it's kind of like the

secondary mechanism that kicks in. And that is the one that is driving some of the allergic reactions via the antibodies. So there are five different antibodies that your body makes and they all have different jobs, so to speak. And the one that we're most interested in with allergies is called IgE. And that is the one that's behind most allergic reactions, though not all. It's tricky because there are some allergies that are not mediated by IgE. So the definition of what an allergy is can get really tricky really fast, especially if you're tying it to that IgE. Like my father died of a bee sting, but technically speaking, allergy to bee venom is not IgE mediated. It's the innate system. So those mast cells are firing instead. So it gets really tricky really fast when you dive into it. Yeah, that's something you made, I think, really clear towards the start of the book, that a lot of these different esteemed allergy experts

have kind of different ways of looking at allergies, different definitions. Right. And I think that's a theme that comes through the book very nicely is that this is a complex issue. There's no easy fix. There's no easy answer here. There's a combination of different factors, which I think is useful to keep in mind because we are living in a culture now where we want quick fixes and quick answers and what's going to get rid of my allergies. We're definitely going to get to treatments later on in this conversation, but I think it's really important to understand what these allergies are. Now, we've mentioned how prevalent they are. In the next 10 years, half of us are going to have some form of allergy. Allergies exist on a continuum. right some people it's unpleasant at certain times of year

yet other people like your father end up dying from allergies right so i wonder if you could if you're open to it explain what happened to your dad and also then relate that to this continuum and maybe to the innate and adaptive system if you feel it's appropriate. Sure. So I guess what I'll start with is the basic mechanism. So I mentioned these IgE antibodies and a lot of us have heard the metaphor that our immune cells, our antibodies, or our T cells specifically, are the policemen of the body. So T cells are just a class of white blood cells that circulate throughout the body looking for things that shouldn't be there or suspicious activity, I guess you could say. And so in that way, they are kind of like policemen patrolling a neighborhood. But what they do is they'll come

across something like a virus or an oak pollen. And if they decide it shouldn't be there, what will happen is they'll take a snapshot or almost like a protein signature fingerprint of that thing. But then they take it to another class of cells called B cells, another type of white blood cell. I like to think of them as the store managers or the nightclub managers on the street. And so it's basically, hey, this neighborhood is under threat. Here's a picture of the perp. Please be on the lookout. And then the B cells are producing the antibodies. And so I like to think of IgGE as a bouncer, that they're there at the door to these neighborhoods, these different stores, nightclubs, and their job is to decide who gets to come in

and who has to stay out. But if you think of it this way, every bouncer or every security guard has only one picture. So they're looking for one thing. And so at any entrance, you're going to have maybe, depending on what you've been in contact with, that your body has remembered that it needs to take care of, you'll have 50, 100 bouncers, and they're all looking for their one thing. But the problem is, like, say the description is, oh, this person is 5'7", But the problem is, like, say the description is, oh, this person is 5'7", dark hair, light eyes. A lot of things are going to look like that, which is why often we'll get cross reactivity. So you might be allergic to one tree nut, but you're actually going to probably be allergic to more than one because they're all in the same family. So it's kind of mistaken identity.

Yes. Yeah. And then they turn on the mechanism of let's get this out of here. So it turns into a bit of a rumble. And I guess the nightclub turns into a very unpleasant experience because then they're signaling to other cells, hey, we've got a problem. And it starts that system in play, which is driven by histamine. So what happened with my father is partly driven by just his innate cells. So mast cells are basically the drivers, the conductors, if you will, of this whole orchestra of things that happen. And they emit histamine. So it's just a chemical compound that your cells use to signal other cells when they are damaged or stressed. And they are signaling to cells in their neighborhood that there's a potential threat that something is happening. And so the cells that receive the histamine signal will send

out histamine as well. So it's a bit like those nuclear reactions, the ping pong. We've all seen the video of someone throwing a ping pong into the mousetrap ping pong room. And before you know it, the whole room is just exploding. That's kind of what histamine does. So the histamine is the ping pong ball and it just sets off everything around it. And so what histamine ends up doing in the body is it produces all of our symptoms fairly. Yeah, most of our symptoms. So histamine will drive your mucus production, which is why we get congested and runny nose and eyes. It can swell tissues.

So it causes swelling in areas. In my dad's case, he was stung in the neck. So it swelled his neck tissue, which was not great for breathing. But it also, histamine can constrict your muscles around your lungs, which is what happens during an asthma attack. So when the muscles tighten, it gets harder to take a full breath of air. So that's happening. But then histamine is also dilating your blood vessels. And there's a good reason for that because it makes it more permeable. So all of those first responders of the immune system can get somewhere quickly. But the other effect of that is it crashes your blood pressure.

So as your blood vessels dilate, it just makes it harder to get blood to your heart. So it can send people into a cardiac event, which is what happens a lot of the time during anaphylaxis if you don't stop that histamine reaction. Yeah. And your dad, I believe, died within 30 minutes of that sting. That's normal. So if you don't control a severe reaction and you're going into an anaphylactic reaction, you have about 30 minutes before someone dies. to an anaphylactic reaction, you have about 30 minutes before someone dies. Okay. Now let's just pause there because I want this to be an empowering conversation. I don't want to overly scare people. So, you know, if we're saying that almost half of us are going to be allergic to something, you have outlined, and thank you for sharing the case of your dad's,

you have outlined, and thank you for sharing the case of your dad's, a very severe episode of allergy, right? But most people, I think, are not going to experience it to the same level. Correct. So, you know, because a lot of people will recognize some of those symptoms, swelling, itchiness, maybe a bit of tightness. And there's other things with your dad's story that I think are really, really interesting and insightful when we think about the history of allergy and the history of treatment in that, if I remember rightly from the book, his girlfriend at the time drove him to a pharmacist or a drugstore. And an EpiPen was there, I believe, but it wasn't administered. Is that right? They had adrenaline on hand because, of course, you know, they're a pharmacy. But the laws at the time, pharmacists weren't allowed to dole out the medicine on their own

without a prescription. He couldn't do anything. His hands were tied. So he couldn't give the adrenaline. And that's possibly because, I mean, of course, like say it looks similar to a heart attack at the end stages when you're going into the cardiac event. And if you give someone who's having a heart attack adrenaline, that's the exact wrong thing to do. And you're going to make it worse. And so he was just, he thought he knew what was happening. I mean, it was obvious that he had been stung, but just legally, he was afraid to give my dad the treatment, but also at the time. So this was 1996. And it's important to note that date because in the United States, It's important to note that date because in the United States, the explosion of food allergies really only started in the 1990s.

So now I think a lot more people are prepared and there have been laws put in place that people have to have access to adrenaline. So EpiPens are ubiquitous. And so you would be able to find one more quickly. But then there weren't any mandates. So if you were an ambulance company, you didn't necessarily have to have an EpiPen available in your cab. So in 1996, ambulances in America would not necessarily have an EpiPen there. Right, right. I mean, that is, I guess that really speaks to this whole issue, which is how quickly allergies have exploded and how just, what's that? 30-ish years ago, under 30 years ago,

and ambulance maybe would not carry an EpiPen or adrenaline. Right. Yeah. It would have, I mean, perhaps some people were definitely carrying it. So there were people with severe allergies that would have had a prescription for something like an EpiPen, but it wouldn't have been to the extent. So prescriptions for EpiPen have just quadrupled over the span of 30 years. So you're seeing many more people. So I think the last statistic I saw was about 5 million Americans have a prescription for an EpiPen. It's interesting because that is not who fills them. So about 85% of people who are given a prescription fill it, and some people just never even fill the prescription.

people just never even fill the prescription. Yeah. Do you ever reflect and think, had that pharmacist given your dad an EpiPen, what might have happened? It probably would have saved his life. Or if that ambulance company had had the access to the adrenaline, but they didn't. So all they could do was stabilize him. So they were trying to keep his heart stabilized. They were giving him chest compression. Once he started into the cardiac event, they were trying to stabilize his vitals. But after that, when you've reached that point, it's very hard to stabilize your system, especially outside of the hospital. So the survival rates, if you can get to a hospital within 30 minutes are quite good, but it's, it's that key time where you need to halt the, the reaction in time. EpiPens do that wonderfully, which is why we have mandated that they be in

schools in the U S so every grade school and middle school and high school has to have a pen on hand. And we have mandated, although the United States is interesting, it's state by state. So some states have mandated that all ambulances have to have them, but there are still states where they leave it up to the discretion of whoever is running the service. Yeah. I mean, there's some wider cultural and ethical issues, I think, around allergies as a whole, which you do talk about in the book and we'll hopefully talk about later on today. But, you know, it's really, really interesting. I mean, I know you start

the book with that story about your dad. It's clearly a big driver for you to go and explore this topic. You seem very calm about it now. Was there frustration and anger for a while that an EpiPen was not given? It was not administered when it was actually there? No, it's strange because I was so young. I was only 24 at the time. And it was just such a shock that to be honest, I didn't really think about those things until later, until I started researching the book. I never really questioned why there wasn't something on hand. It was just such a shocking thing to get that phone call that he had passed away. And otherwise, I mean, he had a few underlying health issues, which is obviously part of this story. So he had a little bit of heart issue anyway. So obviously if you have underlying issues and then you go into anaphylaxis,

it's much harder. I mean, so I basically just thought about that and I was terrified of bees just thought about that. And I was terrified of bees for the longest time. Still am not. I mean, I love that they're pollinators and I support bees, but at the same time, I do not like to be in the vicinity of a bee. Yeah, understandably. So let's just make it super practical then for someone who's hearing this or watching and thinking, okay, well, I've had a bee sting before and had a bit of a reaction, but you know, I was okay. And then they're hearing the story about your father dying within 30 minutes of a bee sting. Have you got anything to say that's going to help them feel better? Because what I don't want is people on the back of this to be panicked about everything in life go wow allergies on the rise I could die at any moment right and so I think we need to be just

mindful of that yeah most people are not going to have that reaction to a bee sting it's so rare it's so rare it is 0.000016 so the population population will have that reaction to bee venom specific or wasp venom. So if you're stung by a bee or a wasp, your chances of dying are so slim. I think in the last five years, it was 60 people total. Globally or in America? I think just in America. It's a little bit bigger globally simply because a lot of people don't have access to things like EpiPens everywhere. They have to be stored at a constant temperature. So in the more humid and hot zones, there are a little bit more stings. And so there are a little bit more deadly reactions, but still on the grand scheme of things, it's nothing compared to something like food allergies,

which is a much higher percentage of people are going to have a potentially serious reaction. Yeah. And just what those statistics in context, I don't have the exact statistics to hand, but I imagine your risk of dying in a car crash is probably much higher. Miles. Yeah. Just to really bring some balance to this conversation. To be fair, I think your odds of slipping and falling in the bathtub and dying are higher. Yes. Okay. So these are rare things. Obviously, it did happen to your dad. Right. You mentioned food allergies rapidly increasing in the 90s. Yes. And I think food allergies is something that many people are familiar with. I think if you talk to any school caterer these

days, they will tell you, you know, 30, 40 years ago, we might have had one person with an allergy or an intolerance. And maybe at some point we should talk about the difference between the two. Yes, absolutely. But these days, it's not uncommon for school catering companies, school chefs to have to make quite a lot of different meals for the same class. Yes, that's right. Now, I know you're a medical anthropologist. So before we get into food allergies, the context here is that there are rapidly increasing rates of allergies. And that can be food allergies. It can be allergies to things that we inhale.

Right. It can be things on our skin. Of course, those are the three big sources. But what do we know about allergies in indigenous populations? So if we went to a hunter-gatherer tribe, let's say in Tanzania, right? Would we find allergies there? Do we find anyone dying from a bee sting? Or is there something about the way that they are living, which means that's not happening. Just taking a quick break to give a shout out to AG1, one of the sponsors of today's show. Now, if you're looking for something at this time of year to kickstart your health, I'd highly recommend that you consider AG1. AG1 has been in my own life for over five years now. It's a science-driven daily health drink with over 70 essential nutrients

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So if you go somewhere where they're still living closer to the land, so they're farming directly like smaller farm villages or smaller hunter-gatherer tribes, then yeah, you're going to have a lower level of allergic disease. But interestingly enough, we're finding new data out of places like a great example is Uganda, where they expected to find lower rates of allergy out in the outside of the city center. So going out into the smaller villages. And what they found was that people are developing hay fever and asthma out in the rural regions of countries where we would have traditionally thought that they would have been fine.

So something is happening globally, which is really interesting. Do we know, and I know it's probably hard to get this kind of information. I know it's probably hard to get this kind of information. That sounds like a modern Ugandan population living out, you know, away from cities are now starting to develop allergies. Do we know if that was happening three, 400 years ago? No, I mean, we do know. And the answer is no. So traditional hunter-gatherer tribes,

traditional indigenous tribes, traditional communities living away from industrialized cities, it looks so they had minimal allergies. Minimal. Always we had the capacity. So if you look back at the history and you look at historical records or just the way people were writing, we do know that bee stings and wasp stings were always capable of producing what happened to my father. So there's a famous Egyptian king that one of the inscriptions said that he was felled by a wasp. And so we think, well, that sounds like anaphylaxis. So we know that we had that. And we also know that that evolution there, And we also know that that evolution there, why would we conserve evolutionarily speaking DNA that prones us to this kind of response, right?

So anaphylaxis means backwards defense. So it's the immune system turning against you basically, but accidentally it's, it's killing you while trying to keep you alive. And so why would we conserve that? And they think it is exactly because of things like venomous insects and other venomous snakes that it might have given us an advantage back then. So the system was in place, but wasn't being triggered by something like bee pollen, or not bee pollen, just pollen in general. Yeah, there was something I read in your book about pollen rates are going to, what is it? Is it double by 2040? It was something like that. It was remarkable. And it's going to be more potent pollen. Correct. And that's all climate change.

I like to say that people who have allergies are the canaries in the coal mine of climate change effects on our biology. So I think a lot of us think of climate change as, oh, that's going to affect us 10, 20, 30 years down the road. And I'm always here to say, no, it's happening right now.

It's happening all around you. I was checking the pollen counts here and they're through the roof. They're through the roof everywhere. When you say hey, you mean since you've been in the UK? Yeah. Yeah. Just for fun. Like that's a weird hobby of mine. Wherever I go, I check the pollen count. a sufferer and you know I definitely want to cover the emotional distress that people with allergies often feel I bet you someone who who has a severe pollen allergy is also checking them regularly or looking at where they can go on holiday oh I'm not going to go there because of the pollen count so it stands to reason that you would do this but I think that also speaks to what you just said about the Ugandan population. If this is something that's happening

to the entirety of our environment, well, of course, no one's going to be immune. Even these communities where we hardly ever saw it, they're not going to be immune. And I'm sort of drawn to this wonderful quote you put in the book from H.W. Barber and G.H. Oriel, published in The Lancet in 1928. Allergy is beyond question the most important biological and medical problem that exists or ever has existed,

for it represents the pathology of the reaction of man and the lower animals to their environment, to the air they breathe, the physical agents such as light, heat, and coal to which they are exposed, the food they eat, and the various parasitic organisms which may invade them. And I love that quote because it kind of speaks to what you're saying about allergy sufferers being the canary in the coal mine. Something is going on globally. And if you are not a sufferer, you know, great, number one, good for you. That's amazing. But you may well go on in and about your life in oblivion. You may think, what is all this allergy stuff that's going on? You know, and that is very common for people who don't suffer to kind of downplay it. What is it that, you know, we often see this, and I say this with real sympathy and compassion,

but the older generation often will say, what is this? Yes. Right? When we were kids, there were no allergies. Now everyone's allergic to everything. Right. But as your book is showing, yeah, you're right. Now everyone is allergic to everything, or it Because your book is showing, yeah, you're right. Now everyone is allergic to everything

or it's certainly going that way, isn't it? Yeah, and it should concern all of us because it's that delicate balance. So we are part of an ecosystem and it's easy for us to ignore that. But allergy sufferers can never ignore that because they're in a constant conversation with the world around them. So I have changed my thinking about what my body is doing. So right now,

as we're sitting here discussing things, our bodies are in a conversation with the things around us without our knowledge. So you're right. If things are functioning well and you're not getting a negative response, you're oblivious to those conversations. Like think about how many things you came in contact with already today. Like, did you wash your face? Like, did you use a cleanser? Did you shampoo? Did you use dish soap on your glass? Like, so you're drinking from that glass, you know, your carpets emanating particles. Like it's just, it's constant. And our bodies are constantly having to make decisions about, well, are we going to tolerate this or not? And in someone who is tolerating it quite well, they can think nothing's happening, but something is happening.

And an allergic person is really aware of their surroundings and that conversation to a level that someone without allergies is not. I remember in my twenties, and again, you know, I was a practicing doctor at the time. So I was seeing many patients with allergies and, you know, I was a practicing doctor at the time, so I was seeing many patients with allergies, and you know, we had a pretty limited armory of treatments to give them, you know, it was pretty frustrating, and I do remember one of my best mates from university at the time, he was an IT professional, and I think he once had to take two weeks off work because of severe hay fever. Right. And that was one of the first times, you know, it's interesting, you know, as a doctor, you can see it with patients.

But when it's like one of your best mates who you're like, mate, what, you can't go to work for two weeks. Yeah, he goes, mate, I'm floored. I'm exhausted. I can barely open my eyes. I can't sleep. I'm itchy everywhere. And interestingly enough, he's doing very well now, but it can be pretty profound, can't it? It's not just a bit of hay fever. For some people, it's much more than that. Yeah. I think a lot of people think, oh, you're just sniffling a little. Like, what's the big deal? But it does affect your sleep quality. So all of that histamine production, if you're a little bit stuffy, you're not breathing properly, you're tossing and turning all night. If you've

got the itch, you're just constantly scratching. If you've got eczema, it is really an emotional toll after a while because you're just not feeling your best. So when I first started researching the book, I would want to talk to regular people that had allergies. And one of the most profound things is that people would say to me, why? You know, you want to sit down and have me talk about my hay fever? Like for what reason? And I said, because obviously I want to hear what it's like to live with that. And once they started, it was almost like being in a confessional booth because we've just become so used to, or it's become so normalized to downplay your own allergies. Like you don't talk about it, but even if it's causing you to lose sleep

or it's affecting your productivity or your focus, like children with allergies do worse in school because they have a harder time focusing because they don't sleep well. And so that it's just got these knock-on effects. But most of us have been trained like, well, don't bring that up. You know, it's not cancer. It's not heart disease. Like we could, well, it's not diabetes. Like,

why are we discussing this? But once you got someone talking about the effects on their life, it was quite shocking. I mean, they're spending a ton of money on treatments, constant treatments and trying new things. They're thinking about it. So they're thinking, oh, well, I can't go play soccer. Sorry, football. Because the pollen's quite high today. And so I'm going to avoid that. So I'm not going to go out with my friends. It's affecting everything in their lives, but they're just so used to internalizing it and they never quite feel their best. Yeah. And I think a lot of us just don't really understand what that's like to your set point. If you have respiratory allergies year round, which a lot of people do, or you have low

level food allergies and you're constantly anxious about coming into contact with your trigger, it's just emotionally exhausting. Yeah. It narrows your experience of life. It does. Yeah. Usually. Yeah. I mean, think about your best, most energetic day and how that feels and then imagine never feeling that way. Like someone with a constant chronic allergy allergy just kind of feels less good all the time. And they have almost given up hope for feeling the way a non-allergic person feels. So someone with severe eczema, which is one of the worst allergies in my opinion, because it's the hardest to treat, they kind of have just accepted their lot and they're thinking, well, I mean, I just

like to be normal. Like that's their goal. It's like, they don't even want to feel superior, like great. They just want to feel normal. And I think people don't really recognize how that feels for, if you don't have it, it's very hard to imagine, so to speak. habit, it's very hard to imagine, so to speak. I almost think this is going to sound insane. You know how when you're younger, you had, at least in my generation, you had to watch those terrible videos of car crashes when you were young so that you would know not to drive drunk or you would know not to speed. I almost feel like someone should be shown, like if you really think this isn't a big deal, you should have to watch a video

of an anaphylactic response. Because once you've seen it, you understand how terrible it is. But if you've never seen it, you think, oh God, this person's ruining my party. What do you mean I can't have peanut butter? What do you mean? They don't really understand what someone is afraid of or what someone is dealing with. Yeah, I guess a lot of the time allergies are invisible, aren't they?

I know eczema, I guess, depending on where it is on the body, it may be invisible or visible. But I guess the point I'm trying to get to is that it's not as obvious as a broken leg. Right. Right? So the guy with a broken leg gets sympathy. Can I help you? You know, what can I do to assist here? You know, do you want to sit down? Whatever it might be. But with the allergies, it's not quite the same. And I agree with you. Eczema is when you've seen patients or you've got it in your family,

you experience the itching, the discomfort, the inability to sleep, the constant scratching, the bleeding. And then I'm really struck to what, who's that eczema expert in the book you quote quite a lot? Oh, Dr. Peter Leo. Peter Leo, yeah. And, you know, in the section on treatments, he says the definition of an effective treatment relies almost wholly on the patient's perspective. It's fascinating, isn't it? Because actually, how can we as clinicians

determine if that is a successful treatment or not? Basically, by what we can see, it's about how does that patient feel? Maybe you can still see eczema, but if they're not feeling the pain and the discomforts, well, they might regard that as a successful treatment, right? well, they might regard that as a successful treatment, right? Yeah, exactly. So they might be feeling good enough that they're happy with whatever it is, but it can go the opposite too. Someone with the clinician's perspective will be like, well, your skin is clear and yet they're still not feeling well. So they're still getting a little bit of itch or they're still having discomfort. And from just a strictly objective perspective, you would say, oh, well, it cleared the rash.

The itch is lower. So what's this person's problem? But it really depends on the subjective experience of the person living in that body. And that's a really hard thing. I mean, it's always, as you know, in medicine, it's incredibly difficult to measure things like pain or itch or anything like that because it's fully subjective. And there's not many objective measures to that. So yeah, it can be quite difficult. Like someone with milder hay fever might not even take an antihistamine because they're just, oh, well, this is fine. But someone else might really be struggling with the same symptoms. And it really depends. But to go back to the sympathy, I mean, I think even other invisible things.

So say you've had a heart attack. There's something there that people can latch onto. Like it's life-threatening in a way that people understand. And so there's sympathy for that, even if you can't visibly see that someone's had a heart issue. But there is very little sympathy for someone with allergy because I think there's something about this idea

that it's not life-threatening that really makes people less likely to be sympathetic. Yeah. I think you touched on a really important point that allergy suffering is not just a mere inconvenience for the party organizer. I think we should talk about these wider cultural issues actually because there is a sort of ethical question then, isn't there, as to whose responsibility is it?

Right. So some people will say, for example, why should we have to change what we're serving at this party or on a plane, let's say, because one person may be suffering. Whereas that person may say, hold on a minute, you know, that could kill me potentially or cause me extreme discomfort. What are these kind of ethical issues do you think we have to navigate as a society? It's really difficult. So I think there was a shift in the last century anyway,

I think there was a shift in the last century anyway to thinking about people's medical problems as individual problems. So, you know, it's something with your biology that is dysfunctional. And so therefore it's a you problem. And so you take on the onus to fix it. And with allergies, you can't do that because the perfect solution to an allergy is to avoid all the triggers. So you don't come into contact with the thing that you're allergic to, but good luck if it's grass.

What are you gonna do? I mean, that pollen is everywhere. Or in the case of food, like, yes, it's the individual who's allergic to the nuts. But they can't be in charge of keeping themselves safe. That is a communal problem because they're in the situation of being in the restaurant, say. They can't be fully in charge of keeping themselves safe. they can't be fully in charge of keeping themselves safe. They've got to rely and trust that the people that they're interacting with take them seriously and take care in their food preparation. So it is a social problem and it's not their fault that they have

the allergy. It's our fault as a whole society. So we are making choices about how we're living in the world that is causing some of us to be more irritated. And so our immune systems aren't coping as well, but we're not causing the environmental problems that led to that individual problem. There's something going on that is causing us to be more irritated. That's not just skin irritation and gut irritation. That's just a kind of holistic irritation in relation to our environment. We're not in harmony with our environment anymore. We're being irritated by it. Or certainly the interaction of us with the environment is causing irritation. And you can take this beyond allergies, actually. We can say allergies are a societal problem,

right? But then let's take something like obesity or type 2 diabetes. You could argue the same case. You could argue that exposing people to this toxic, energy-laden food environment when we are literally wired to seek out food and seek out calories and store them when it is available, that's our evolutionary hardwiring. Is it an individual's fault at that point when they're getting obesity or type 2 diabetes? I mean, we like to say it is, and it's a willpower and all this kind of stuff. But the more you really delve into this, and of course, we can empower ourselves to make changes for sure. But we also have to recognize that it's a very problematic food environment. And if you took your lean, great, great grandparents and put them into this environment, you would find a lot

of them aren't remaining lean. A lot of them are succumbing because the environment is driving your behavior. So I think there is something quite uncomfortable for us all to think about because let's get into some of the causes of these allergies, right? Because I think that the next part then will become really quite relevant. But before we do that, let's just talk about some of the things you have changed that, let's just talk about some of the things you have changed in the way you're living your life since you wrote this book. I just think about my body in a different way. First of all, I understand that my cells are in conversation with all kinds of microbes, like microbiota that is inside me and on me and in the world. So I have tried to change my habits to kind of support the natural microbiota that's on my skin and in my gut. So I try to eat

more fruit and veg. I am terrible as most of us are. I read a statistic the other day that 90% of Americans don't get enough fiber. 90% what? That's most of us. And it's fruit and veg mostly. It's like cruciferous vegetables and eating skin on potatoes. And we just are not doing it enough. So I try to make those choices. So I try to eat something green every day or, and a lot more fruit and whole wheat. And I'm just trying to give my gut microbiome what it needs as well as what I need. So I think about them in that way. My skin, I think I have really become more aware of what I'm putting on it. So I tend to less is more. So I try to use more simple products with less ingredients and less often putting things on my skin.

I shower every other day to try to give that microbiome a chance to do its thing. I change my sheets less frequently. So every- Your bed sheets. Yeah, every other week, because for the same reason, you're tracking in normal bacteria and you're sleeping in it.

And that's kind of normalizing that bacteria on your skin. And of course you don't want that to get out of control. Like you can't go months without changing your sheets, but just giving it a little bit more of a foothold. Just trying to think about not just what makes me happy, but what makes the things that make me up happy because we're not fully human. And I'm well aware of that in a way that I think most of us aren't. I'm well aware of that in a way that I think most of us aren't. I'm constantly thinking about the organisms on me and in me that are helping me be me. Yeah. It's truly fascinating. You've spent years delving into the research on allergies, the history, the current treatments, where treatments are going.

Yet the practical things you've changed are things that we could all possibly start to do. We didn't really cover ultra-processed foods yet, but I think we need to talk about the microbiome and all the various hypotheses that exist as to why allergies are on the rise, because I think that will then inform why you've made these decisions. But a lot of these things I've become really aware of over the last five, 10 years since I started studying the microbiome and just realizing, you know, everything you put on your skin is getting absorbed. you know, everything you put on your skin is getting absorbed. And, you know, you see this marketing machine. I remember as a kid, right? I remember as a kid, teenage boy, you know, men's health had just, I think, launched around that time. And you're seeing these male physiques on the cover and you think, wow, you know, I'm quite skinny. That looks pretty cool.

I mean, you start buying it and you start to read all this stuff about, you need to moisturize, you need to exfoliate, you know, when they're trying to get men now into the beauty industry. And I remember maybe when I was 16 or 17, I'd buy this stuff. I'd go into Boots and I'd buy this stuff and think, yeah, I've got to do this every day. You've got to put cream on before you go to bed at night. And about 10 years ago, I thought, wait a minute, do I need to do anything? I stopped everything. I literally everything. And I think I've got pretty good skin. Right. And I don't use any products. Right. And again, you know, I do pay attention to my lifestyle, what I put in, you know, what I'm being exposed to for sure. But a lot of the things we consider normal are just pure marketing.

I mean, often, so I had more than one allergy expert say to me, if he could do an experiment where he forced people to live the way they lived in 1600, minus of course the plague and TB, to live the way they lived in 1600, minus, of course, the plague and TB, you know, not quite taking it that far, but just stripping away all of those modern things that we take for granted, that he would almost guarantee me that the rates of allergy would plummet. That if we simply stopped slathering ourselves in things, using harsh detergents to strip our skin. So a lot of the things we use are just, you know, devastating that microbiome. And eating differently and doing things outdoors more often. Not sitting on your dust mite infested couch watching Netflix for hours at a time,

that we just wouldn't have the same problem that we currently have. I mean, most of us don't realize one of the most shocking things for me was that, you know, the Environmental Protection Agency in the U.S. has 85,000 different chemicals on its Toxic Control Substances Act list. I mean, just think about that. And those are all, I mean, our chemical industry really took off post-World War II, which also tracks with the start of the explosion in asthma and hay fever in the U.S. So there's obviously a connection between all of the stuff we're making and coming into contact with that our bodies have never seen before. Like historically speaking, evolutionarily speaking, those 85,000 chemicals, I mean, some of them were natural and

existed, but a lot of them are man-made. Yeah. And it's hard to avoid this exposure because I've been reading a study on PubMed recently about commercial dishwasher detergent. Right. Right. So that's probably going on in many restaurants and cafes and actually the residue that's left then on the plates and the cups. Right. And then what are you kind of drinking from or eating from? And that can then negatively affect your microbiome. The problem with this whole area, though, is it gets very scary very, very quickly because it is a barrage of exposure to chemicals. And maybe one or two of these chemicals that are toxic, we could maybe have the resilience to cope with that. But this constant peppering. So my philosophy is very much

in my house where I can control things. I try my best to limit the exposure. Now, the problem is when you try and buy these better quality products that are cleaner and less toxic, they're more expensive. Of course they are. So then you've got this whole cost issue and we're not even started on air pollution yet. And people in lowest socioeconomic classes living near more air pollution, near roads, their rates of asthma and allergy are higher than others. You've covered all of this in your book. So it is a societal issue, isn't it? It really is. I mean, it really is. We can't because we're born into the world that we're born into. I mean, there's systems already at play. And so, yeah, if you're

happening to be born next to a bus depot, you don't really have a choice about the exposures you're getting. But what about, as you've outlined in your book, if you're born by cesarean versus vaginal delivery? Again, you don't make that choice. And of course, there are some very, very good reasons to have a cesarean section. I completely get that. But there is a consequence. There is. Because what they've found, what researchers have found is so our immune systems need to get trained in essence. So that adapted immune system that we were talking about, those cells need to be trained to recognize what's acceptable and what they can tolerate and what they can't. And that starts at birth. So when you travel through the vaginal canal, you're picking up your mother's natural, like our genital tract has its own microbiome.

So they're getting exposed to that as they're passing through the vaginal canal. If you're being delivered via C-section, you don't get that exposure to those bacteria. And it turns out that the order of bacteria that you are exposed to, so first you get the vaginal canal, then you get bacteria in mother's milk. So when you're breastfeeding, you get different things. And you're also getting, interestingly enough, breast milk has components that also feed bacteria. So you're getting seeded with bacteria, but then you're getting a source of food for not just the baby, but for the bacteria that you've been seeded with. And it turns out that that order is necessary for a healthy gut microbiome. And then why would it not be necessary, right? If we think about this on an evolutionary level,

like tens of thousands, hundreds of thousands of years, there is a way in which we come out into the world. And I think I read in your book that it starts off lactobacillus is what gets seeded initially. I think, I can't remember, that's exactly correct. And then it changes when what's coming through the breast milk. Now, always mindful of parental guilt when I'm having these conversations, because clearly if that is your child and they've got allergies now, you can hear this and start to beat yourself up. Of course.

We definitely don't want that. Right. In fact, what would you say to that? I would say that you didn't cause your child's allergies. I mean, it's so complex as we'll get into. I mean, that's just one part of the story. So sure, they didn't get the same microbiome starter pack, if you will, that other children get, but that's perfectly fine for a lot of children. Like they're not going to get allergies.

So it is such a combination of factors that it's almost a waste of time to try to figure out why your child has allergies. That's what I would tell people because they do become archaeologists of their own lives. Like when someone has a child that develops a moderate to severe allergy, they spend a lot of time going, what did I do? What did I do? Nothing. Nothing to cause this anyway. I mean, it's just such a complex series of events that led to your child developing allergy. And we really don't even understand why certain cells make the decision to react poorly. Yeah. That's something that comes through very clearly in your book is that we've got a lot of theories. There's a lot of science supporting certain theories, but no particular theory in isolation explains everything. There's no smoking gun. It's

multifactorial. The way I look at it is that if the immune system is a sort of, i don't know permeable barrier i guess then we've just overwhelmed it with yeah with a whole variety of different ways yes one could be over medicalizing some births one could be the overuse of antibiotics one could be the cleaning products that are used everywhere in every cafe you go in this they're just spraying this stuff on every table before you come so you can actually breathe it in as you're going, you know. And actually, when you learn what that is doing to our microbiomes, you're like, there must be another way. But that particular cafe, and this is the whole individual versus societal conflict that I think there is, I think there is, that individual cafe just wants a clean, non-greasy table for its customers. The quickest way to do that is to get a toxic spray, spray it there, and all the stuff that was spilt beforehand, all the grease on the last client's plate, that goes. So you've got a nice,

clean table for your new client, Okay. You keep it moving. You keep taking your money in. I get it. I'm not having to go at anyone, right? That's clearly what's going to happen. But if we expand that out over every cafe and every restaurant, and then you think what is in those sprays? What are we being exposed to? What are we picking up on our hands? The hands are then going into our mouth. If you are susceptible, and of course, some of us, as evident as by the fact that maybe 60 to 70% currently of the world's population do not have allergies, right? So that means that some of us, for whatever reason, have the ability to not react as of yet anyway. Yeah, exactly. We're coping better. So the people that don't have an allergy are just coping with that situation, but they're still in that situation.

And I would say there's a tipping point. So what an allergic reaction really is, is so your individual T cells, like say they, so theoretically speaking, if you're a scientist or a scientifically minded person, you've got a perfect control experience. So you've got the genetics are the same. You've got the environments the same, and you've got the exposures are the same. All our cells in our body should be exactly the same, which means we should be able to predict how they react. should be exactly the same, which means we should be able to predict how they react. So for someone allergic to peanuts, when those cells come into contact with the peanut, all things being considered, you would think two T cells meet this protein in the bloodstream and will make exactly the same decision, and they don't. So one will see that protein and go,

that's fine, tolerate, move along. And one will come across the exact same protein and go, that's fine. Tolerate, move along. And one will come across the exact same protein and say, nope, I've got to deal with you. This is terrible. And turn on the reaction. What an allergy is, is just the tipping point of more of their cells making that decision that it's not okay to stay than not. So in a person reacting to pollen, some of their cells aren't reacting and vice versa. So in a non-allergic person, some of your cells are still saying this isn't okay,

but it's a fraction of the cells. So you're not experiencing the symptom. Yeah. That reminds me of a conversation I had about cancer and how we all as adults have cancer cells within us, but the immune system's on top of it. And the balance is such that we don't have the diagnosis of cancer. It's when the balance starts to change. And it's maybe not quite the same thing, but it's quite a similar, I think, theme there that things are going on in the body always. And just because we're not getting symptoms doesn't mean there's no problem. Right. In fact, there's an interesting overlap there. So people that have allergies tend to have lower rates of certain types of cancer, specifically certain forms of skin cancer and some gliomas. And one of the theories,

we don't know why, I mean, it could just be correlation and not causation, but one of the theories is perhaps someone who's allergic actually has a really strong immune system. I think there's this idea that people with allergies are weak or somehow maladaptive. And actually they have incredibly strong immune systems that are just responding to the wrong stimulus. And so their bodies might be able to spot cancerous cells more quickly and more aggressively because they're already primed to respond, if that makes sense. Yeah. That's really interesting, isn't it? Allergy sufferers may have lower rates of certain cancers. And it makes me think, I mean,

we're going to talk now about the gut microbiome. I really want to get your perspective on that in relation to allergies. And you referenced a lot of Dr. Catherine Nagler in the book around this. But this idea that the gut microbiome is really important. And regular listeners to my show will be aware of the microbiome. We've covered it many times on the show, specifically in relation to what foods and what lifestyle changes can help support a stronger and more resilient microbiome. But when I think of allergies and I think about this is an immune system that, I don't know if misfiring is the right word, is something's just out of balance with the immune system. I'm also drawn to autoimmune disease. Right. Where in autoimmune disease, the immune system is reacting against itself or the body's own cells.

And in allergy, the immune system is reacting to the outside world. An analogy, the immune system is reacting to the outside world. And then I've read so many interesting studies on, I think it's in Indian villages, where people who have the presence of certain parasites like blastocystis hominis have got lower rates of autoimmune disease. So as I've been reading your book over the last few days, I've really been thinking about this potential conundrum whereby, is the cost of having a, in inverted commas, clean world where we don't get infections as much, is the cost of that an increase in allergies and an increase in autoimmune disease? Whereas in certain cultures where they have regular parasitic infections and maybe they're

getting symptoms of that, there does appear to be evidence suggesting that they have certainly lower rates of autoimmunity. I can't say I'm aware of the research for lower rates of allergies, but I suspect it may well be. So is it that we need almost that low-grade infection in our guts to tune up our microbiome and our immune system, which then is protective? Do you know what I mean? I really think about this. Is it even possible? protective. Do you know what I mean? I really think about this. Is it even possible? I mean, we're not, I want to be really careful here because I'm sure you're aware that there's an underground movement where people are ingesting, they're trading and ingesting worms, intestinal worms to try to self-treat things like eczema, but often they cause themselves trouble. So they'll ingest pinworms to try to tamp down the immune system. And it does seem to work some of the time. So

one of the theories is that, so our immune system was built for a different world. So we were coming into contact with a lot more venomous things. We had a lot more parasites. And so the allergic part of the, so the different pathways that the immune system can take that the allergic part and the autoimmune part is basically was built for those things so that it would protect you. And in fact, they've done studies in mice where if you knock out those IgE antibodies that I was talking about, and then you give the mice doses of a snake venom that was commonly found in Israel, that those mice die at a much higher rate. So their anaphylaxis just, you know, they go straight into toxicity and expire. But if they have the IgE, it actually does have a mildly protective effect. So they

survive more often. So there's obviously something about this system that was built to protect us against certain things that just, I mean, I don't know about you, but I haven't been bitten by an asp anytime recently. I'm not regularly getting snake bites. And so one of the theories is that that part of our immune system is rather like a bored toddler. So I don't know. I mean, I know you have children. So if you leave them with nothing to do, they'll find something to do. And it's not necessarily what you want them to be

doing. And so those components of our immune system is like that. They're there, they're ready to work, but they're not being given the things that they normally would have been given. And so they're kind of looking about for things to do. Yeah. It's like the subtitle of your book, How Our Immune System Reacts to a Changing World. You know, that's kind of it in a nutshell, isn't it? Yeah. In the book you outline, you go through the sort of various theories that have come over time as to why

we are so allergic. You mentioned the hygiene hypothesis, the barrier regulation hypothesis, and I think you've coined something called the we are doing it to ourselves hypothesis, which I really like. I think that could catch on. Perhaps you could sort of walk us through some of these theories and what do we know as of 2023? I'll start with the hygiene hypothesis, because if anyone has heard anything, it's probably this one, that we're too clean. So the original theory was based on research, a meta study. So a researcher's looking at all the various studies, looking at specifically asthma and respiratory allergy rates in, I think, Britain. And what he discovered was that younger children, so if you were in a multi-sibling household and you had elder siblings,

you seem to be protected from allergic disease. So the oldest one might have allergies, but the youngest had much lower risk of developing allergic disease. And so this researcher posited that, why would that be? And he thought, well, kids are germy. Like, you know, they go off to school, they bring things back, you're constantly getting sick. So that what will happen is that the younger children will get exposed to all of those things at a young age. And then somehow that was having a protective effect. So that got turned into this idea that was supported by a couple of studies that were done in Germany and Switzerland that suggested that living closer to microbes, specifically those in barns. So it's called the farmhouse effect and it's related to the hygiene effect. And basically what they found is if you

lived in a farming community and as a child, you were being carried in and out of a barn with ducks and cows and pigs and what have you. And the key thing was the livestock. They don't know why, but if the farm had livestock and the child was brought in to the barn on a regular basis before the age of three, the rates of allergic disease were incredibly low when those children got older. And they really don't know what's so magical about farm dust. They don't know, maybe it was the animal dander mixed with bacteria, mixed with allergens. So, you know, of course you have hay and so you would have natural allergens also in that barn. And so they think maybe there's something about that mixture that farm dust from a farm that has livestock was protective.

And so that lent itself to the hygiene hypothesis. But we now know, like if you look at farming communities now, they have the exact same rates of disease. And we kind of have discredited that as the smoking gun. So it can't just be that we're too clean. And the other evidence is that we got clean a lot sooner than we got allergies. So if you think about the history of hygiene and all the sanitation efforts, we started to clean up our act, so to speak, a lot quicker than we got the bump of allergic disease, which really started blossoming after World War II. But could that also be, if we think about the innate and the adaptive system and how

the adaptive system takes a bit more time, and if we get time today, I want to talk about how repeated exposures can often get worse. Or you have this scenario now where, if we get time today, I want to talk about how repeated exposures can often get worse. Or you have this scenario now where, if that's a friend's friend yesterday, when they knew I was speaking to you said, hey, listen, can you ask stories about my, I think it's my mum who never has had hay fever before, but after she cut the grass a few weeks ago, felt really bad. And when she stopped, like, so this, this idea that, um, repeated exposure can start to, you know, people can suddenly get symptoms in their sixties when they've never had an allergy before, which I think is pretty common now that people are getting it later on in life. So I wonder, cause, cause we know that, you know, that research has shown that kids who

grew up in these farms had a lower rate. It doesn't mean you're never going to get it, but just a lower rate. So as you say, it's maybe not the smoking gun, but it could be part of the story, right? Right. And the reason we think that is this dovetails into the microbiome or the barrier hypothesis nicely. So we've updated the hygiene hypothesis to something we call the old friends theory, which is that sure, obviously it's great that we don't have TB anymore or like cholera is not a serious problem for a lot of us, but that there's really good bacteria that are helpful to us and bad bacteria like cholera that we obviously don't want. But the problem is, is that antibiotics, sanitizers,

they don't discriminate. So they're indiscriminately killing everything and that they're killing our friends. And so if you look at the gut microbiome, so Kathy Nagler at the University of Chicago has looked at babies who have allergic disease. And when you look at the genetic makeup of their guts, they're strikingly different from babies that do not have allergic disease. So there's a different

composition of the types and numbers of bacteria in those guts. And so her hypothesis is that the gut microbiome has a key role in regulating the immune system. So that our immune system trains itself partially on the trillions of organisms inside of us. And if those get off balance or if there are types that perhaps weren't there in the past and they're absent, some types that we would have evolutionarily co-evolved with,

that those changes are causing our immune system to have a tougher time regulating and a tougher time training in the early years. So from age zero to three is when your immune system really changes a lot. Yeah. It reminds me of, I don't know if the book came out 10 years ago now, Missing Microbes by, I think it's Martin Blaser from Recollection, where he put forward the idea that, you know, him and many others, I think, put forward this idea that is the fact that our microbiomes are so deplete

relative to what they were before or what they are in some hunter-gatherer tribes, even to this day. The fact that we maybe have lost up to 50% of our diversity, some studies are showing, I think some maybe even more than that, is it these missing microbes that is ultimately underpinning our dramatically increasing rates of autoimmune disease, allergy, other chronic diseases. And it's really interesting and I guess that fits with this old friends hypothesis. And it's really interesting. And I guess that fits with this old friends hypothesis. And you mentioned Catherine Nagler in the book quite a lot about

food allergies, but you also mentioned when it comes to microbiomes, I think it's, you know, you mentioned the vaginal microbiome, but there's microbiomes everywhere. There's a microbiome on your skin. And you quoted a study, I think, where they put a strip, an adhesive strip on someone's, they had a control group. I mean, do you know, maybe you could say the study was really interesting. Yeah, it was actually mice. So what she did was she stripped the microbiome using adhesive tape of mice and then applied an allergen. And what she found is if you strip that microbiota, then the mice had a much, I mean, basically the skin becomes leaky or more porous. The allergen gets into the skin and into the bloodstream immunologically intact, which means that it's not being broken down.

So usually when things come into us, it's through our digestive tract and we break things down. And then of course they're absorbed into the bloodstream, but not in their intact form. And it's really when our bodies get it intact that it goes, hey, wait. What is this? What is this? And so one of the theories, especially about food allergy is that, and of course eczema, is that when you strip that microbiome or change it on the skin, that you are priming your immune system to be like, hey, what's going on? Like this shouldn't be here. Like things are getting in in forms that they wouldn't normally get in. So it's possible they think that,

say you make a peanut butter sandwich and then you pick up your baby and you have traces of peanut on your hands. And if your baby is unfortunately, you know, carrying a genetic predisposition and has more porous skin, that that peanut butter is seeping in. And then they, when they eat peanut butter, their bodies will have been pre-sensitized via the skin. So it's not even there. It wouldn't be

their first time coming across peanut is not via the normal route. It's through the skin. Yeah. You mentioned the early years and those first three years of life and how the exposures a child has at that point, a baby has at that point, an infant, toddler, right, at that point, a baby has at that point, an infant, toddler, right, are really crucial at determining what's the signature of that microbiome going to be. And we know, don't we, that actually what happens then can hugely influence what happens later on in life. Now, again, I don't want anyone to feel guilty about that, right? Because as I say it, I can just hear and feel the parental guilt. And just to be clear, right, if I knew everything I knew now when my kids were born, I would do some things very, very differently for sure, right? I think I've done a lot right, but we're all doing the best that we can i want to make that super super clear at the top here but the fact that those early years are important i think there's there's

a really there's a really important wider point here i think we're learning that i spoke to dr gabol mate a few weeks ago right um on the show for the fourth time actually. And again, Gabor was talking about the early years, how we're parented, how we form attachments are really important for the state of our nervous system and our risk of all kinds of problems later on in life, right? So from a mental health perspective, early year attachments are important. From an allergy perspective, right, and risk of autoimmune disease in the future, the inputs that go into a child and a baby from food and what's on their skin is also very, very important. And then you've got to ask the question, as societies, what are we doing to support those critical early years? Because if all healthcare

systems are struggling, if allergy rates are going up, yet we can say we don't know everything yet, but we do know that the early years are important. Surely it makes sense to go, as societies, how can we support parents, communities, families in those early years. And you come from a country where, I would say, certainly from the UK, and I'm not saying we're perfect at all, especially when it comes to, if you compare us to, let's say, certain Scandinavian countries. But in the US, maternity leave, it's crazy. It definitely feeds a capitalist system. It serves that very, very well. But does it serve the health of the children and therefore healthcare systems? No. No, not at all. And you can see this play out in socioeconomic groups. And of course, in the US,

that tracks often with racial groups. So you will find higher rates of asthma in underserved communities, higher rates of food allergy, except that it's not as diagnosed. And there are various reasons for that. But, you know, they're growing up to go back to the air pollution connection. You know, like that's something you can't control. So they've shown that, you know, if so, they did this research at Cincinnati Children's Hospital where they took children that were born just random assigning groups where you were either really close to a roadway where you had a lot of diesel engines and trucks going by, or you lived further away. And what they found was that the closer you are to exhaust, the higher your chances of developing asthma. And if the child moved, if it was after the first three years of life, that risk continued. So it's obviously in the early years that are critical and it matters where someone lives and the air that they are breathing and the food quality that they are

having. So like, you know, in the U.S. we do have food stamps or, you know, assistant programs, but they're patchy and it's hard to get approved in some states. And so what's the quality of the food that the parents are giving these young children? And again, it's not their fault. Yeah. It's not the kid's fault. It's not the family's fault. Right. And then there's also researches that you share that if up to the age of three, if you grow up with a pet, like a dog, you also have lower rates of allergy. And they think that's, again, bacteria. So the dog is out in the world snuffling around and then coming in and licking your kid's cheek. And that that low level bacterial introduction

is actually somehow protected. But again, it's this whole wider point where we have been trained to go, all bugs are bad. We need to kill bugs. And listen, of course, antibiotics have been life-saving. I completely get that. But like with most things in life, there's upsides and there's downsides. And there has been a huge downside, not only with antibiotics for the over-prescription of antibiotics in humans, but also all the antibiotics being used in cattle. I mean, how does that play in here? Before we get back to this week's episode, I just wanted to let you know that I am doing my very first national UK theatre tour. I am planning a really special evening where I share how you can break free

from the habits that are holding you back and make meaningful changes in your life that truly last. It is called the Thrive Tour. Be the architect of your health and happiness. So many people tell me that health feels really complicated, but it really doesn't need to be. In my live event, I'm going to simplify health, and together, we're going to learn the skill of happiness, the secrets to optimal health, how to break free from the habits that are holding you back in your life, and I'm going to teach you how to make changes that actually last. Sound good? All you have to do is go to drchatterjee.com forward slash tour and I can't wait to see you there.

This episode is also brought to you by the Three Question Journal, the journal that I designed and created in partnership with Intelligent Change. Now, journaling is something that I've been recommending to my patients for years. It can help improve sleep, lead to better decision-making, and reduce symptoms of anxiety and depression. It's also been shown to decrease emotional stress, make it easier to turn new behaviours into long-term habits, and improve our relationships.

There are, of course, many different ways to journal. And as with most things, it's important that you find the method that works best for you. One method that you may want to consider is the one that I outline in the three-question journal. In it, you will find a really simple and structured way of answering the three most impactful questions I believe that we can all ask ourselves every morning and every evening. Answering these questions will take you less than five minutes, but the practice of answering them regularly will be transformative. Since the journal was published in January, I have received hundreds of messages from people telling me how much it has helped them and how much more in control of their lives they now feel. Now, if you already have a journal or

you don't actually want to buy a journal, that is completely fine. I go through in detail all of the questions within the three question journal completely free on episode 413 of this podcast. But if you are keen to check it out, all you have to do is go to drchatterjee.com forward slash journal or click on the link in your podcast app. It plays in a great deal. I mean, you know, most of the researchers I spoke to just lament that because it is killing off commensal bacteria that drive our immune systems. So you're, and they have found that, unfortunately, again, like I don't want, I also am worried about people feeling guilty, but if children have a lot of antibiotics prior to the age of two, so say you had four

bad air infections, so you got four massive doses of antibiotics when you were younger, it does lead to a higher instance of allergic disease when they're older. And the theory is that it is dramatically changing the microbiome because, again, an antibiotic is like a sledgehammer. It's just knocking out every bacteria. It's not distinguishing. Yeah, and we know from the research that some microbiomes bounce back quickly. Right. Others, two years later, they're still not the same, right?

And again, so there's an individual change here one thing i noticed um and this you know my son's 13 now so when he was six months old and he was in a hospital in france i really noticed then back then at least a big difference with how French doctors compared to the British doctors I was exposed to were dealing with things. And I really sensed, and I spoke to one of my buddies out there who's a doctor in France, that in France, at least then, and this is not a scientific paper, this is just my perception of what I saw. There was a real reluctance to give antibiotics without real hardcore proof that it was a bacterial infection. Whereas my perception at that time was in the UK, it was a much more freer prescription. Let's put it like that. Okay. And this was back in 2010. So culturally, I think

there's a culturally different doctors and healthcare professionals will practice differently and they'll have more willingness or less willingness. And a question I always want patients to ask their doctors, which I don't think doctors encourage enough and I don't think patients ask enough. And again, you know, I'm not having a go at enough and I don't think patients ask enough. And again, I'm not having a go at patients. I want to help them say, well, what happens if I do nothing here? I think it's such an important question before you take anything. What happens if I do nothing? Because often a doctor will give, and I get it. I've been in this position many times. You've got a busy clinic. You've got four people waiting outside. There's a young child who's got evidence

of an ear infection, right? They've got a fever, they've got a worried parent, and often societal pressures that parent wants to get back to work as well. And so you've got all these factors playing into that interaction. The easiest thing in the world is to do a prescription for an antibiotic. Yeah. And they expect it too, don't they? And they expect it. Yeah. But again, I don't want this to be about blame. I think people expect it because that's been the conditioning that bugs are bad. But a lot of these infections, and again, some are serious, they need to be treated. If they don't, they can have long-term consequences for sure. But a lot of the time we're treating things where we could hold off a bit longer and go, if this isn't better by this time, or if your fever goes

above this, or if this symptom's happening, then think about it. But until then, just try and manage it if you can. Because then if you think about adaptive and immunity, you're also, your immune system's being trained and learning, isn't it? Yeah, exactly. And I mean, they've started to try to do cultures also. So before prescriptions, they'll culture and see what bacteria is causing it and if they're susceptible to, because that's the other problem is, of course, I'm sure you've discussed it on the show before, microbial resistance. So like antibiotic resistance is a big problem and a growing problem. And so that's also part of this story is that not only have we relied too much on antibiotics probably throughout the years,

but so we've created a double-pronged problem. Like we've got resistance, but then we've also got the situation where it's altering our gut microbiome considerably. And that barrier hypothesis. So the barrier hypothesis simply says that under normal circumstances, our barriers, so our skin, our intestinal tract, our nasal cavity, they are replete. They have their own ecosystems. They're finely balanced and all things being the same that our immune cells have a relationship with the things on them that actually is beneficial and provides a barrier. And if something happens to those barriers to make them more porous. So in the case of food allergy, you get food proteins absorbed again in an intact form that your body is not used to. So, and one of like, for instance, something as simple as taking an anti-acid. So how many people

are on something for indigestion or taking a Tums or something like that. And they've shown that if you're taking a prescription antacid, it's changing your gut microbiome and it actually is, you're decreasing the acid, which means your food isn't breaking up, which means it's getting absorbed in a more intact form that your immune system is freaking out about.

So you're solving one problem and creating another. And so what do you do? Do you want the heartburn or do you want... Yeah, or there's a wider conversation here, which is, or do we need to think about these symptoms in a less reductive manner? Because I can tell you that the vast majority of cases with heartburn, if you know what to look for and if you have enough time to do this you can find what's causing it right but because of the way the systems are in the medical system and the way we practice it's easier to give an antacid or a ppi a proton pump inhibitor which may initially help the symptoms. And then the problem is,

and this I think all plays into allergies and autoimmune disease, is that, as you say, on one hand, you fix something or you think you're fixing something. At least the patient has gone away. They're feeling better that they've got something and symptoms are at least a little bit better. But all the initial studies on PPIs, I think were four weeks maximum. You go into any GP practice in the country and see how many repeat prescriptions continuously for PPIs there are. It is staggeringly scary.

I've had a friend on them for about five years. And the problem also is, is that then people think when they stop it and they get symptoms, they think, oh no, I need the, I still need the PPI. But the problem is you get rebound symptoms. So it's like an alcohol. It's not the same thing, but let me just draw the analogy. If you're an alcoholic and you stop drinking, suddenly you're going to get symptoms. You're going to get shakes. Right. It doesn't mean that you needed the

alcohol. It's a withdrawal symptom. And you see this with PPI. So people then stay on them longer. And it's not just allergies and absorption. We know long-term PPI use is associated with vitamin B12 deficiency because you need acid to absorb B12. So I think this all plays into the topic we're talking about, that the health of the gut microbiome is really, really important. So as we learn more, we need to do better as doctors, as society. I wonder if we just tackle this in two different ways, because I want to make sure we at least come up with, you know, we can't go through everything in the book, frankly.

It is so thorough. Can I just actually, can I just talk about stress? Yeah. Well, I want to, yeah. Because we're talking about proton pump inhibitors, and can we just talk about the relationship between acidity in the stomach and stress? And, you know, like stress has certain effects on our bodies. And one of the experts I talked to, Dr. Peter Leo, said you can absolutely, he's an eczema specialist, and he said you can absolutely track when someone is experiencing greater levels of stress in their daily life, their skin changes. I mean, it's a one-to-one. You can see the microbiome and the skin porosity change.

And obviously it has an effect on the gut microbiome as well. And so we're living quite stressful lives, right? I mean, most of us are worried about making ends meet or childcare or taking care of elderly patients. Like what? Elderly patients. Elderly parents. And elderly patients.

And elderly patients, which there are more and more of every day. So those stressors affect your immune system. So it's not just the outside world as in pollen or dust mites or food proteins. It's also the outside world in terms of the social pressures and economic stressors that are changing our biology as well, stress, any sleep, nutrition, I mean, anything can change it. And so you'll often have people say, well, last year or last month, my symptoms weren't as bad.

Well, maybe your stress level changed or, you know, women experiencing pregnancy or menopause will have sudden new allergies that they didn't have before because there's a huge effect of hormones on these systems. So it's just, it's such an intricate web. And I think to go back to that point of, this is really a social problem. That's obviously a social problem. Like the way you respond to stress,

sure, it's an individual biological concern, but how can we escape stress? Like, where are we going to go? Are we going to live on a mountaintop cut off from everything? Yeah. And this is where it becomes a vicious cycle, doesn't it? Because the allergy sufferer who's not taken seriously feels frustrated that the world around them doesn't get how bad it is for them. They're tired, they're irritable. They don't sleep as well because they're itchy, which makes them more tired, more irritable, less empathetic because we know a lack of sleep decreases your empathy. And then we know that a lack of sleep is a stressor on the body, right? It's a stressor on the immune system. So it really is quite a toxic, vicious cycle when someone has got

unmanaged allergies and inabilities get on top of it. It can affect their relationships, it can affect their health, it can affect their happiness. In fact, you outline some of the research in the book whereby I think the relationship between increase in allergies and an increase in mental health problems, but also the other way around. So an increase in mental health problems like anxiety and depression can also increase allergies, which is really, really interesting. Yeah. And there seems to be, if you do studies in people who have even mild allergies, it tends to track with greater levels of anxiety and depression. But again, it's, yeah, it's constantly losing sleep. It's constantly not feeling your best. Your immune system is constantly on. And that eventually will take an emotional toll, a mental toll. And so it's a bit the chicken and the egg,

like what's causing what? It's hard to tear that apart and look at it. The problem often with stress is, and I think we as a profession have to take a bit of responsibility for this. Sometimes the way we've communicated it to our patients makes them think that we're not taking them seriously, makes them think that, oh, they're just trying to fob me off and put it down to stress. But stress is real. Stress has real biological and physical effects on the body, right? And you show in the section of stress in the book, stress impacts allergies via the histamine released from mast cells. Right. So your mast cells are really sensitive and they will respond to higher stress hormones or chemicals in your system

and release histamine, which is a stress response. I mean, like I said, mast cells only release histamine when they feel stressed. So when they are feeling, either when they get damaged or when they are feeling under threat, they will release histamine. So your body thinks it's, histamine is like a red flag for your body. So it is not a nice experience. It doesn't turn on good things. And there's some now studies, I think, showing that mindfulness and meditation can help reduce severity of eczema symptoms and how many flares. And once you understand the biology of the immune system and stress's impact on it, it's like, yeah, of course that makes sense. It's not just this fob off. It's actually, no,

this is real. It may not be the whole picture, but it may be part of the picture. It's definitely part of the picture. And in fact, in India, a researcher I talked to there who specializes in asthma often prescribes yoga for her patients. And the reason she does so is it calms the immune system and also it trains them how to breathe. And so when they go into an asthma attack, they kind of naturally understand how to control their breath. And so she finds that the de-stressing helps, but also the breathing techniques help. So she will assign that in conjunction with giving them an inhaler. So she kind of tries to tackle the problem holistically rather than just treating the biological symptoms. And I think the only way we're really going to get on top of people's allergies or at least help them

be manageable and improve their quality of life is by taking this rounded holistic approach. So if we think about things that we can do for just a moment, so you've sort of walked us through the hygiene hypothesis, the barrier regulation hypothesis, I think that Catherine Nagler talks about, that we are doing it to ourselves hypothesis that we are literally covering throughout this entire conversation, this idea that fundamentally though, what's the interface between us and our outside world? It's through our microbiome largely, isn't it? That's a huge part of it at least. It's our cells, our immune cells plus the microbiome. Yeah. So, and we don't really understand the conversations that they're having,

if that makes sense. We don't really understand their interconnection and what components are crucial to that conversation going well. And then you have the external things coming into contact with, I mean, it's interesting because I consider like one of the changes for me writing this book is I consider those microbes me. If that makes sense. Like they're me. Without them, I would literally be unable to survive. And so I've just changed my thinking. be unable to survive. And so I've just changed my thinking. So the external thing, so I'm touching this table, the microbes on my hands are still me. So they're both my cells and them are coming

into contact with the cells of this table, whatever is on there. And it's trying to understand that connection about like how they are working together to switch things on and off in relationship to the things we are encountering. Yeah. It's just fascinating this idea that we have more microbial cells in our body than human cells. I think that's been one of the big aha kind of realizations over the last five, 10 years of microbiome research. Yeah. I heard someone that studies the microbiome just the other day say that it's like there was an organ we didn't know existed until 10 years ago. Yeah. A whole organ. Yeah. And it weighs, I think maybe as much as the brain, I think it's pretty profound. And I think it's also

really interesting if we think about our relationship with our surroundings, most mast cells that we've been talking about throughout this conversation, the mast cells, of course, are what release histamine that give us a lot of the symptoms we associate with allergy, itching, redness, stuffiness, whatever it might be. The highest concentration are at the three areas where we interact with the outside world, right? In our guts, because that interacts with food from the outside world. In our respiratory tract, lungs, nasal cavity, where that interacts with things that we inhale from the outside world. And then also under our skin,

because that's obviously interacting with the outside world the entire time. So then if we say that the barriers are important, what are the things that we can do then to support those barriers? I think it's trying to re-engineer our brains to stop associating automatically microbes with negative, bad things. So germ theory did a lot for us, but unfortunately, it made all germs into enemies. And I think I try to make decisions for everyone now. So I think of myself as a confederation, if you like. And so I think about, all right, do I really need that hand sanitizer? Or even simple things like, you know, nobody ever thinks about this, but if you use a dishwasher, like I get it, it's easier. It's, you know, water efficient, but those,

the detergents we're using in them and the heat destroy all the leftover bacteria that you have on dishes from food and just from you eating that are actually beneficial. It's like if you wash, hand wash a dish, enough bacteria stays on there and you get most of it off, but like a little bit stays on. And it turns out a little bit is good. So I try to make those decisions. So I'll hand wash my dishes versus throwing them in the dishwasher. Or so I'm just constantly thinking not just about what's easiest for me and what do I want, but what do the things but what do the things in me and on me want? And it's not to be constantly stripped away.

Like if you think, especially about our skin, like the amount of stripping that we do, like in the shower, scrubbing, scrubbing, scrubbing with the harsh soaps. And you're destroying whole communities. I sound like I'm talking about the who's from Whoville, but it is a little bit like that, that whole worlds exist on us that we are impacting without even thinking about it. So I just think we all need to, A, do more research on, we really don't understand this world at all. Like we do not understand. I mean, we're not even sure exactly what is in our guts. I mean, so they'll do like genetic typing of things in our guts and we'll see gene sequences that are not recognizable. Like, and so we don't even know what's there. But we do know what's, we know a lot about what's damaging them, don't we?

Yes. Right. So I think that's the empowering piece is, there's a lot we can't change about society for sure. But, you know, I don't know how many people are going to use their dishwasher less on the back of what we're saying about how stressful life is and how busy people are, right? Because you might be increasing your stress load somewhat.

But just to start, I think what's empowering is just to start thinking I think what's empowering is just to start thinking about these things and going, okay, well, what products am I buying? What's in them? Is it full of, you can get more natural, kind of less toxic products to use. Yes, but again, they're expensive. Exactly. So for people who can afford it, right, and have the resource to do that, that is one thing you can do immediately. Eat the skin on fruits and eat the potato skin.

Like try to think, okay, am I giving the microbes in my gut what they want to eat, which is maybe not what I want to eat. So, you know, I'm forcing myself to have more broccoli, you know, like, but really and truthfully, that is important to think about feeding them because they're feeding you. What about the pesticides that are used on fruits and vegetables these days? I mean, that is another whole kit and caboodle because now you're introducing more chemicals. I just love that phrase. That's a whole... Kit and caboodle because now you're introducing more chemicals. I just love that phrase. That's a whole- Kit and caboodle.

Kit and caboodle. I love that. I don't know that one. But I can infer the meaning from the way you said it. Yeah. It's just a whole mess that you're introducing all these, again, some of those chemicals your body would never have seen. And yet, you know, the way we produce food is very different. Like the way we grow food is different. And that's all having, I'm sure, ancillary run-on effects. For sure, we know we're getting too much sugar, too much fat. I'm sure you've talked about that a thousand times on this podcast. And that's feeding the bad bacteria, so to speak, or it's imbalancing

anyway. Like it's, it's, it's basically creating a situation in your gut where you have some microbes that are flourishing with all the extra fat and sugar, but you're starving the ones that need the skin on the apple that need more kale. Like, and so I try to make, we can all do better in that way and think about less processed foods, like trying to get food delivery to people in more whole forms. Have you found from talking to these allergy experts around the world that this stuff, when we do, can make a difference to people's allergy symptoms? Especially in the early, like again, in that early crucial period when you're dealing with children, like trying to give their immune systems the best help that you can. So I definitely get that, you know, for people who are, let's say there's a

pregnant lady listening to this right now, this is great information for her to know going into the first two or three years. Okay. These are really important. What can I do here? Okay. But there's many of us who through no force of our own didn't have that, or maybe had a load of antibiotics for ear infections when we were little or whatever it might be, or had a cesarean for very good reasons. So maybe we didn't get the best start. I'll tell you my own experience because I've seen a lot of allergy patients in one of my clinics over the last few years. And I have found that when you take a multifactorial approach, you're not looking for one smoking gun.

When you try and reduce the toxic load on these barriers, right? So, you know, helping people to clean up their diets compared to what it is, you know, helping people to clean up their diets compared to what it is, you know, reducing their exposure to various toxic inputs, you know, helping them have less stress in their life, right? Which can be hard, but there are also things that can be done. Yeah, of course. And maybe supporting their gut microbiome potentially with dietary changes or whatever, you can see a marked decrease. Not in everyone, but with many, you can.

Yes. But it's very rarely, in my experience, just one thing. Right, exactly. Because, I mean, all of those theories... So I would ask people... So I interviewed, you know, just dozens and dozens of the top experts on these issues and top researchers. And I would ask them, if I forced you to choose what is causing allergies, what would you say? Because I just wanted to get a lay of the land. And all of them refused to answer that question and said the following.

It's everything. It's everything we're doing. it's everything. It's everything we're doing. They wouldn't come down on a side because it is, our bodies are getting bombarded from all angles. So our immune systems are just getting overwhelmed at every point of entry. And so it is all of the things we're doing. It is the dishwashers. It is the detergents. It is the, you know, using non-cloth diapers. It's, you know, increasing levels of CO2 in the air that is producing multitudes of pollen, pumping out more particulate matters. So that's irritating our lungs. It's all of it. And so if you try to tackle this from just, so people are, I often feel bad because when you read this book, one of the things I thought about was

like, well, God, it's kind of, it's not depressing, but there's no easy solution. Like if you pick up my book and you think at the end, it's going to be like, here's how you're going to get rid of your allergies. You're going to be so disappointed because it requires a big societal shift in how we're doing things. Yeah. Look, I don't think they're going to be disappointed because if you're looking for a quick fix, what's the thing I haven't heard about yet that if I start taking, it's going to get rid of these, then I think you're going to be disappointed. If you're looking to understand it better and figure out, oh, that could apply to me. Can I reduce that exposure? That's probably not relevant for me,

but that bit is. I think it's quite empowering to help people build up a picture around certain things that they can potentially change. I mean, one thing we've not mentioned yet really is diesel and particulate matter. And even this idea that particulate matter, so diesel fumes can make allergies worse. So it's not necessarily that we're allergic to the diesel fume. No, not at all. But it's doing something to the allergens. Could you maybe just touch on that? Well, it's irritating to our lungs. Like, you know, those particles are not, I mean, they're foreign and our immune systems are not excited about them being there.

Diesel more than petrol. Yeah. So diesel exhaust. So like what we're talking about here is ultra fine particulate matter. So most places only measure it's 2.5 microns to 10 microns. And just to give people a sense of what we're talking about, a red blood cell is five microns in diameter. So we're talking about particles that can be as small as one micron. And so their ability to get deeply into our lungs. So when you think about that small of a particle and you're inhaling, it's able to just go much deeper into the lung cavity. And what they've found is that pollen will attach themselves to these particulate matters.

So they get kind of glommed up. And so when you're breathing in, the pollen is actually going a little bit deeper and causing more of a problem. And the same thing happened, they think. One of the theories is that if you look at COVID rates during the pandemic, they could fluctuate, but about 40% of the fluctuations could be correlated to the amount

of pollen in the air because also the virus is able to attach to particulates and pollen. And so you're just, you're inhaling these particles and depositing. It's almost like the pollen is getting an Uber lift or a cab lift deeper into your lungs. Do we know in the early COVID lockdowns, when in many countries or many urban environments, travel stopped massively or was greatly reduced. For some people, clearly many workers, it wasn't reduced for them. But we know that levels of pollution came down significantly. Now, on one hand, levels of pollution are coming down, which is a good thing. On the other hand, stress and fear is going up.

Correct. Sprays and hand cleaning and toxic substances is going up, right? So do we know when we look back now, were people complaining less of allergic symptoms at that time? Well, the interesting thing is, so all I have is anecdotal data. So nobody was really, I mean, we were all so stressed out and just trying to cope with the pandemic that not many people were like, aha, let me do a study on allergies during this event. And who's going to the doctor to report allergies at that time as well, right? Exactly. But I have heard from researchers and clinicians who,

especially with asthma patients, they had less episodes. So they were using their inhaler less frequently and they in general felt better throughout that period. And because people were masking, remember for that brief time, people were masking also outside. And so the masks were, the theory is that perhaps also they were obviously filtering out pollen. So people were just reporting a lot less respiratory symptoms throughout that period. But I have to do a little comma, but if you were allergic to dust mites or an internal allergen, it went up. When you say internal, do you mean inside the house? Inside the house.

Because that's another thing. When we think about pollution, we're thinking about outside, bus fumes, diesel fumes, car fumes, airplanes, right? But actually, sometimes indoor air can be worse than outdoor air. Absolutely, right. And so that's what they found, that if you suffered from like a pollen allergy or a pollen trigger for your asthma, and you were just getting cleaner air that your asthma events went down, probably because a combination of mask use and less particulate matter. But if you had an allergy to dust mites or dust or anything that could be found indoors circulating,

then you had no protective effect and in fact might have gotten a bit worse because you're spending more time inside with your dust mites. What's really interesting for me is when you were supporting your, we are doing it to ourselves hypothesis you you brought up the case that pets that we you brought up the animals that we've domesticated so pets dogs cats i think you said some horses horses are also now displaying an increase in allergies whereas the animals who are still in the wild maybe are not so, supporting this idea that there's something about our human environments that is causing this, which I found really, really interesting.

I mean, it's really fascinating. So I went to speak to some veterinarians at Cornell Veterinary School, which is one of the best veterinary schools probably in the world. And they said that they've absolutely seen an explosion of allergies in pets and it's underdiagnosed and under-surveyed. So they really don't have great numbers for me. Like I said, what's the picture look like? And they said, we can't really tell you, but we can tell you just based on our own practice and what we're hearing around the country. And the symptoms are very similar to us. So in dogs, it's itch. So they're scratching a lot, like obsessively and

having open sores. In cats, it's asthma, actually a lot. So they're sneezing and coughing. Also a little bit of itch in birds, our pet birds, it's itch and coughing. And in horses, it's itch and coughing. There is some evidence that pigs and cows are also developing allergies. And there's no evidence that a deer or a fox or anything out there living its own life away from us have them. have them. So obviously the things that are happening to our immune system are also happening to the immune systems of the things that live our exact same lifestyles. One of the most compelling points for me is that often if they can find the trigger, which sometimes they can't, a lot of the times it's their food. So if you think about it, we have changed our pets' diets also. Right? I mean, we- We don't consent to just screw it up for ourselves. Right. Yeah. So we're opening a can of manufactured food and we're feeding them.

And so we could be disrupting their microbiomes because all animals have, I mean, similar immune systems. And so obviously whatever is happening to them is a reflection of what's happening to us. And that to me is some of the biggest evidence that we are definitely doing this. And there's stuff, you know, we haven't gone deep into these chemicals, but it's in carpets and paint, in our sofas. There's so much now, like the stuff that's put in to make things fire repellent. On one hand, great, right? There's a benefit. On the other hand, potential negative effects on people who are susceptible. And it really is quite baffling and bamboozling when you start trying to get into this. Because of course, as we mentioned, there is a cost element.

But I think just coming towards the end of this conversation, I have usually seven or eight different factors that I'm looking at with patients with chronic health issues that I think cause them and can also potentially be manipulated and changed, right? So if I think about them through the lens of what you've written about in your book and what we're talking about with respect to allergies, okay, let's start off with what I call these four pillars of health, okay? Food, movement, sleep, and stress. And let's look at them through the lens of allergies and the fact that we're trying to support our microbiomes and our immune system and our barriers wherever we can. Okay, so what can we do with foods? Well, it's advice people have heard before, but it's

worth reiterating, right? As much as you can, whole foods foods fresh foods if you can you know diversity if you tolerate that try and reduce your intake of modern food like products ultra processed foods basically try and eat in a way that supports your gut microbiome would you agree with that yes absolutely and it's closer to the way we would have eaten in the past yeah so that So these old sort of maxims like your great grandparents would have eaten, that sort of thing. Okay. So that's something practical we can do around foods. Okay. Then let's go to exercise. Okay. We've not really discussed physical activity in relation to this. I guess if I think about air pollution and I think about, okay, try and be careful when you're going for your walks. If

you've got a park or a forest to get to, that's probably going to be better, but still move your body as much as you can. And I know actually in India, I believe that there's certain advice in certain countries to walk, go for your walk at times when air pollution is lower, which I find really interesting. Yes, that makes complete sense. And try to stay away from busy roadways. Yeah. So again, that's something practical that's going to lower the loads on the immune system. Okay, stress. We've mentioned already in this conversation how negative stress can be for our immune system and for allergies. So, you know, there's all kinds of things people can do. I've done many podcasts so far on stress and whether

it's meditation or breathing exercises or journaling, whatever it might be, that is also potentially going to help, right? Absolutely. I mean, if you can even decrease the stress a little bit, and I forgot to mention it, but you know, it's also helpful for the parents of allergic children to decrease their stress. I mean, I don't know if people know this, but the parents of someone with a severe allergy have the stress levels of someone who just had a recent heart attack. Like it is a massive stress on not just the child or whoever is experiencing the allergy, but for the entire family. Yeah, that's so enlightening.

And I can already think of people in personal life and professional life where you can totally see that. So reduce stress as much as we can. That fourth pillar, sleep. Of course, if you're itchy and allergic, it is hard. But even just the idea that prioritizing my sleep as much as possible is going to have a meaningful effect on my allergies and how much I get bothered by them, how irritated I am, potentially how itchy, how many symptoms I get. So I think that's helpful around those four pillars. And then some of the other things, which I think are worth talking about, I always think about sunlight and vitamin D.

I know you do cover that in the book. I know we don't have long, so quick overview on vitamin D in outdoor living and its relevance for allergies? They think there's a connection. It's not quite clear, but there does seem to be a correlation between lower levels of vitamin D and immune function. I mean, we know that that's there, but it clearly must have an effect on allergies as well. So just making sure that you're outdoors in the sunlight more and and getting more vitamin d to support the basic immune health yeah is going to obviously have a knock-on effect for allergies exactly and my approach with patients is i always will try and optimize their vitamin d levels

even if there's no trial to say do do this on an allergic patient. I think there are some supportive data anyway on that, but it's again, this whole idea that there are multiple inputs going on. Let me try and optimize what I can. I can't optimize everything, but what I can. Okay. The next one for me is always pharmaceutical drugs. Could there be any drugs that we're using and taking that could be negatively impacted on microbiome? And so of course we've mentioned PPIs, proton pump inhibitors and acids. Again, maybe people can have a conversation

with their doctor or healthcare professional if it's something they want to try and get off. Potentially, we mentioned just to be cautious with antibiotics. As much as you can tolerate. I mean, the golden advice is, you know, if something extends past a week, that's a problem. People are just, they want to feel good as quickly as possible. So they go to their doctor on day

three of being ill and a virus takes about seven days to clear. So if you can just be a little bit more patient and go to the doctor later, you're kind of taking away some of the chances that you're going to get an antibiotic that you don't need. Yeah. And ask, what happens if I do nothing? Right. You know, and we have something in the UK called delayed prescriptions where we often, I'm sure many countries do, where we'll give them and say, look, you don't need to sort of cash this prescription in, but if these three things happen or one of them, sort of cash this prescription in. But if these three things happen or one of them, then it's time to start thinking about it. And again, the other problem is that we live in such a

litigation type culture that then there's a pressure on doctors and healthcare professionals to practice what we call defense in medicine. So they know if they've prescribed it and given that antibiotic, they can't then be sued for negligence. And that's another factor. If we're calling this a societal and cultural issue, we have to acknowledge that. So there's a bit of pharmacy scores. Then I always think about environment. And again, we've covered this, haven't we? I guess I've always had a bias to more natural things, more natural fibers, but we're now seeing that more and more, aren't we? Like the more natural your clothes, you know, eczema sufferers will know this, you know, certain synthetic clothes make it much worse and inflame their skin, don't they? So is there anything you can speak to about, I guess we've talked about chemicals and dishwasher stuff and sprays, but I guess you'd just say reduce them as much as we can. As much as you can. I mean, of course,

you can't not use them. I mean, we do have to keep things in check. Like you can't let dust mites run amok or you're going to develop a dust mite allergy, but maybe just cleaning with less vigor. Take it easy on the cleaning, you know, not- Just with water sometimes. Yes, just with water. Like, you know, look at your, there's no need, I mean, you'll hear this over and over again. There's no need for antimicrobial soap. Just soap denatures most bacteria. So you don't need the extra oomph. You don't need to nuke them. It's okay to use a lesser level of-

A bit more balance with our environment, right? Yeah. And advocate for clean air in your communities. Think about the types of things you're planting. That's another thing I like to tell people. So if you're gardening, you're planting. That's another thing I like to tell people. So if you're gardening, like, you know, spend a moment thinking about, is this something that's part of the natural landscape? Am I bringing in a tree that's not usually here? Because that could cause problems also. So just thinking about your little actions that you are advocating for your community. I know in the U. the US they're trying to, for years they only planted male trees because female trees are the ones that drop seeds.

So they're quite messy in communities. And so we overpopulated cities with male trees that are just pumping out pollen. So now they're trying to think about that. And in relationship to this new problem we have. It's so interesting, all these things that, and again, there's no malice here, I'm sure. It was just a case of... I mean, it makes sense. You don't want the mess. Yeah, exactly. So we can live our nice, human, clean lives, right?

We don't want the mess. Yet now we're seeing there's a consequence and it kind of makes sense these, are we bringing in non-native plants? I think you mentioned in the book about people who work with plants, botanists, and how often they are getting more and more allergies because of the repeated and concentrated exposure. I wonder, is there any research on people who work as cleaners? You know, are they getting more and more allergies? Because they're presumably surrounded by antimicrobials all day every day right them um people at like hairdressers because they're constantly around the dyes and the chemicals we use in our hair nail techs like anyone who's

exposed to substances of course you work in the medical field people develop latex allergies because they're constantly putting on latex gloves. So anytime we're getting repeated exposures in great dosages. So it's more and more people, especially this year, are developing respiratory allergies that never had a problem simply because the pollen loads are so great. And the pollen seasons, most places are extended because of climate change. So it's warmer for longer. And so plants are producing pollen for longer. So a lot of us are starting to get more allergic over time. You also mentioned about our modern desire for lush, green, grassy gardens and how that may be

contributing as well. Yeah. I mean, and it's, I mean, we haven't talked about meat allergy, the new kid on the block. I don't think it's here yet. You don't have the right tick, but in the U S we have a situation where we have a new allergy called alpha gal, and it's actually a sugar molecule that's found in red meat. So anything that, you know, deer, cow, pig, they all have alpha-gal. And what has been happening is that a tick will feed on a deer, get a little bit of alpha-gal, and then introduce it via a tick bite. You're out hiking, just enjoying your afternoon. A little tick, Lone Star tick specifically, bites you. And what's interesting about Lone Star ticks is their saliva produces an allergic reaction. So you'll get itchy with them. Like it's interesting about Lone Star ticks is their saliva produces an allergic

reaction. So you'll get itchy with them. Like it's almost like a mosquito bite and they'll deposit a little trace of their last meal. So if they just ate a deer meal and then they attach to you, they deliver just a little bit of that alpha-gal plus the saliva and it's creating an allergy to alpha-gal. So the next time you have a hamburger or a pork chop, you break out in all over body halves or get massively ill. So we're getting new allergies now developing that we've possibly never had before. And the connection to the nice lawns is that, you know who loves a good lawn? Deer. They're like salad bars for deer.

Well, even in like suburbia in America, deer are coming in. Absolutely. Yes. They just love a good lawn. And unfortunately, what they're tracking in with them are these ticks. And so there's- And then they tell their buddies, hey, hey, look, it's a great salad bar down this road. And so there's, it's this- And then they tell their buddies, hey, hey, look, it's a great salad bar down this road. Yeah. So you're getting this weird situation

where there's a tick that is in the neighborhood, plus the deer, and deer are proliferating because we don't like to kill them anymore. So they're everywhere. You have this lovely lawn that they absolutely adore. And so then you're getting more exposure. Potentially, you're just in your backyard sipping on a lemonade and there are ticks now in your yard because of the deer. And so isn't this just the perfect storm of things we're doing?

Is that happening on golf courses as well? Because golf courses are clearly hyper-artificial environments, lots of them anyway. I think all of them probably, you know, in terms of what is required. Maybe the Scottish links courses are a bit more natural. But I don't know, because you presumably need a ton of pesticide and fertilizer

to have them the way that they need to be for the game to be played. But I wonder, are we getting reports of deers now going to this big 18 holehole salad bar in America? Like, do you know at all? It depends on what type of grass you're planting and what bushes you have in your yard.

But some of those things are just delectable to deer and to other mammals. Like, so, you know, ticks can attach themselves to small mammals of all kinds, like raccoons. They're not picky, particularly. So if you're creating an environment that animals love, then you're accidentally tracking the ticks in.

And that's something we never could have predicted though, right? Like that's a scenario where you're creating a new problem for your body that really has only been around, I think it was discovered in 2010. So this is pretty new stuff. Yeah. I think we haven't mentioned, of course, you know, the book is such a thorough deep dive, right? It really is. I don't think I've read one that thorough, which goes into allergies and the whole history. So I appreciate how much work has gone into that, but we've not mentioned even things like air fresheners,

deodorant, oven cleaners, eyeliner, lipstick, shampoos. It is incredible once you start looking at what's in them and then you start to look at that list you mentioned from the environmental working group and how many chemicals are potentially linked to adverse health outcomes or certainly disruptions to the microbiome, right? And again, we've got to be careful not to scare people,

but I hope we've underpinned this conversation with empowerment throughout. So I'm certainly trying my best. I think you have as well. I think just knowing that this is the situation and knowing that your body is in these invisible conversations every day, not only will help you make better decisions,

but will help us as a society. Like I say in the book, and I mean it, there are some hard decisions we're gonna have to make as a group about how we wanna live and how we want our environments to be. And I think those of us who have allergies really understand the importance of making the right decisions, which is, you know, doing less and making changes, thinking not just about us and our needs, but about the needs of the larger ecosystems around us. And I think that's

something that speaks not just to allergies, but to the impending climate change crisis. So it's all intermeshed. I mean, if you want to think of allergies as partly about a climate crisis, you wouldn't be wrong. Yeah. So in terms of treatments, for people who are suffering with allergies at the moment, we've talked a lot about what they can do in their lives, but in terms of symptom relief, where are we? What's the current state of play with treatments? It's been really slow for us to really have any movement or development for many, many years. So treatments have stayed the same for the last 100, 150 years. So it's the first line of treatment for respiratory is antihistamines. So you can just cope with the symptoms and try to block that histamine response

we were talking about. They're fairly effective in mild and moderate cases, but they're not perfect. Some of them will do better and make you feel exhausted. There are newer ones that don't dry you out as much, so they're not as effective, but they don't make you drowsy. So it's kind of choosing between two options. Inhalers, so people will take steroids to control their negative response when they're having an asthma attack. And they will sometimes take a maintenance dose of something to beta agonist to calm their system down to prevent the attack in serious asthma cases or moderate asthma cases. So those haven't changed very much. That's been for a long time, it's been the same. And obviously people don't love steroids because again, it's a sledgehammer. It's just lowering your immune response. It was a big improvement. They used to take oral steroids for asthma,

if you can believe it, and it was terrible. So now with the inhalers, the direct dose in your lungs has been great for people. So it helps to control it. But again, it's not perfect. Yeah. And, you know, as we've already mentioned that they're not perfect. They don't work well for everyone. And of course, there are side effects. And the longer you're on them for, the greater the potential of those side effects. And I think something that's changed in our profession is, you know, there's always this sort of debate between topical treatments and systemic treatments. Okay, so a topical skin cream is not going to be as harmful from a side effect perspective as taking something through the mouth, which gets everywhere. But I don't think we can say, you know, I think we're learning more

and more that actually things get absorbed from everywhere. And one of the things that I think there is growing awareness of is something called topical steroid withdrawal syndrome, where people, and you can understand it, they're so itchy, they're in such discomfort and they've got that steroid there. It's so easy to keep putting it on. It doesn't matter what your doctor says with advice or anything, it's easy. And we're seeing lots of now problems from chronic use. Now I understand why people are using the creams so much, but it speaks to this whole idea that there's no perfect solution here, is there? No, especially, I mean, eczema for years was the worst one to treat because it was so hard to get

the skin to calm down. And steroids were great, except that they thin the skin. They can cause secondary infections. So they're not pleasant for the patients to be on. Many patients would tell me they don't want to take steroids. It's just, it's not, and they are afraid of the rebound effect. So once they stop the steroids, sometimes their eczema rash will get worse. And so they're in this continual cycle where they're taking steroids and then getting off them and then having to take them again. And there have been new drugs, like there's a drug called Dupixent, which is a biologic drug, and it's not a sledgehammer. It's working just on one of the mechanisms. And it seems to be a miracle drug, except that it's not. It also

causes conjunctivitis. It can increase the amount of esophonils in your body, which can sometimes trigger a problem. There's a special food-related allergy called EOE. It's esophageal, but it's involving the esophonils. So that could potentially lead to a problem. So there are some side effects, but it clears the skin beautifully. So they're finding some relief from that, which is nice, but that drug is also about $4,000 per month and you have to take it for life. So it really doesn't have an end point that we know of. I mean, it's an early drug, but we think they'll have to be on it continuously. And for food allergy, there is nothing really except for avoidance. There is immunotherapy that's, it is effective in certain cases, but not all cases.

So what immunotherapy is, is it introduces a small trace amount of the allergen and allows your body to over time slowly get used to the allergen. So you'll up dose every week and until you get to the limit where you can maybe have accidentally ingest a peanut and not end up in the ER with a response. And it's typically they do immunotherapy for the more severe allergies for that reason, to give people a little bit of leeway so that if they accidentally come into contact, it isn't going to be a lethal experience for them. And it does seem to be effective. But again, the maintenance doses have to be maintained. Like it's not as though we can cure allergies, which I think is really frustrating for a lot of people.

As to yet, we don't really have a cure because the cure would involve not triggering the immune system at all. I mean, all we're doing is coping with the symptoms once we have an allergy, but there's nothing that we have that will prevent you from developing one. And for someone who has, let's say, never had symptoms before, let's say something like hay fever, we're seeing this quite a lot, and they're

now starting to get it. And of course, we've discussed some of the reasons why that might be, how pollen rates are increasing. What's the advice now from chatting to all these world-leading allergy specialists, is there anything there? Should that person take some antihistamines for symptom relief? Does that increase the chances they're going to react more in forthcoming years? Should they not? If possible, just try and avoid it, try and just put up with mild symptoms. I mean, has that advice changed at all? it, try and just put up with mild symptoms. I mean, has that advice changed at all? Not really. I mean, luckily the newer antihistamines are pretty mild, so it's not terrible side effects. So that's why they're available over the counter. Like you can just take them as needed. So you don't have to take them every day. A lot of people will say,

especially if you haven't had allergies before, antihistamines oral, it's a systemic. So it's basically your whole body is getting a dose of antihistamine, but they're often now recommending that you do something like Flonase. So you're just trying to impact the systems in your nasal passages themselves or the allergic eye drops. So you're trying to stop the histamine reactions or tamp down the reactions where you're actually having it. So you don't get the drying effect or whatever else is going on from an oral antihistamine. So basically newer therapies are on their way. Yes. They're not without side effects. Correct. Hopefully this space will continue to evolve for symptom control. Nothing much has changed. Yeah. And the best research going on now is actually in that immune tolerance avenue. So there's a lot of research going on, like can we train or retrain the immune system once a problem develops that goes beyond immunotherapy? So can we somehow speed up immunotherapy and make it better?

So almost to reset your immune system, if that makes sense, to make it forget that memory that it has stored that oak pollen is bad. And so there's some really innovative research going on, but we're miles away. So I've been told we're at least 10 or 20 years away from any of that showing fruit. Wow. We started off this conversation with some quite worrying statistics

about how many of us around the globe are suffering with allergic disease. How many of us around the globe are suffering with allergic disease, how many of us will soon be suffering with some form of allergy. So to finish off this conversation, Teresa, are you optimistic about the future or pessimistic? Oh no, why did you have to ask me that? Oh no. Well, you've got a big smile on your face at the moment. I don't know what that means. Listen, I am just, I'm too steeped in public health. Like, I know that despite knowing what's good for us, do we always make the right decisions? And I worry that even if we know exactly what we're doing to ourselves, will we stop doing it? Because it's going to be inconvenient. It's going to force us to change things in a way that we'll temporarily will need to adjust.

and it won't be as convenient or efficient. It might cost us more money. We don't like to spend money unless it's on weapons. You know, we have priorities that don't track with the priorities that I think I've laid out in the book. And so I hope, I mean, I guess I'm like Mark Twain's cynic because if you scratch me, there's an idealist underneath that wants to believe that we'll do the right thing. But I worry that we won't. Well, I think you've written a wonderful book. I think despite all the doom and gloom,

I think it is empowering. And I think knowing this information is crucial if we're going to make individual and societal change. That's coming to the studio. Great. Thank you so much for having me. It was an absolute pleasure. Really hope you enjoyed that conversation. As always, do think about one thing that you can take away and start applying into your own life. Now, before you go, just wanted to let you know about Friday Five. It's my free weekly email containing five simple ideas to improve your health and happiness. In that email, I share exclusive insights that I do not share anywhere else, including health advice, how to manage your time better, interesting articles or videos that I've been consuming, and quotes that have caused me to stop and reflect. And I have to say, in a world of

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