Dr Jenna Macciochi: There's evidence that endorphins are really helpful in how the immune system works. So if you're going on holiday and you find that you might have if you have an autoimmune disease or an allergy or some kind of food intolerance, it might suddenly become a lot better when you go on holiday. And you just attribute that to eating a different kind of food, but it might be because you're happy when you're eating and it actually boosts these regulatory T cells that we have in our body that that sort of gently tap the brakes on the immune system and keep it in check.
Dr Rupy: Hi, it's Dr Rupy from The Doctor's Kitchen and we were going to continue with normal podcast releases this week and over the next few weeks. We've got pods on the ketogenic diet, reversing ageing, lifestyle factors for your brain, I mean a whole bunch of different subjects that I'm really, really excited to get into. However, we thought what better time than to re-release an episode that we've done with Dr Jenna Macciochi on immune health and what immune health actually means. There's a lot of misinformation out there at the moment and we thought, well, this is a perfect opportunity to remind people of just how incredible our bodies are. If you want some more specific information about SARS-CoV-2, the virus causing COVID-19, then I would direct you to the YouTube Instagram Live that we did. It's available on The Doctor's Kitchen YouTube channel, where we talk about specifically what we know about the virus thus far. It was recorded about a week ago or so, but the information pretty much stays the same at this point. Social distancing, isolation, and trying to minimise any contact is is really key right now. We, in this episode, we talk mainly about what immune health actually means, where it comes from, why it's not as simple as eating to boost your immunity, and what defines a robust immune system. We do talk about foods, lifestyle, and supplementation to support immunity and what that actually means and how they work, as well as clock gene, sleep hygiene, and why suppressing a fever may or may not be beneficial. It depends on the circumstances. So, what I would suggest is relax, take some time out to yourself. We've compressed this episode into one, so it's one long episode, everything to do with immune health. And one of the best things about this episode isn't actually the content, it's just how relaxed Dr Jenna is. I really love listening to her mellifluous voice. It's just a pleasure and it was an absolute pleasure to interview her as well. I do want to direct you to something super important, which is her book that just came out. It's called Immunity: The Science of Staying Well, and it is a wonderful resource for anyone looking to understand their immune health in greater detail. And she does talk about a whole bunch of extra subjects that we didn't get time to talk about on the pod as well. So it's things like supplementation, the evidence base behind stress-relieving techniques, and what things you can do right now to help you stay well. I think in these current circumstances, it's never been a better opportunity to really focus on yourself and look after oneself as well. So that's the reason why we're re-releasing, that's the reason why I think you should go buy this book, Immunity: The Science of Staying Well. And without further ado, please do listen to my wonderful conversation with Dr Jenna. And remember, you can find all of this information and more at thedoctorskitchen.com, as well as signing up for the newsletter where we give evidence-based recipes every single week, plus all of the lifestyle practices you need, particularly in this pressing time. Myself and my team are working even harder than usual to send you relevant content, rather, that will help you through this time. So, give us a five-star review if you find it helpful and enjoy the podcast. Welcome to the show.
Dr Jenna Macciochi: Thank you, Rupy. Thanks for having me.
Dr Rupy: This is, it's been a while since we've spoken, but we've finally got a date in the diary. And yeah, so I'm really, really excited about this episode. I've been following your work for a little while as well. And the first time we met was at my book launch.
Dr Jenna Macciochi: Yes, yeah, yeah. We have a mutual friend and I came along. I already had your book at that point. So it was nice to come and see you celebrate that moment.
Dr Rupy: It was a mutual friend of ours, John Payne, who's a photographer. And yeah, I remember him just saying, oh yeah, I brought my mate along. And I was like, yeah, that's cool. And then he told me you're an immunologist, you're interested in lifestyle medicine. I was like, that's amazing. That's great. And even back then, I was like, I think I must have said to you, we should get you on the podcast. That was back in January 2018.
Dr Jenna Macciochi: Was it that long ago? Oh, yeah.
Dr Rupy: We're here now.
Dr Jenna Macciochi: Finally made it.
Dr Rupy: So we know a bit about you. We know that your background is in immunology. How did you get into this space where you're interested in diet and lifestyle? Do you have a personal story? What's your background?
Dr Jenna Macciochi: I mean, I grew up in rural Scotland. So I grew up on a farm and I look back and I think, wow, that was a real privilege because it was very farm to table. And my mum was a professional cook. So she taught me how everything she knew about cooking. But it was also an area of like a lot of rural poverty. You know, there was a lot of industry closing, a lot of people that didn't have a lot. And I think that what growing up in that environment gave me was knowing how to cook and make something from nothing. And I think that's something that I think's been lost in today's society.
Dr Rupy: What, where abouts in rural Scotland was it?
Dr Jenna Macciochi: So it's in Ayrshire, in a farm. So it's on the west coast.
Dr Rupy: Oh, I don't know. I haven't ventured west. I've got to Edinburgh and I think that's about it.
Dr Jenna Macciochi: It's very wet. Yeah, it's beautiful. It's very wet. There's not a lot there. And we had a really small farm.
Dr Rupy: Sounds idyllic. I'm just imagining this farm to table food. Your mum's a professional chef. You're living off the land.
Dr Jenna Macciochi: Exactly. We're, you know, she taught me because because everything's quite seasonal, you know, we didn't have the variety of like exotic fruits and vegetables. It was really like what grew in that season.
Dr Rupy: I'm saying that Scotland's got some amazing wild fruits, haven't they?
Dr Jenna Macciochi: Yes, yeah. And like mushroom season, you know, we're all over that. Berries that I never see here, like tayberries. They're like these giant raspberries.
Dr Rupy: Tayberries. I've never even heard of that.
Dr Jenna Macciochi: Yeah. I just grew up thinking I was normal and then I came to down south and no one's heard of those.
Dr Rupy: I've I come across this forager, I think it must have been on a TV program, a cookery program, where he can mimic different exotic spices from all over the world, like coriander and Thai basil from herbs foraged in Scotland.
Dr Jenna Macciochi: Oh my goodness. I have to check this out.
Dr Rupy: I could look this guy up. I'll put it on the show notes, but it is incredible. And that that little snippet, I think it must have been on a Saturday Kitchen or something. That little snippet really made me think I've got to go to Scotland. I've really got to explore the different sort of culinary landscape.
Dr Jenna Macciochi: Yes, yeah. I mean, I think not always is the food is the first thing that springs to mind as being healthy. We have things like deep fried pizza. But I think intrinsically, the kind of real traditional diet of Scotland, you can find that it is is relatively good for you. And it's, yeah, follows the seasons. And my mum taught me a lot of how to process, you know, when you have all your root vegetables coming at the one time, how do you store that so that they last over winter and you know, how to just open your cupboard with hardly anything there and and suddenly make a meal from that. And I think those are great tools that that people need and perhaps have been lost a little bit.
Dr Rupy: Definitely, yeah. You like me had a mother who's really into cooking and food and and trying different sort of like types of cuisines as well. And that being instilled generation to generation, I think is something that is becoming less and less normal.
Dr Jenna Macciochi: Exactly. I can't help but think that there's something about the traditional way of life that we've lost. Like we very much were adapted to our environment because we had to be for survival. And it's kind of like the modern world is great, but have we thrown the bath water out with the baby? Or the baby out with the bath water? You know what I mean? It's like some of the elements of of how we used to live perhaps might be quite useful now.
Dr Rupy: Absolutely. I love using that evolutionary perspective. And I think that's going to definitely come into our conversation with immunity today. But taking that perspective of like, okay, what are we adapted for? And how do we manage the advantages and the benefits of modern living with how we are designed to live from a mental and a physical perspective as well.
Dr Jenna Macciochi: Exactly. I think when we unlock a lot of the secrets of evolutionary biology, it will yield a lot more in our understanding of why we are the way we are and then how to self-manage that to to fit in with the modern environment because that's not changing. You know, it's not going to go back to the rudimentary way of life anytime soon.
Dr Rupy: Exactly. I love that. And so you were based in Scotland and then you came all the way down.
Dr Jenna Macciochi: Yeah, so for some reason as a child, I had an obsession with health and disease. I was just really curious about. Maybe it was living on a farm, you see the circle of life, you know. When I was thinking about what to do when I left school, I'd heard about immunology and there was a course at Glasgow University in the medical school where they just do immunology and it's very select. There's only 20 students. And I just thought, wow, this sounds really interesting. This sounds like this is the foundation of health and disease. And when I got there, I was like, amazing. I've found my people. This is what I want to do. And that was almost 20 years ago now. So I've just been in the field ever since. And I love it. And I think there's always more to learn.
Dr Rupy: Your passion definitely comes through on your blog, on your social social posts and some of the articles that you've done as well for for major magazines. But let's get into it. So I think, and this is something we were talking about before the show, that the vernacular around immunology is very misunderstood and it's misguiding, I think, for a lot of people because you'll you'll find lots of articles like, you know, these are the top herbs to boost your immune system and you know, to to kill a cold and all this kind of stuff. So I think we should strip it right back and actually talk about what we mean by immunity.
Dr Jenna Macciochi: Yes, definitely. I think that's really, that's probably what got me, you know, talking about this so much in the beginning, just hearing so much misinformation. And I think that the first thing to say that the immune system is this huge complex web that's all over our body. It's found everywhere in the brain, in all of your organs, in your blood. And people like to think about it as being a single on-off switch. So you want to switch it on, fight infections, you know, create this force field that's going to keep you well and then switch it off again. And it's actually more like a series of different switches. And you've got to have the right combination. So it's a bit like a rheostat that you're constantly adjusting to get it just right. But then something in your environment will change, the season changes, and then you have to kind of tweak it again. So it's not just an on-off switch. I think that's probably a hang up from when people died from infection and that's maybe going back 100 or so years ago. Um, people might not make it to old age because they would die of infection that we don't see just now. So we're constantly thinking and we'll switch on our immune system, be invincible to infection. But it doesn't quite work like that. And um, it's important to say that immunity is what makes us unique. So it's almost like your fingerprint, even in identical twins, their immune systems will be different. Um, it's the way that the receptors are are recombined. There's a really unique way that the genes work to make the the sort of repertoire of what we call our immune cells and all the different things that they can sense, so viruses, bacteria. So every one of us is unique. And there's a kind of fundamental reason for that because, you know, if if you think about a room full of people and you you throw in a cold virus, if they were all to get sick to the same degree, we'd probably have died out as a species by now. So there's there's a fundamental reason why we're we're immunologically all different because, you know, some people might be more susceptible to bacteria, some of us might be more susceptible to certain viruses or parasites. But if we were all the same, we wouldn't have survived. So there has to be that kind of um, uniqueness in our immune system.
Dr Rupy: I love that analogy actually, because that does tease out a lot about how one thing might not work for some person, that could be diet, it could be medications, it could be any sorts of things. Um, and it might not do anything for the other person. And that uniqueness is something that I'm trying to bring out of people as well with the content I put out. It's about becoming the expert of not of health, of not of nutrition, but your own health and how that relates to you. So there's so much information out, so much content, but really it's about filtering out that content and and deciding how does that help me in this situation.
Dr Jenna Macciochi: Yes, exactly. And I think that's another, brings out another important aspect of the immune system is that it's always changing. It's not something that we're born with. I like to think of the immune system as something that's made. So you're born with a quite rudimentary immune system and you're reliant on a lot of what you've got from your mother, um, both through the placenta and then if you're breastfed. Um, and then your immune system really starts to develop from the moment that you're born. And it continues to develop and change throughout your lifetime into old age. So when people say, oh, I've got a really rubbish immune system, maybe at that moment in time because you've got a cold and you're feeling lousy, but, you know, it's not a fixed thing. There are things you can do to change it. And we know that only a fraction of what determines your immune system is in the genes. A lot of it is the environment, what you're doing. So things that you can actually um, be in charge of and manage by yourself. So nutrition being only one of those, but um, also all sorts of lifestyle factors.
Dr Rupy: Definitely, yeah. And we're definitely going to get into that. So your immune system is essentially this complex set of cells. I think a lot of people don't realise that anything that really protects you and helps your your innate sort of homeostatic mechanisms, your your balancing mechanisms is part of your immunity. So that could be the acid in your stomach. It could be your nasal hairs in your nostrils. Your mouth.
Dr Jenna Macciochi: Secretions on your skin. So it's it's cells, it's molecules, it's it's those barriers to infection. If you think about where you're normally going to get an infection, it's it's breathing things in or swallowing things or through the skin. It's the the bits that are exposed. And it's not just for infection. I think this is again something that people don't think about. Um, it's also the main thing that's involved in repair and adaptation. So if you're going and and working out in the gym, your immune system's helping your muscles adapt and repair and strengthen. It's involved in pregnancy and the success of of carrying a child. Uh, it's it's really a key part of the ageing process. It can really determine how well we age. And it's actually the main cancer surveillance that we have in our body. And I think that's again something that not many people think about.
Dr Rupy: Yeah. I I like to, I use the analogy in in the next book, Eat to Beat Illness, about how your immune system, instead of being an aggressive military force, it's like a peacekeeper. It's sort of like looking at where there needs to be a little bit more action, a little bit more force, and actually where we need to step back a bit. Because an immune system that is overactive, that is boosted, if you like, is not a good thing.
Dr Jenna Macciochi: No, exactly.
Dr Rupy: And that's where we lead to people who are suffering with autoimmune issues where your immune system essentially loses the capability to recognise friend from foe.
Dr Jenna Macciochi: Yeah, exactly. I think that's really important. The immune system doesn't just recognise different pathogens, as we call them, so the bugs that are causing infection, but they recognise danger and damage. The immune cells are intimately entwined with all our other systems in the body. So they have um, receptors for uh, your sex hormones, like estrogen, progesterone. So they're affected by different um, fluctuations in those. Also, they have receptors for stress hormones, like cortisol, and the neurotransmitters. So if you think about the complete picture, then how you're feeling, your stress, um, you know, the the different hormone times that um, maybe are going on, for example, in a woman's body, this is all affecting your immune system as well. So it's it's it's like the sixth sense, you know, it's really helping us um, manage our environment.
Dr Rupy: And and adapt to that.
Dr Jenna Macciochi: It's really quite amazing.
Dr Rupy: I think that's a really good analogy actually, being the the sixth sense essentially. And already just from that description of just how complicated and intricate the system is, you can understand why just taking a single supplement is unlikely to be the silver bullet that magically improves your immune system to fight off a cold or whatever you're going through at that point in time.
Dr Jenna Macciochi: Exactly. When I when I start teaching immunology down at the University of Sussex, the first time that the students get any kind of insight, I show them this huge web of all the the cell populations and the sub-populations and then like the sub-sub-populations. And you can just see, you know, the emoji of like the mind blowing. Um, because they're like, what? It's there's so many different things going on and so many switches um, that anything to do with the immune system is going to be multifaceted. So there's going to be a lot of different things going in to give you a certain result. So that's the reason that there's not going to be one single supplement or thing that you can do that's going to give you some kind of immune effect. It's always going to be multi-pronged in your approach.
Dr Rupy: That description of all those different sort of immunological factors brought back loads of painful memories for me actually in medical school trying to figure out, oh god, like all these different like T-regulatory cells and MHC complexes, like what is going on?
Dr Jenna Macciochi: Every year they discover a new subset or a sub-subset. And then there's like the complement system, which is like I actually had some people message me on Instagram and social media just saying, can she just describe exactly what a complement is? What is MHC? What are all these different sort of immunological factors? You know, it's quite funny actually.
Dr Jenna Macciochi: There's a lot of medical students I think that follow me and they're just trying to get like smarts for their essays. I always think I'm I've got to work really hard not to scare people off immunology in the beginning because it does get really interesting later on.
Dr Rupy: So now we kind of understand what the immune system is. And you're suffering from a cold at the moment.
Dr Jenna Macciochi: I know, ironically. Somebody said to me the other day, like, I didn't think you would get sick. You're always talking about the immune system. Surely you should be invincible.
Dr Rupy: And this is something I talk to patients about as well. It's like the very fact that you're sick, um, and you have a temperature and you are, you know, you have all these other sorts, you have a cough, you have a tickle, you have a throat sensation, shows you that your immune system is actually working.
Dr Jenna Macciochi: Yeah, exactly.
Dr Rupy: And it's about changing your perspective from one that is annoyed by the fact that you have a cold, which is I I get it, it's super annoying. But you should also be grateful and appreciative of the fact that your immune system is working. And not everyone has an intact immune system that can tolerate that. And you're most likely going to be fine in a couple of days.
Dr Jenna Macciochi: Yeah, that's the thing. Colds and flus are self-limiting. There's so many different varieties, which is why it's normal to get a few every year. And most of the time we don't even realise your immune system's working. I mean, we live in this really microbial world and every day it's just like fending things off. We don't even notice it. And every now and again, one might slip through the net and then you get sick. And the symptoms are actually your immune system more than the actual infection in most cases. So they might be unpleasant, but you just got to ride them out.
Dr Rupy: And this is again where I think like modern life is hard because, you know, the general message is like go down the pharmacy, buy all the over the counter medications and then get to work and struggle through the day. And um, if you actually maybe just took a day off or two and rested, you'd probably get over it a lot quicker.
Dr Jenna Macciochi: Exactly, yeah. Our producer is actually we're talking about some cold and flu over the counter medications. I was like, what do you reckon about this one? I don't I can't remember what it was. It was some spray for the back of your throat.
Dr Jenna Macciochi: It's really funny. Even though I tell this to my husband all the time, he loves himself one of those like, you know, the you put the hot water in and it's like a paracetamol based like decongestant thing. I'm like, that tastes disgusting. Save your money.
Dr Rupy: Yeah, I know, yeah. We'll talk about that actually with the the the fever sort of um, balancing medications and stuff. But now we know how complicated the system is and it's basically everywhere. Are there any particular sites where the immune uh, system will dominate?
Dr Jenna Macciochi: Yes. Well, I think the one that you can't escape is is the gut. Um, and I
Dr Rupy: It wasn't long until we're going to start talking about the gut.
Dr Jenna Macciochi: Exactly. You you can't not not um, talk about the gut when you talk about the immune system. They are completely dependent on each other. Um, and it's that dinner party fact of like, oh, did you know most of your immune system's in the gut? Well, it's true. And um, there's good reason for that. I think with a lot of things in biology, the the form follows the function. So the the the structure of the digestive tract, the whole architecture, it's optimized for digestion to get the most out of your food. That creates a vulnerability because it's actually the lining of your digestive tract is only one cell thick. So to me, that's like quite fragile. You know, there's there's all sorts of things going into your mouth every day. There's just the general bacteria and and bugs that are in our environment that we're swallowing. Um, there's things that could be in our food that could make us sick and just the food itself, how does the immune system know not to respond to that? So because of that, there's maybe about 70 to 80% of your immune cells that line the the digestive tract and they form all these kind of unique structures that have unique ways to keep a surveillance on what's going on. So that's really quite important.
Dr Rupy: Yeah, absolutely. I think that that sort of um, the the very fact that the architecture is only one cell thick shows you why it's so important to have immune cells there. Because we're in constant communication with our environment via our 30 cm long digestive tract, or the first part of it anyway. Um, and and that's why, you know, it's it's it's just a natural evolution as to why we have immune cells in those areas.
Dr Jenna Macciochi: Yes, yeah. And and, you know, I think it's such a portal for um, infection, you know, that we have to have those defenses there. It's interesting then to talk about the microbiome of the gut. This is getting a lot of airtime. People are getting more aware of the microbiome. And what we do know that if you do not have a microbiome, then your immune system does not develop. It's it's completely reliant on the colonization after birth of our microbiome to develop fully. So I think that's one another reason why we should take care of our gut microbiome.
Dr Rupy: Yeah. It's one of those reasons why we're seeing with uh, C-sections and versus natural delivery. Those babies who have C-sections are more at risk of having atopy, so allergic reactions and issues like asthma and eczema and stuff like that. Not to say that that's a definite, you know, it's definite case study that you're definitely going to get asthma, but you're certainly more at risk because of the um, issues with poor microbial development in the infant digestive tract.
Dr Jenna Macciochi: Yeah, exactly. And um, there's a lot of work trying to unpick those mechanisms because I think that's going to be really important to understand. That leads quite nicely on to the point that much of your immunity is actually set up in childhood. So many people who might be thinking, oh, I've got a terrible immune system, perhaps there are elements of what happened in those very early years that have had downstream consequences. And I think it's always helpful to think about what you can affect and, you know, instead of focusing on, oh, I was a C-section baby or I wasn't breastfed or these things, it's, you know, you can't change those. So it's better to think about what we can change.
Dr Rupy: Exactly. It's I have a lot of patients actually in general practice who uh, over the last 20 years of their life, and it might be young patients, 20 or 30 years old, they had recurrent illnesses as kids. And you can almost map a pattern with antibiotic use and C-section and not breastfed and all the other factors beyond just nutrition and medications that may have led to them having issues with their gut or issues with eczema, dry skin, and a whole spectrum of different diseases because of a poor microbial environment. That isn't to say that they are they're sentenced to that for life, but there are certainly things that we'll end up talking about about how we can actually encourage microbial development.
Dr Jenna Macciochi: Exactly. Yeah, you might just have a different set point because of those early events that happened because you're more or less sterile when you're born. Um, and then you're subsequently colonized as soon as you enter into this microbial world. And it's it's useful to think of it as, you know, the microbes were there before us. So we've evolved with them. We have to find a way to sort of have a a mutual relationship. So they actually do quite a lot for us in the gut. Um, they themselves are part of our immune defense. So we we talk about the microbial barrier. Because they out compete with any bad bacteria that could be coming in through the mouth and not giving them any space. Um, and they also make sure that those that delicate barrier of our our gut is really strong and really tight. Um, and this is an area of where I used to actually do a lot of research on when I was in Switzerland is this whole idea of leaky gut, which I think is one of those kind of woo-woo terms.
Dr Rupy: It is, yeah. It's it's it's weird because if you type in leaky gut into like PubMed, you you won't get much. But if you type in intestinal hyperpermeability, that's when you get, oh, okay, there is actually a lot of science behind this.
Dr Jenna Macciochi: Exactly. The science has sort of always been there and I guess the leaky gut term kind of existed in a parallel woo-woo world. And now the two are kind of converging and um
Dr Rupy: So you've actually done some research on this?
Dr Jenna Macciochi: Yeah, so that was a lot of the work when I I worked out in Switzerland, um, trying to understand, so I actually worked for a pharmaceutical company. I wasn't making drugs, but they employed me to try and understand what was going on in a normal situation in the gut in terms of the immune system to try and figure out, okay, what happens when that's perturbed and then can we intervene with something? So they were kind of hoping that I would give them some drug targets, but I was just like, oh, this is amazing. I can unpick the science, what's going on. And sometimes you have to know what's happening in a normal situation to know how that goes wrong.
Dr Rupy: And in a normal situation, those tight junctions that exist between these this one cell thick lining, they they increase and they decrease, right? They become more leaky and they become less leaky. But that's normal.
Dr Jenna Macciochi: And that's normal. I think that's a really important thing to point out because people can get very confused if they start Dr. Googling leaky gut. But it is a normal physiological phenomenon. There's actually certain um, components of our diet that can exacerbate that leakiness. Um, the two really well-known ones are are fat, in particular saturated fat, and the fructose from fruit sugars. But that's not to say that we should avoid those things because there's actually a lot of evidence that if you're consuming fat or saturated fat or fructose with fiber and with phytonutrients, that is actually fueling the bacteria in your gut, your microbiome, to produce particular things, short chain fatty acids being one of those, that helps seal up the gut again. So it's actually quite useful to open the gut when you're digesting food to facilitate the whole digestion and getting the nutrients into the body. And then the fiber helps to shut it back back up again.
Dr Rupy: So would you say it's less about having a leaky gut or having uh, permeability of your gut and more about the timing of how long you expose those tight junctions to be open essentially versus closed.
Dr Jenna Macciochi: Yes, I think that's the picture that's starting to emerge and that I think ties in quite nicely to dietary patterns, um, rather than focusing on specific nutrients. So, um, how many times a day we're opening up the gut. And one of the reasons that opening the gut up is is detrimental for the body is because the the microbiome that lives inside our gut can slip through those holes into the bloodstream and all around the body. And while those are considered our good bacteria because they live in the gut and they do a lot of good things for us, when they get in the wrong place, they're just the same as any other bad bacteria. They have the same molecular patterns on them that send an alarm signal to the immune system, they switch on inflammation. Um, and this can all be happening at a sort of low level that you wouldn't perhaps even be aware of. There's sort of no firm signs and symptoms of this going on. But I think cumulatively over a long period of time, then it could be that we start to see some some damage going on and and things springing up.
Dr Rupy: It's it's I think it's quite important for for the listeners to understand that um, your immune system is very much related to the inflammation response. And it's uh, essentially mediated by the immune system. So when you need to have uh, a response to uh, a bacterial infection, a virus, or even normal colonization of of your gut, um, it will elicit this inflammatory response. And I suppose it goes back to this timing. It's like, okay, you can have a little bit of an inflammation when you eat because that is very normal. But when you when you're eating for long periods of time, or actually when you're grazing or when you're having the wrong sorts of foods and it's this constant sort of exposure, that's when you have this low-grade inflammation, or meta-inflammation in the literature, that um, can lead to ill health outcomes.
Dr Jenna Macciochi: Yes, exactly. And I think that's another, brings out another important point about the immune system is that it's acute by design. So it's it's only ever supposed to be a short-term thing. And then if it's happening all the time, it starts to take its toll on the body and we we call it chronic. So it's a more of a long-term thing. But um, yeah, the the leaky gut thing, I think people shouldn't be concerned about. Uh, it's normal, but I think that you there's things you can do to prevent leaky gut. And fiber and phytonutrients are two of the proven ways that we know help tighten it up again.
Dr Rupy: Yeah, sorry.
Dr Jenna Macciochi: I was going to say, ties in quite nicely with some of the work that's coming out about time-restricted eating and consolidating eating into certain times of the day rather than the the snacking constantly because eating is is inflammatory. And again, that's normal, but you don't want to be doing it all the time because it's just another load that your body has to deal with.
Dr Rupy: Absolutely. When I talk about eating being inflammatory, it just raises a lot of alarm bells. Whenever I was like, eating causes inflammation. Everyone's like, what?
Dr Jenna Macciochi: I think about it everything through like this scientific lens. So to me it's it's normal because I know what it means, but I think when you say it to other people, they're like, you know, it's not that you shouldn't eat, but maybe think about how you're eating. Um, and again, I think it just plays into modern life. Like it's hard to sit down and have a meal. Um, and it's you know, everything is rushing, everything around us tells us to snack. I I lived in Switzerland for for a long time and I came back to the UK two years ago. And I was kind of like, this is just everything is pre-packaged into little things telling you that you need to eat on the go. And that that doesn't really happen in Switzerland. I found it quite a strange observation, like coming back to the UK and and you have to also think about the environmental impact of that because they're all wrapped in single use plastic. Do we need to have so many little snack bars and snack pots and you know, everything.
Dr Rupy: I think that's one of the many factors that could potentially explain the French paradox. So everyone looks at the macronutrient combination, oh, they have loads of saturated fat, they have loads of, you know, meat in their diet. But actually, they spend an hour for lunch. And this whole concept of grab and go sandwiches is just not there. And I think the process of eating and uh, the sense that they get uh, around lunchtime being their time is very telling for why they might have lower rates of uh, cardiovascular disease and and other things.
Dr Jenna Macciochi: Definitely. I I really noticed this in Switzerland, which again is a country that has um, um, really good health span. Um, and it's a it's a different setup to the UK, so you can't really compare, but um, I was working for a large company and they had this huge campus. Um, and at 11:30, the Swiss always started really early. At 11:30 every day, they troop down to the different restaurants and stuff on the campus to have lunch. And everybody ate together and lunch was like one hour, one and a half hours. And the canteen was only open between like 11:30 and 1:00. So you had to eat in that window. Um, and and you know, my colleagues were having like a rosti, which is like the fried potato covered in cheese with a fried egg on top, bacon, um, there'd always be some dessert or cake, then coffee. But it was like a whole like process. Everybody got away from their desk. And in the beginning, I found this like, I can't eat this for lunch. It's just like
Dr Rupy: Sounds like Christmas lunch every day.
Dr Jenna Macciochi: Exactly. Um, but you know, none of my colleagues were very unfit or, you know, looked overweight or, you know, everybody um, was very active as well. It was part of the culture and the lifestyle, but um, I think it's, yeah, the the snacking culture has not served us well. And it's hard to kind of put your finger on what it is about it, but I'm really convinced that this is not um, helping us in some sense. And if we can get back to something a bit more traditional, a bit more boring, maybe it's going to be a bit useful.
Dr Rupy: I think using that evolutionary perspective about around time restricted eating or as I like to call it, defined periods of eating. It sounds a lot a little bit less intrusive and a little bit less like, you know, restrictive. Exactly. Uh, but uh, some really interesting research coming out from uh, the West Coast of America, uh, looking at time restricted feeding where you don't change the calorific content of your food at all. You just change when you eat it. It's a very actionable tool for a lot of people. And it's something that I talked about in my first book, The Doctor's Kitchen, but also my second book, Eat to Beat Illness, where, you know, that as a principle of healthy eating, just the timing of food is something that could potentially have very good effects.
Dr Jenna Macciochi: Yes, exactly. I think we're just so over the time of restriction. Like adding that restriction onto your life if you're trying, oh, I'll only have this really low calorie salad that's not going to satisfy me for lunch and leave me just thinking, oh, I want to eat all the food all afternoon. I think that it's not it's not been helpful and we have to move away from that and start enjoying food. Definitely in terms of um, the immune system, there's evidence that endorphins are really helpful in how the immune system works. So if you're going on holiday and you find that you might have if you have an autoimmune disease or an allergy or some kind of food intolerance, it might suddenly become a lot better when you go on holiday. And you just attribute that to eating a different kind of food, but it might be because you're happy when you're eating and it actually boosts these regulatory T cells that we have in our body that that sort of gently tap the brakes on the immune system and keep it in check. So I think there's a lot to be said for like, you know, how you're feeling when you're eating and what you're doing in your day-to-day life. So managing the stress.
Dr Rupy: Even on an anecdotal level, like, you know, I have patients that come in and they're they're they're stressed at work, they're working long hours. Uh, obviously there's there's loads of confounding in the fact that they're probably reducing their sleep, they're probably not eating right. But certainly stress uh, having an impact on the likelihood of you having or suffering a viral illness is certainly there in my opinion.
Dr Jenna Macciochi: Yes, definitely. Yeah, no, there is there is evidence to to suggest that. I mean, in the short term, actually stressors are quite useful for the immune system. They clear out a lot of inflammation and they can actually get rid of a lot of old and aging cells and give space for new cells because we have this concept in immunology of the immunological space. So you can only have so many immune cells in your body at one time. And as we get older, they start to age. You want to get rid of some of the old ones, bring in some of the new ones. And stressors like running away from something and and um, or some really short intense exercise or something that's quite stressful but very acute, that can actually be quite beneficial for the immune system. But when it becomes either a chronic long-term stress, so you have to care for a sick relative or um, or short intermittent stresses, so lots of frequent times when you're becoming stressed, it's maladaptive. So the immune system becomes less responsive to that cortisol effect and you lose the benefits of sort of more acute stresses to the overall health of the immune system.
Dr Rupy: I've um, I've been coming across a lot of research looking at um, fasting as well as uh, time restricted eating and its impact on the immune system through the lens of not only um, autoimmune issues and uh, diabetes in terms of therapeutics, but also cancer as well. Um, which I think, I mean, first to caveat it, it's a there's very small research studies. It's it's very, it's not uh, practice at the moment. It's not in um, uh, first line practice. And obviously a lot of people who have issues around eating, disordered eating shouldn't certainly not engage in any fasting practices. Having said that, it is quite interesting from an immunological perspective.
Dr Jenna Macciochi: Yes, definitely. I think the research coming out is really exciting and I'm really curious to see how that evolves. Um, it is very experimental at the moment, but again, fasting is considered another stress on the body. So the immune system is highly dependent on all nutrients. Um, so all the macros, it needs proteins, um, carbohydrates and fats, and all your vitamins and minerals. These are all necessary to help the normal running of the immune system. And they're really good at sensing nutrient status. So they they know what's going on and they can respond appropriately. And different nutrient sort of profiles in the body or metabolic profiles can seem to influence the fate of immune cells to go down either more regulatory paths or more inflammatory paths. So it seems to be like manipulating that could help um, redirect the immune system away from being quite uh, an autoimmune phenotype. So help people with that. Also, uh, fasting in itself will kill off any vulnerable immune cells. So as they age, they're more likely to go wrong. Like anything with time, you know, as your car gets older, it's more likely to be a bit faulty. And um, sometimes there is a time where you just, you know, it's it's time to change the car. It's time to change, yeah, exactly. Get rid of that. And and things like fasting, so reducing nutrient availability makes those kind of older cells a bit more vulnerable and they're more likely to pop and um, go through apoptosis, which is this process that removes them. And then you have more space to repopulate uh, with new immune cells.
Dr Rupy: I I like this because there's lots of arguments for and against it, right? So the process of fasting upregulating autophagy, which is the self-regulation where you clear out the old dead cells, senescent cells that are sort of like hanging around, they're not really doing much, they're not really functioning, but they're and they emit like mild inflammation signals and you know, that that can so clearing that is is great. And then also going back to what we were talking about where you essentially give your gut a break from digestion, the tight junctions, that can also reduce your immune cell response. But then also conversely, if you're not eating, then your bacteria are not being uh, provided with a food source and they could uh, essentially start damaging the lining of your gut.
Dr Jenna Macciochi: Exactly. I think it's finding that sweet spot and we don't we don't know what that is. Um, yeah, so the I think the microbiome is a really important point because your your gut is lined with mucus, which is essentially like a kind of carbohydrate source for. So if they haven't got any food, eventually they just start eating the mucus, which is part of our defense. It's a barrier. And then once that goes, your gut lining is more vulnerable. But there's definitely a window whereby fasting is having the beneficial effects before it tips over into the um, more negative effects. And there's a lot of speculation as to how many hours or days that you should be fasting to give you this sort of reboot. And I think the truth is that we don't know conclusively and and we're not able to sort of dish out that um, to patients or the general public yet. But I think there's a lot of trials and a lot of a lot of things are going to come out.
Dr Rupy: There's a lot of self-experimentation I'm finding of researchers themselves who are trying to experiment with with fasting. I haven't done it yet myself, but I'd be super interested to see what the effects are, but actually conduct it like an experiment. So measuring my uh, my vitals before and after and some inflammatory markers and the rest of it. But I think it's going to be really, really hard uh, just looking forward to demonstrate what the sweet spot is for the general population.
Dr Jenna Macciochi: It might be quite a unique thing, individual to the person. The age of the person might be quite important as well. So
Dr Rupy: As far as and that's before we even think about like the mental health impacts as well of like declining yourself to have food when there's so much food around. And that that could potentially for certain people serve to increase your cortisol response, increase your stress around food and actually lead to an overall negative effect, which is something you have to balance. But uh, that's why I'm just a big fan of the defined eating periods.
Dr Jenna Macciochi: Yes, yeah. I mean, that's something I've been doing for quite a long time now. And I do it with my kids as a practice of getting them used to knowing what a meal is, that we sit down and we enjoy our food and we talk and it's it's family time. Um, rather than being like, oh, you you only eat at these times of the day, but they know what breakfast, lunch and dinner is and gently kind of um, not put them in a situation where they think it's normal to snack all day. So it's just and making mealtimes like a happy time that is for family.
Dr Rupy: Because there was this myth, wasn't there? Like, you know, if you graze a little bit throughout the whole day, it'll increase your metabolic energy and it'll reduce your weight and all the rest of it. But generally what I mean by defined eating periods are anywhere between 10 and 12 hours in the day where those are the times when you eat and everything around that you try and keep clear. Obviously within reason. For example, today's Friday, I'm going to go out for dinner with a couple of my friends that I haven't seen for about a month. And uh, we're going to eat.
Dr Jenna Macciochi: Yeah, exactly. Yeah, Wednesday night I had a Christmas party and, you know, I was eating dinner way later than normal because I normally eat with my kids, so it's quite early that they have dinner. But you know, that's that's the thing, the beauty of doing everything most of the time that you've got that buffer for, you know, when you let your hair down and it's interesting recently I was writing an article around this whole hypothesis about the inflammatory load of the gut and um, I was trying to find out why we have these guidelines to eat little and often and this dogma that is really in people's heads that they can't go more than three hours because, you know, like something terrible will happen if I don't get food. And I was trying to figure out where that had come from and what it was based on. And most of it was just kind of assuming that we could stabilize insulin levels by, you know, having the food kind of little and often. And there was no sort of hard fast evidence on any other reason or why that sort of evolved. And it's just one of those things that people must have thought, that seems sensible. And no one ever stopped to think whether that is actually the best guideline.
Dr Rupy: That's really strange because actually, if you look at some fasting studies, and I think they go back really far because it's quite unethical to to maintain fasting for these patients. But they would go weeks and weeks of of just not having any food. And they were maintaining a glucose level because you essentially go into a state where you start burning your fat. But then when you're running out of fat, you're also burning your protein. So you're maintaining a glucose level because glucose is fundamentally one of the most important uh, fuel sources for all of our cells in the body. So even if you're not taking in glucose, your body is still adapted to having a glucose level. So this whole process of like eating little and often to maintain a glucose, it's an insulin level that's low, like doesn't doesn't seem to make sense.
Dr Jenna Macciochi: And then you think, well, if I if I haven't eaten, then I I have energy stored on my body. My body just needs to know how to use it. And that's an adaptation and that, you know, it's something that you need to to be able to do. And yeah, I think we've kind of lost touch with our intuition about eating. I think something I definitely noticed moving back from Switzerland to the UK. There everything felt quite intuitive. Um, you know, people are eating these huge lunches. And I remember saying to my colleague Sven, like, you know, what do you what do you have for dinner? And he's like, well, you know, in winter, I'll have maybe a soup. And then in the summer, maybe a salad around like 5:00, 6:00 when he got home. But he'd had this huge, huge lunch. And there was there was nowhere to snack in the in the whole campus. You know, there was maybe one or two vending machines that you could find somewhere in, you know, that would have food available. But the restaurants and the canteen were just literally open during lunch and then shut again. And it was kind of just like, that's normal because that's lunchtime. And there was not the kind of um, grazing.
Dr Rupy: It's definitely not like what it's like here. There's like 10 stores where you can get any sorts of food.
Dr Jenna Macciochi: I know. So you have to cut through the noise and think, what are my needs? Do I need all these little plastic pots of snacks all the time? Or, you know, can I wait till lunch and have something substantial that's not going to make me feel like I want to eat again before dinner.
Dr Rupy: I think it's a very good perspective. It's kind of like, what do they want?
Dr Jenna Macciochi: Exactly, because our digestion is actually quite basic. And then the bacteria are digesting a lot of it for us and liberating a lot of the nutrients for from us. So your diet could be amazing, but your your microbiome is not all there because of past antibiotics or whatever. And um, you won't be getting the best out of your diet. So it's worth kind of, you know, as a long-term strategy, really trying to nurture that, I think.
Dr Rupy: Do we have to completely ban sugar to improve our immunity?
Dr Jenna Macciochi: Oh, that's a tricky one. Yeah.
Dr Rupy: It's a tricky one.
Dr Jenna Macciochi: I think you've got to think about overall dietary pattern. Um, I as I mentioned before, we know fructose has quite a dramatic effect on the gut barrier. That's a fruit sugar. But that can be quite easily counteracted with lots of fiber in the diet.
Dr Rupy: Which you naturally have in a whole piece of fruit.
Dr Jenna Macciochi: Yeah, if you're eating fruit. Yeah. So you kind of have to think about how you're eating overall. Um, the active part of the immune system that's fighting infection, so we have sort of the active and the more regulating part, it is very glycolytic, so it it loves sugar. It uses that to fight an infection. That's not to say that eating sugar is going to cause that, but when you already have an infection, um, there is actually some evidence, you know, the old adage of um, feed a cold, starve a fever, because a fever is a much more aggressive immune response. Um, they did do some experiments to look at that and they found that the reason that you might want to not eat when you have a fever is to maybe just tap the brakes on the immune system because um, you're just withholding the glucose and and maybe that's stopping it being too aggressive and stopping you feeling really, really sick. So but again, that's, you know, over a really short frame of time that, you know, not a long-term thing. So yeah, think about the whole picture with sugar.
Dr Rupy: It's going to be the whole picture. Yeah, I know. I'm not I think it's I think it's uh, we run the risk of demonizing one particular macronutrient. And um, I just think it's it's quite short-sighted. And you know, sugar is one of the most important molecules in the body. Glucose and it's different monosaccharide forms. So I also think, you know, at this time of year, it's it's it's sharing fun times with colleagues and friends and family. And that's tapping into the endorphins, which is also important for your immune system. If you're stressed about trying to avoid sugar when we're, you know, you're literally walking down the street with quality street and chocolates and mince pies, then, you know, that stress is not, you know, you have to sort of look on balance what's important.
Dr Rupy: If somebody is on immunosuppressant medications, what should they do to support their immune health?
Dr Jenna Macciochi: I think definitely, um, find out if you've got any gaps, um, any deficiencies in any of the key vitamins and minerals. I think vitamin A and vitamin D are quite important for the threshold of the immune system. Again, um, taking care of the diet, there you might have a little bit more need for things like vitamin C. Um, but it very depends on if you're deficient or not. And one of the best ways actually to avoid infection is um, good uh, hygiene and and staying out of places where you know there's going to be infection. People kind of underestimate that, but um, yeah, that's probably uh, a real uh, key thing to avoid it. And and movement, so getting the lymphatic flow going uh, and really good sleep because um, sleep really uh, is detrimental to the natural killer cells. These are our real viral and fighting cells that we have in the immune system.
Dr Rupy: We haven't talked about sleep actually, but there is a question about how sleep uh, impacts immune health.
Dr Jenna Macciochi: Yeah, there's massive um, changes happen when we sleep in our immune system, which is really, really cool. We have quite a lot of inflammatory cytokines go up in the blood, but the cells go down and a lot of new cells are being produced and redistributed. Um, and there's a lot of draining of of all the tissues and the lymphatics. So it's really quite an important restorative time, particularly if you've been sick, um, giving yourself time to rest and and get that sleep is really important.
Dr Rupy: Which is why I suppose when you get circadian rhythm disruption from travel or from night shift work, and there's loads of questions about night shift workers as well. Uh, why that actually might lead to recurrent infections or a general sort of fatigue and the whole plethora of other things that are happening.
Dr Jenna Macciochi: It's really interesting actually, when you start to look at circadian rhythms in the immune system, it's like maybe about um, 80% of the immune system genes are under circadian control, but not all of them. And it's there's a lot of work to try and unpick what aspects of the immune system are and are not under circadian control and why that might be. So it's definitely emerging and we know that circadian disruptions leaves you open to infection.
Dr Rupy: Should I take vitamin D to improve my immunity?
Dr Jenna Macciochi: Yes. Well, again, vitamins to sort of plug deficiencies. So it is likely if you live somewhere like where we are now in the UK, that in the winter, you might get deficient in vitamin D. I think it's worthwhile getting checked. Vitamin D is really important to the immune system. And not in a boosting fashion, but it actually regulates and and, you know, keeps the brakes on the immune system. Um, so it could be worth supplementing if you think you could be deficient. Uh, but it works hand in hand with so many other things. So it needs vitamin K as well, and it needs magnesium. So you kind of make sure you're getting those other factors into your diet. Interestingly, vitamin K is mostly produced by our microbiome. So make sure you're feeding the microbiome. You can see it's like a whole cascade of events.
Dr Rupy: Everything always comes back down to the microbiome. I remember I was I was meant to be doing my nutrition medicine master's paper and one of the essay options was uh, vitamin D and discussing the role for vitamin D supplementation in the UK. And I chose not to answer that because it is so broad. And I already had 1200 words. And it's so broad to go into all the different pleiotropic effects of vitamin D because it's not a vitamin, it's a hormone and a master regulator of hundreds of different genes. And you're like, you can't even begin to imagine how important this thing is.
Dr Jenna Macciochi: The immune cells, most of them have vitamin D receptors on them. So they're directly responding to vitamin D and then it's really changing their behavior and stuff. So yes, um, if you think you could be deficient, I think it's one that it's very hard to get from diet with vitamin D.
Dr Rupy: Dr Jenna, this has been a mammoth session.
Dr Jenna Macciochi: I know.
Dr Rupy: I think it's the longest pod we've had and we're not even half of the way through all the different things we should be talking about. We need to talk about inflammation in more detail, brain, lymphatics, all those different things.
Dr Jenna Macciochi: We can do a part two.
Dr Rupy: We'll have to do a part three, four, five.
Dr Jenna Macciochi: Just indulge me because I I could talk about the immune system all day, every day.
Dr Rupy: Your passion certainly comes through. It's been an absolute pleasure and we'll catch you another time.
Dr Jenna Macciochi: Yes, thank you very much.
Dr Rupy: I hope you enjoyed that podcast. Uh, Dr. Jenna is brilliant. She uh, is, you know, she's a a lecturer, she holds a PhD from Imperial. She's got uh, a whole bunch of the right credentials, but she also has a gift in that she's able to effortlessly um, express the complicated science in simple terms so that people like myself can understand it better. Um, you know, I've been studying uh, medicine for a number of years and I continue to learn more and more um, from people like Jenna and and other people in this space. Do check her out on socials. She is providing a lot of up-to-date materials, particularly to do with the outbreak, but also generally as well. Um, check out her book, Immunity: The Science of Staying Well. It's a fantastic resource. I can't recommend it enough. It's brilliant. Um, and it gives a bit more detail and structure to the conversation that we were having today or when we released it. Um, and uh, yeah, I I I think to summarize our conversation, polyphenols are going to be your friend. So trying to get variety and different colours in at every single meal and the different types of colours represent different uh, phytonutrients and benefits to your overall well-being. So trying to get the purples, reds, greens in is fantastic. Looking after your gut health and we nurture them with different types of fibres. So chickpeas, lentils, all the store cupboard essentials that hopefully we're going to be consuming more of over the next couple of weeks and think about how that helps you from an immune point of view and an overall well-being point of view. And the other thing are things like nuts, seeds that provide quality fats along with extra virgin olive oils and all the different cold pressed quality oils that we have that actually have anti-inflammatory effects and can potentially improve your immune health as well. Uh, I'd also say things like uh, lifestyle practices. So right now, which is a terribly anxious and anxiety-inducing time, it's never been a better time to try and practice gratitude and living in the moment and uh, being present. And I know these sound a bit woo-woo, but actually all it involves is reducing your um, your news and um, your consumption of media articles, which I agree is very hard to do right now. It's taking moments to uh, focus on your breath, even if it is for about 60 seconds, and trying to try different uh, types of meditation as well, because we know that they can have benefits to not only your anxiety levels, but also your immune health as well. I hope this has been helpful. Um, and we will continue to uh, release podcasts on the normal schedule if we feel it's appropriate. If there's anything new or anything else that you want us to try and cover, we will try and do that as well within reason. But there are a lot of resources out there, including the NHS website, the CDC website, and Dr. Jenny Macciochi's um, socials as well. Give us a five-star review, sign up to the newsletter at thedoctorskitchen.com, and I will see you here next week.
