ZOE Science & Nutrition - Recap: Tips for a healthy immune system | Jenna Macciochi

Episode Date: November 11, 2025

Today we’re diving into our immune health. You can think of your immune system as your body’s personal physician. Diligently working around the clock to monitor, detect, and repair anything that might disrupt your health. However, because it’s work is so seamless and silent, we often take it for granted.  So, how can we better support our internal MD? Immunologist Jenna Macciochi joins me to explore how simple, everyday actions - from what we eat to how we breathe - can profoundly enhance our immune health. 🌱 Try our new plant based wholefood supplement - Daily30+ *Naturally high in copper which contributes to normal energy yielding metabolism and the normal function of the immune system 📚 Books from our ZOE Scientists: The Food For Life Cookbook by Prof. Tim Spector Food For Life by Prof. Tim Spector Every Body Should Know This by Dr Federica Amati Free resources from ZOE: Live Healthier: Top 10 Tips From ZOE Science & Nutrition  Gut Guide - for a healthier microbiome in weeks Have feedback or a topic you'd like us to cover? Let us know here Listen to the full episode here

Hello and welcome to Zoe Recap, where each week we find the best bits from one of our podcast episodes to help you improve your health. Today we're diving into our immune health. You can think of your immune system as your body's personal physician, diligently working around the clock to monitor, detect and repair anything that might disrupt your health. However, because this system is often seamless and silent, we can take it for granted. So how can we better support our internal MD. Immunologist, Jenna Machoki, joins me to explore how simple everyday actions, from what we eat to how we breathe,

can profoundly enhance our immune health. If I asked you to say, like, where is your digestive system? You could probably point to the location on your body. If I ask you to point to where your immune system is, you might not know where. I'm literally like, I don't... Yeah, but that's because it's everywhere. Okay.

from your brain to your big toe, it's absolutely everywhere. And that's because essentially it's helping keep your body safe. So it has to be everywhere. It's really enriched at the barriers to our body. So, you know, under your skin, because that's exposed to the environment, the lining of your nose, the lining of your mouth, all the way down your digestive tract, you have huge numbers of immune cells that are fortifying those barriers because those barriers are very delicate. So the airway lining and the digestive track lining, they're very delicate and that serves a function that helps us exchange oxygen when we breathe. It helps us digest our food and absorb nutrients. But we need to have that extra fortification because that's vulnerable. You know, we can inhale germs or swallow germs and that could make us sick. So you will find immune cells everywhere. They're also swimming around in our blood. So they're performing a kind of surveillance function. And then you have immune organs where they'll like congregate and do. a certain function. So we have lymph nodes which are all over our body and they're all connected with the lymphatic system. That's kind of like your blood circulatory system, except it doesn't

rely on the heart to pump it around. So it relies on your muscles moving. And the lymphatic system is going to squeeze those immune cells around allowing them to circulate all over your body. And they pass in and out the lymph nodes and that's a place where they can meet and talk and do various functions. It's a beautiful picture I'm starting to think about all it's around me. You've mentioned the word immune cells quite a lot when I've asked, what is the immune system? Is the immune system like a set of immune cells? Yeah, immune organs, lymph nodes, spleen, bone marrow, and the molecules that they're producing to communicate with each other. So you've got cells, molecules and then organs. What can you do where you feel there is really strong evidence that is really going to make a

difference? Have that long game in your mind. You know, we live on average. to 80 years old, but our health span is 60 years old, and that's a delta of 20 years. And it's really emerging that the immune system is the key element to closing that delta. What you're saying is that you might only have 60 sort of quality years, and then you're saying you're going to 20 years when you're feeling quite sick, and you're saying the immune system you think is the most important thing for trying to make that a shorter period of time. Yeah, exactly.

And the things that are going to help that are also the things that are going to help you get through winter in terms of the sort of more short term feeling well and less downtime. And to me, the biggest piece of advice I can give to anyone in terms of diet is to follow a really anti-inflammatory diet pattern and stop hyper-focusing on superfoods. You know, if you eat five or six superfoods on repeat, that's not going to be as beneficial as a really diverse dietary pattern that's anti-inflammatory. And I often reference the Mediterranean diet only because it's the one that's perhaps the most studied and has the largest volume of evidence behind it. But it's bringing in all those elements. So a variety of fruit and veg using really good fats like olive oil, lean protein,

oily fish and fiber, making sure those gut bugs are fed and happy right from the outset and and across the life course because that's not only going to be supporting your immune system, it's going to be minimizing that unwanted inflammation that's going to be sort of taking energy away from your ability to fight infections. It's going to be reducing the driving of those hallmarks of aging. It's really, really important, I think, that the overall pattern of your diet is considered rather than like, you know, we want to think of one or two superfoods, one or two supplements that we must take. And Jenna, can I ask you a question about that? So I follow my you know, the guidance I get from Zoe in my app every day. And there'll be a lot of people listening

who are members. And one of the things that has been most surprising to me, and I think it was quite surprising to, you know, my co-founded inspector and a lot of the other scientists is the health outcomes we're focused on were a lot about improving long-term health. But one of the things that's most surprising, actually, when we look at the results from the random and clinical trials is how many people feel much better very rapidly after just a few weeks. Yeah. And one One of the avenues that the scientists are sort of investigating is this idea that it's sort of the microbiome affecting the immune system that could be affecting how you feel. Yeah. I mean, is that what's going on?

What do you think? I think there's a really strong hypothesis there. One area that I used to work in was the gut barrier permeability. So how leaky and permeable the gut barrier is. And that happens. There's a natural physiological response every time you eat that you experience a certain amount of leakiness. and that's normal and natural and it's part of the digestive process

but when you create any sort of leakiness in that barrier you're going to get bits of whatever's on the inside of your guts or microbes and bits of microbes and whatever else leaking into the body and as soon as they're in the wrong place they become a problem for the body and when there's a problem for the body

the immune system's going to be alerted and it's going to turn on inflammation so you get this post-pranile inflammatory response, which in a healthy individual, when it's happening in a really normal physiological way, is completely fine. But when we have a gut barrier that's not really robust because perhaps the gut microbes are a bit out of whack, because of poor diet or medications, that barrier is already going to have more leakiness than it would normally. And the inflammation is going to be increased and that burden of inflammation if you think about across the life course

is going to have an effect on all the things that drive ageing. And I think this is what we have to think about when we're looking at that sort of long-term health picture. And do we understand, because I started leading with this other question around like how it makes you feel, like the mood and energy. Is that back to the way this immune system can have this for, you know, you're described about illness? Is that linked? Is this something completely different? It's completely link because inflammatory molecules that are being produced, as we spoke about before with the sickness behaviours, are going into your brain and they're acting on your brain and they're making changes in how you feel. And we even know now that there's a subset of people with mental

health conditions that respond to anti-inflammatory interventions because it's like a tough form of sickness behaviours. So the response that we have when we have the flu that's meant to keep us lying on the sofa recovering is happening at a sort of low grade level and making people feel depressed and have per mental health. When I'm sick, I feel low. Like, it definitely affects my mood. I very rapidly, I'm like, I'm going to be sick forever. I'm never going to feel good. I just feel bad about everything we're old. Like, that's a real thing that, like, my immune system is doing to me. It's not just, again, if I just had a better stiff upper lip, like my, you know, My parents and my grandparents, I would...

I mean, there might be some people who can really, like, dig deep and, you know, push through that. But it is a real physiological response driven by your immune system, communicating with your brain to adapt your behaviors. And so this is an example of how it really can be true that the food you eat can genuinely change your mood. Yeah. And why some of the terrible ultra-processed food we might be making us feel bad, but also how if you could shift that diet, which I guess is what we're trying to do with Zoe membership and with... with this podcast, you can see the explanation for why we see this shift in mood quite fast. Exactly, yeah.

I would like to talk about stress. What can you do that could mean that you actually have an impact on your immune system by somehow reducing your stress? Is that possible? Yeah, this is probably the one I find most tricky from a very personal level because, you know, there's a lot of different stress-reducing techniques, But often these are kind of adding another layer to the life load. So I would say everybody needs to acknowledge the importance of stress as having this impact on your physical health. Don't think of it as something that's in your head and start to develop an awareness of stress and how it might be impacting your health. Often it's the last thing we come to. We'll audit other areas of our life. We'll audit our diet or sleep or exercise. And sometimes actually well, wellness becomes a stress because people are trying to do things perfectly. I speak to a lot of people

who see advice online and they can't quite apply it to their own life because perhaps it's been a bit misdirected and that too becomes a stress. So I think it's really like remembering to put things in context. And I like to break it down and think of, you know, you have to have some in the moment stress tools. So if you, you know, have a really difficult meeting at work or a difficult phone call, you know, what can you do in the moment? And for me, it's things like getting outside, like widening the gaze. So we spend a lot of time hyper-focused. And because our eyes are part of our brain, you know, when we change the gaze, it's giving signal to the brain that, you know, you're more relaxed when you have this broad view on the horizon rather than the

laser-focused looking at a screen. So you're literally saying, like, put the phone away, walk into the garden, and that actually can affect your stress? Yeah, can affect your stress. I mean, we're talking like little minute things but it's all going to add up there's not just one lever that we're going to pull so we've got it in the moment things altering your breathing you know so when you are inhaling your diaphragm's moving down your heart has a lot of space the blood flow is going to go faster this is going to give a signal to your brain that you have to slow the heart rate down and then you exhale and so you have this thing called the respiratory sinus arrhythmia so it's a constant interaction between the heart and these sort of mechanoreceptors telling your brain when you need

to speed up and slow down the heart rate. And Jenna, you're a very serious scientist. I just want to check. You are saying genuinely that changing your breathing could have an effect on your stress that could genuinely have an impact on sort of your immune system. This is not just completely crazy woo-woo, like that's actually real? It does sound woo-woo. but when you think about the biomechanics of it, you know, when we inhale and exhale,

we're sort of making more and less space inside our chest cavity. So the heart is going to pick up on that and that's going to give the heart more or less space. So the brain is going to tell the blood flow to speed up or slow down. And this is tapping into the two arms of the what we call the autonomic nervous system. So that's your fight or flight response, which is kind of the stress arm. And then the rest and digest arm, which is the more kind of relaxing less stressed part of the nervous system so the counterbalance distress and elongating the exhale

so just taking a normal inhale and then making sure that exhale is slowed down through the nose this is going to really tap into that rest and digest parasympathetic part of the nervous system so it's helping to bring a bit of calm back to the whole nervous system and help take the edge off the stress

I'll end this recap with something I think you'll like a free gut health guide, created by our team of scientists here at Zoe. Many of us aren't sure how to best support our gut, so we developed an easy-to-follow guide, complete with tips, recipes and shopping lists, designed to help you look after your gut. The guide is delivered straight to your inbox, along with ongoing nutrition insights from Zoe,

the Science and Nutrition Company on a mission to transform their health of millions. To get your free gut health guide, just visit zoe.com slash gut guide. Thanks for listening.