ZOE Science & Nutrition - Most replayed moment: Reduce anxiety by improving your gut health | Uma Naidoo

Episode Date: March 24, 2026

Today we’re looking at a novel way to improve our mental health. If I’ve learnt anything from hosting this podcast, it’s just how interconnected all the systems in our body are. Nothing works in isolation, which means we often have to step back and look at the bigger picture if we want to improve a particular aspect of our health. With this in mind, let’s shift our focus on mental health. Can we approach it from a different angle? Harvard nutritional psychiatrist Dr. Uma Naidoo is here to explain the science behind the gut-brain axis, and how you can help one to help the other. 🌱 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 by our ZOE Scientists The Food For Life Cookbook Every Body Should Know This by Dr Federica Amati Food For Life by Prof. Tim Spector Ferment by Prof. Tim Spector Free resources from ZOE Live Healthier: Top 10 Tips From ZOE Science & Nutrition Gut Guide - For a Healthier Microbiome in Weeks  Better Breakfast Guide Have feedback or a topic you'd like us to cover? Let us know hereListen 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 looking at a novel way to improve our mental health. If I've learned anything from hosting this podcast, it's just how interconnected all the systems in our body are. Nothing works in isolation, which means we often have to step back and look at the bigger picture if we want to improve a particular aspect of our health. With this in mind, let's shift our focus on mental health. Can we approach it from a different angle? Harvard nutritional psychiatrist, Dr. Umar Naidu, is here to explain the science behind the gut-brain axis and how you can help one to help the other.

Nutritional psychiatry, and certainly when I practice, nutritional lifestyle and metabolic psychiatry is an evolving size. It's nascent and there's new evolving evidence every single day. But what we do know is that the trillions of microbes that live in our microbiome and our gut, as they're helping with the process of digesting our food, their breakdown products are also in the same environment as 90 to 95% of serotonin receptors. Now, serotonin is often called the happiness hormone.

There's serotonin the brain and other parts, but there's 90 to 95% of the receptors in serotonin production happens in the gut. So the linkage that I make that's been backed up by science is that as our food is being digested, it's also in the same environment as where these neurotransmitters are being produced, where the receptors are located. So we are therefore really understanding more and more that mental health is not this impact of just the brain. It's the brain in connection with the gut and other parts of the body. And can you explain a little bit more like what is a serotonin receptor? And if it's in my gut, how's that linked to my

brain and how does that then make me feel different? I think I was brought up, you know, sort of stiff upper lip, like whatever happens in the outside, it shouldn't really affect how you feel. I think that the science doesn't really seem to support this as much. What is going on? So I think the best way to think about it is in this way. The microbes, the microbiome, is associated and anatomically, physiologically and biochemically connected to the brain through the vagus nerve, through the anterioric nervous system, and through the transmission of these neurotransmitters. So serotonin exists in more than one place.

When I said serotonin is the happiness hormone, medications like selective serotonin re-uptake inhibitors or SSRIs are the medications that are used to treat conditions like depression and anxiety, but they also manipulate serotonin. So think about it this way. Serotonas is involved in conditions like depression, anxiety, and more. It's first-line medication in mental health that people are prescribed. But food is also involved.

And food is involved because it's being digested in the same place where the serotonin is being stored, manufactured, and the receptors are located. And it therefore can mediate emotion through how those interactions happen as food is being digested. For example, if you are mostly eating ultra-processed foods and sort of a poor diet, not only the breakdown products of that food are really going to lead to conditions like inflammation in your gut. And studies of inflammation in actually a big UK Biobank study of more than 144,000 participants showed that participants who had anxiety and depression also had increased markers,

and these markers were inflammatory markers, interleukin sick and Cereactive protein. So we know that inflammation is also involved. I want people to understand that there's this is gut brain connection, there's the mechanism for how food is being digested, seroton is right there, as well as other neurotransmitters in that environment. Another neurotransmitter, for example, is GABA. And GABA is associated with an inhibitory neurotransmitter. it's also associated with anxiety.

It's associated with the hippocampus. It's associated with the brain. Well, we found in a research study that a certain type of bacteria is associated with GABA production. And this type of bacteria's name is Bufidobacterium adalocentis. And when the production, for whatever reason, of that bacterium is low, GABA is low, and anxiety is high. So there's all of these different connections.

So I mentioned serotonum because of those receptors, but there are also these other neurotransmitters. And it's a more complex way to understand that anxiety is not just one thing, that the food you eat can impact these microbes and can thereby over time, not always immediate, can impact your anxiety. And, Uma, if someone's listening to this now, they say, like, I'm sold, I want to make changes. I am living with anxiety. or even if it's not clinically diagnosed, like I feel like I have a lot of anxiety in my life. What is the sort of specific advice you would give thinking about food to someone who wants to make changes that would maximize the benefit?

If I could just also add to what you said as I answer the question, that it may not be that you have a diagnosis, but you're feeling this way. And this is a very powerful tool that can help you. Food is one of the things that can help you, including things like breathwork exercise, exercise itself, and other things. Even sunlight are important. So I have three steps that I ask people to take, and I have the pneumonic SAW. So the one is swap. So swap one unhealthy food to get started.

So maybe you started eating ice cream every night during the pandemic. Can you create a recipe that I have, for example, for ice cream made from fruit and swap that out? Or can you start to eat less of it? So the first thing is swap. Swap, at least one unhealthy food habit that you have. it may be that you're not drinking enough water. It could be that. The second is add. So add in healthy, add in a healthy food. An easy way to start is adding in lots more vegetables,

colorful vegetables to your diet. Things like colorful peppers, lettuces, greens, spinach, whatever it is you might like. Adding those in a low calorie. So cruciferous vegetables like cauliflower and broccoli and Brussels sprouts, low calorie, and can be added in to, your meals that are both going to help you feel full, but they're also giving your body nutrients

and antioxidants and anti-inflammatory substances that your body and your brain need. And the third W is walk. And by walk, I mean movement, exercise, a Zumba class, a yoga class, whatever appeals to you to get you going. Because remember, through the lens of mental health, someone who's anxious may not even want to take a walk. So getting them to take a walk to buy the newspaper. get a cup of coffee, walk their dog is a way to get them moving and move from that almost

paralyzed state or feeling so anxious. I'd love to talk about people feeling anxious about their diet and how they can avoid that. And I think it's particularly relevant on this podcast. Most of the long-term listeners to this podcast will be Zoe members. They'll have been paying for this personalized nutrition program that helps them to feel better and be healthier. And one of the things that we've discovered is that we have to spend a lot of time and effort trying to sort of retrain people because they've been told that lots and lots of foods are off limits, that like these foods are bad and that sort of if they want to improve, it's all about sort of restriction, like calorie restriction, removing bad foods. And the way that Zoe membership works,

it's really all about focusing on adding things to their diet to be healthier. There's no calorie, recounting all of this. And also there's no, you know, one of the core ideas, which comes from a lot of nutritionists have been involved in it is that sort of no food is off limits. But what we find is that lots of people are still feeling really anxious about this. You know, even if they've been on the program for quite a while and they're feeling much better, I guess what's going on around that anxiety about diet? And do you have any advice to anybody listening about how they can reduce that? Well, I'll speak from the perspective of where I live in the US, which is, that we have a very eat-this, not that mentality, which I argue against as often as I can

so that people feel they can embrace all foods. Maybe it's the quality and quantity of the food, the source of the food, that becomes important. We talked about sugar earlier on, eating some berries or some, you know, a Clementine, a mandarin. These are healthy choices as part of not only a fruit serving, but the fiber and other nutrients have faith that you're on the right path to trying to make things better. It may not be perfect, but you are trying to work on consistency, which is one of the biggest things that will help you. Discipline around your food will help you.

The moment that someone starts to feel better, they want to do more of those healthy habits than that you can build on. If you're feeling anxious about the plan, maybe checking in with your nutrition counselor about it, what's driving that anxiety? Is it the quantity of food? Are you maybe not drinking enough water? Are you maybe eating something?

Here's a common mistake that people make. I shouldn't say it's a mistake. It's more that they don't realize, for example, yogurt, rich in probiotics, great food, blueberries, delicious fruit, great source of fiber and anthocyanins, good for your diet. Fruited yogurt, so the fruit in the yogurt, not a good idea. Because in the United States, a small half-cup serving can have. six to eight teaspoons of added sugar. So often someone might be eating something. They think and have heard and red is healthy, but the food industry is not necessarily our friend and is labeling food

in a way that you think it's healthy, but it's not because of those added sugars. A simple swap would be plain yogurt with berries and a sprinkle of cinnamon. It's super delicious. You get all the benefits from every ingredient, including the cinnamon. So those types of things may be worth discussing with your counselor or whoever you speak to to check in about what's driving that anxiety. Or maybe it's that you have too much or too little food in your plan. It could be many different things. You know, I always take it back to when we were first, when we were first born, what happens when a baby is born? So if you've ever seen on television or you work in the or the labor and delivery, you know that you want the baby to cry. They take a deep breath. And

what happens next? Yeah, they clean them up and all of that, but they feed. So think about food is something very primitive. It's very primary to who we are as humans. And I think that when sometimes we're in situations where can't eat this or there's a media report that you shouldn't eat that, it really drives anxiety. Like food anxiety is a very big thing. And I feel like, understand you're on a healthy path. Remember, saw, swap, add, walk. Think about calming foods because I have an acronym calming and I also add in foods based on that. So very quickly, C is for coline. Colleen is and eggs and legumes. A is for something like antioxidants. L is for liquids. Calming teas like passion flour or chamomile, liquid water, very important. And M is more omegas and magnesium.

So many more foods on every letter of the list. But just very quickly, think about foods you can start to add in that help that anxiety. So if you're on the plan and you're worried about the plan, ask yourself why. Maybe it's something related to questions you have that are not answered or information you need. But you can also add in foods that could help you even more. 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 the health of millions. To get your free gut health guide, just visit zoe.com slash gut guide. Thanks for listening. You know, I'm sorry. Thank you.