8 foods that soothe anxiety

1 in 3 people have anxiety. It’s the most common mental health disorder in the world. And many of us know what anxiety feels like: palms sweating before a job interview, losing your appetite before a looming deadline, a pit in your stomach when you get bad news. It’s not just in your head, it’s in your gut.

Dr. Uma Naidoo is on the forefront of nutritional psychiatry. She directs the first hospital-based Nutritional Psychiatry Service in the US, at Massachusetts General Hospital and teaches at Harvard Medical School.

Uma will help you understand the symptoms and biology of anxiety, painting a picture of the risks it poses for long-term health. And her diet tips will help you fuel your gut for a healthy mind.

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Transcript

Jonathan Wolf: One in three people have anxiety. It's the most common mental health disorder in the world. And haven't we all felt anxious before? Palms sweating before a job interview. Losing your appetite before a looming deadline. A pit in your stomach when you get bad news. 

Anyone who's felt anxious knows it's not just in your head, it's also in your gut. Trillions of gut bacteria send messages to your brain and these messages influence your mental health and vice versa. And this means that just a few hours of stress can change the composition of your gut bacteria. So if your mind is in a constant conversation with your gut, then the food you eat should be bringing you good news.

So how do you eat to calm your mind? Well, today's guest wrote two books to show you how. Dr. Uma Naidoo is a nutritional psychiatrist at Harvard Medical School, who runs the world's first nutritional psychiatry department at Massachusetts General Hospital. Her book, Calm Your Mind With Food is a revolutionary full body approach to relieving anxiety. Oh, and to top it all off, Uma's also a professional chef. 

You'll walk away from today's episode knowing how to gain better control over your anxiety using the power of the foods you eat every day. 

Uma, thank you for joining me today. 

Dr. Uma Naidoo: Thanks so much for having me. I'm excited to be here. 

Jonathan Wolf: Me too. This is a new topic for us and I'm really excited to have you.

Now we have a tradition here at ZOE where we always start with a quick-fire round of questions from our listeners. It's designed to be very hard for academics because we have these very strict rules. So you can say yes or no, or if you have to, you can give us a one sentence answer. Are you willing to give it a go?

Dr. Uma Naidoo: Yep. 

Jonathan Wolf: Alright. A decade ago, did people think there was a link between nutrition and mental health? 

Dr. Uma Naidoo: No. 

Jonathan Wolf: Is there new scientific evidence to suggest that diet can change your mood? 

Dr. Uma Naidoo: Yes. 

Jonathan Wolf: Does your brain communicate with your gut bacteria? 

Dr. Uma Naidoo: Yes. 

Jonathan Wolf: Can a stressful day at work change the composition of your gut microbiome?

Dr. Uma Naidoo: Yes. 

Jonathan Wolf: Are there foods that might alleviate the symptoms of anxiety? 

Dr. Uma Naidoo: Yes. 

Jonathan Wolf: So now you get a whole sentence for this one. What is the biggest misconception about anxiety disorders? 

Dr. Uma Naidoo: If you change your diet in a good way, you can help lower your anxiety within one to three weeks. It's real and I've seen it. 

Jonathan Wolf: So we've all felt anxious at some point, whether, you know, it's a disorder or not. And I was thinking about when I feel anxious, I feel it like in all parts of my body. So I'm thinking sweaty palms, my heart's racing, shortness of breath, and I think most of us also feel anxiety in our gut. So loss of appetite, nausea, a sprint to the bathroom. 

But I'm really struck that you said that just 10 years ago, people didn't see much of a link between our gut health and our mental health. Can we start at the beginning? What is anxiety? 

Dr. Uma Naidoo: Many different things, but there's specific criteria by which a mental health clinician can diagnose you. But in clinical practice, often there might be more symptoms. 

For example, anxiety often hides in things like insomnia. And often when I'm working with someone, and we work to improve their dietary measures, and through a nutritional psychiatry plan, that includes looking at lifestyle and metabolism, the sleep improves, but most importantly, they realized that the sleep was actually being disrupted by anxiety. 

So it often hides in other conditions that we may report as a symptom. I think that's important to understand. 

And it's also important to understand that anxiety occurs along a spectrum. You might have mild anxiety that is somewhat appropriate before writing an exam, taking a test, some big event. But you might also have disabling crippling anxiety where you can't leave your home or get to work or even get out of bed to a zoom call because you are so warped by what ever you're feeling that keeps you frozen in place or unable to function. And that is a more serious severe form.

It's important for people to understand that there's this almost linear or longitudinal way in which people can present. 

Jonathan Wolf: Could you help me to understand a bit more of the difference between feeling anxious, which I think happens to all of us, and being diagnosed with anxiety?

Dr. Uma Naidoo: So, if you're anxious before an exam, then you write your exam, and you're pretty happy after that, and you're hanging out with your friends, and you're doing okay, you're sort of returning to a normal baseline. 

Whereas if you are really struggling with anxiety, all moments of your day may be anxious and there may be times when you actually can feel okay, but it's a short period of time and you start to feel anxious again.

Often it's unprecipitated anxiety, meaning you walking to get a cup of coffee or going to the gym or whatever it might be and you start to feel your heart racing or you have the onset of a panic attack. And very often, patients will tell me or clients will tell me it came out of nowhere.

So it also has that feeling to it, and it tends to, over time, cause you to be able to function less at your peak. So, you might be able to function, go to work, conduct what you need to do, but you may not be working or living optimally. 

Jonathan Wolf: Got it. And this is then diagnosedby a clinician and that's how you distinguish it.

So, it seems like we should be less anxious than in the past, now that most of us don't have to worry about, I'm definitely not going to wander and see a lion in front of me, I'm very unlikely to have to worry about starving to death. It feels like there were all those things in the past that you'd have a good reason to feel anxious every day, all the time.

Is there less anxiety now than there was a few hundred years ago? 

Dr. Uma Naidoo: So I think we have to compare it in the more recent times and I'll tell you why. Anxiety has actually always been the most common condition in the world, specifically in the United States. But depression is more disabling for people and that is why people talk about that more often.

Often depression and anxiety run together. But despite all of that, anxiety increased by 25% after the pandemic worldwide. 

Jonathan Wolf: Uma I just want to confirm, you said it's gone up 25% since COVID just a few years ago. 

Dr. Uma Naidoo: Yes, 25% and this was published in The Lancet. And so if you have a friend, family member, colleague, spouse, friend, whoever it might be that's feeling anxious, or you're just noticing it when you go to buy your cup of coffee, it's real.

And I feel like that really is what I've been seeing in my practice over the last several years. A real spike in individuals who didn't have anxiety before, who are wondering where this is coming from, developing it at a later stage in life sometimes. 

I think it's therefore pretty serious and one of the epidemics in the world that is not being addressed. While mental health isn’t crisis, some of it is driven by that level of angst and anxiety that everyone is living with. 

Jonathan Wolf: I feel we often talk about being stressed a lot and I definitely feel that I have a lot of stress at work. Is there a difference between like, I feel quite stressed or I've got a stressful job that I'm thinking about and anxiety?

Dr. Uma Naidoo: Yeah, I think of anxiety as more clinical. Meaning that the symptoms we talked about and then those diagnostic criteria, whereas stress is sometimes used more widely to describe more of a state of mind. Stress related to my job, travel, commuting, something like that. Whereas anxiety may be much more intrinsic to how you're feeling and carrying that.

But stress and anxiety are also linked. For example, people talk about stress eating all the time. And those things are linked. 

Jonathan Wolf: Can you tell me what's going on in the brain with somebody who's living with this anxiety. 

Dr. Uma Naidoo: So the flashpoint of anxiety in the brain is a region called the amygdala. Now we know from the study of the microbiome and study of the gut and the brain that the gut and brain are connected.

It starts with the fact that the gut and brain originate from the exact same cells in the embryonic cell line and then develop into two separate organs that are different parts of the body, but they remain connected by the 10th cranial nerve, the vagus nerve. And the vagus nerve is really a two-way transmitter for text messages.

These text messages are actually in the form of neurotransmitters between the brain and gut, and the gut and brain, it's bidirectional. So the flashpoint for anxiety is this region in the brain. 

It might be that you had a very stressful day at work and you were anxious or you had an uncomfortable or worrying situation with your boss and your gut microbes are starting to evolve and change in response to that stress.

It might be that that caused you, because of what was going on at work in the last week or longer, to be ordering junk food at work instead of ordering a healthy salad, getting takeout and eating that consistently. 

Maybe you went out with your friends and instead of usually having a glass of wine once a week at dinner, you're having one to two glasses of wine, maybe, maybe a beer every night because of the situation that's happening. 

So, you find over time this buildup of anxiety. And that is, of course, unrelated to everything else that might be going on in your body. But I'm looking at it from the angle of food, nutrition, and how this might be impactin your behavior.

Jonathan Wolf: So I love this idea. You're saying that my gut and my brain, when I was a tiny embryo, were like the same thing. 

Dr. Uma Naidoo: Same exact cells. 

Jonathan Wolf: They separated out, but they sort of stayed in touch. I think that's brilliant. I've never heard that before. 

Dr. Uma Naidoo: They have stayed in touch, exactly. 

Jonathan Wolf: And I think you've also made clear that the amount of anxiety, people living with anxiety has been growing a lot.

I'd love to turn now to how nutrition is fitting into that, because I think a lot of people listening to this episode will be quite surprised that then you're saying that the food you eat would affect this. Because I think many of them like me will naturally have gone to, it's sort of the stress of modern life in the sense of the job and the phone and whatever else.

Dr. Uma Naidoo: It could be aspects of that too. But it's also food. And that's the part that often gets ignored. 

Jonathan Wolf: So why does nutrition impact our mental health? 

Dr. Uma Naidoo: It goes back to one of the mechanisms being that gut brain connection. The fact that neurotransmitters are communicating and the fact that the food we eat is being digested and interacting with the microbes in our gut.

Jonathan Wolf: And Uma, can you help me to understand a bit more about how these gut bacteria can be having any effect on the brain, because I know you've mentioned one or two that there's some link, but what's actually going on? They feel like they're a long way away from each other, gut bacteria are really small, like what's going on and how real is this science?

Is this your own, very high-profile science-driven view or is there real science behind what you're describing? 

Dr. Uma Naidoo: Yeah, so there's real science behind it and it's been researched, it's been studied, and it is evolving science. 

Nutritional psychiatry and certainly when I practice nutritional lifestyle and metabolic psychiatry is an evolving science. 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, in our gut, as they're helping with the process of digesting our food, their breakdown products are also in the same environment as 90-95% of serotonin receptors.

Now serotonin is often called the happiness hormone. There's serotonin in the brain and other parts, but there's 90-95% 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. 

Jonathan Wolf: 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 was brought up, you know, sort of stiff upper lip, like whatever happens in the outside shouldn't really affect how you feel. I think that the science doesn't really seem to support this as much now, what is going on? 

Dr. Uma Naidoo: So I think the best way to think about it is, is in this way. The microbes, the microbiome is associated anatomically, physiologically, and biochemically connected to the brain through the vagus nerve, through the enteric 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 reuptake 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. Serotonin 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.

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 in actually a big U.K. 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 6 and C-reactive protein. 

So we know that inflammation is also involved. I want people to understand that there's this gut-brain connection, there's the mechanism for how food is being digested, serotonin is right there as well as other neurotransmitters in that environment.

Another neurotransmitter, for example, is GABA. And GABA is associated. It's 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 Bifidobacterium adolescentis. 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 serotonin 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. 

Jonathan Wolf: Let me play back what I think I'm understanding because this is definitely quite complicated. The bacteria in our gut are creating these chemicals and they're then interacting with our own cells that are in our gut wall, which are available. 

You mentioned the thing like serotonin, but some other neurotransmitters. And then somehow this is sending a signal up to my brain that is then changing what's going on in my brain. Is that right? How does that work? 

Dr. Uma Naidoo: So the neurotransmitters are transmitted via the vagus nerve, which is the 10th cranial nerve, which is going directly to your brain. 

Jonathan Wolf: So there's a nerve from my brain to my gut. Like there are nerves to my fingers that I'm flexing right now. 

Dr. Uma Naidoo: Exactly. And it turns out that the vagus nerve, another name for it is the wandering nerve, it goes to so many places in the body. But it is actually a direct anatomical connection between the brain and the gut itself.

Jonathan Wolf: It gets to my brain. Why does this change how I feel? How's that making me anxious? What's going on in my brain? Can you see a difference between someone who's living with anxiety versus someone who's not? Is that something you can actually see in the brain?

Dr. Uma Naidoo: I'm not sure that we can see it in the brain, but we have the serotonin hypothesis that has lasted for many years. A couple of years ago, a very important study published in a British journal actually upended that hypothesis and kind of questioned it, which I think was very interesting. Showing us again that we're not 100% certain in mental health of some of these pathways, but we work with what we know.

In other words, mental health is never a tissue diagnosis and what do I mean by that? If you have a cough and a chest infection or pneumonia, your doc will probably ask you to cough up into a cup, draw some blood tests and make a diagnosis. In mental health, we don't have that. We don't have a brain biopsy that will diagnose something.

We have always used these diagnostic criteria that are based on a lot of information that we've put together for these manuals. So I don't want to imply that it's soft science because it's not. Mental health is very real and conditions need treatment and the medications that have been designed do help that.

But I'm using it as a lens to explain that a medication like an SSRI, like Zoloft or Prozac, Sertraline. or Fluoxetine are the other names, will actually impact those serotonin receptors and change the levels of serotonin in your brain to actually make you feel better. 

On a separate note, those medications don't always work, so we clearly need more solutions to help people.

Jonathan Wolf: I've got it. So I think what you're saying is, firstly, there isn't just a blood test or something like this where you can figure out a level of anxiety. That doesn't mean that it's not a real diagnosis, but scientists haven't developed a way to measure this in just a single test. 

And that this role that you've been describing is that bacteria are then really interacting with these receptors in our gut and then they're sending these signals on these nerves to the brain and this is shaping us. 

The very targets that you're describing for the drugs that we've heard of like Prozac is definitely one I suspect most listeners like me have heard of before. It's like the same thing that these bacteria are influencing. 

Dr. Uma Naidoo: The bacteria influencing all of this as well. And the bacteria are impacted. One of the things that impacts, and we mentioned stress earlier, but they're also impacted by the food that we eat and that's where food can become something that we can alter to improve how we're feeling emotionally.

Jonathan Wolf: And I want to come on to that, but just before I do that, I just wonder, is there also something that goes the other way around, which I think you talked about in your book, that I thought was really interesting. So, can stress affect the bacteria in your gut? 

Dr. Uma Naidoo: Yes. So, you may not notice it immediately, but research has shown that, say you have that stressful day at work, an argument with your spouse or partner, the gut bacteria actually respond to stress within a very short time and start to evolve and change, not in a good way, because stress does not impact them in a good way. 

When we're stressed, our cortisol levels go up, it impacts many of our different hormonal systems in the body, and it actually can lead to heightened anxiety. So, understanding that the gut microbes are responding all of the time, and we want them to really work for us, not against us.

Jonathan Wolf: And Uma, how fast will my gut bacteria change if I've had that sort of row with my wife this morning? 

Dr. Uma Naidoo: So some of the research has shown within two hours, they start to evolve and change. Now, does that mean they produce anxiety? No, not in the immediate two hours. But over time, if a stressful situation persists, they do start to evolve and change further. But they start to react almost immediately. 

Jonathan Wolf: And is this one of the ways that being under stress for a long time can make you anxious? That it could actually change? 

Dr. Uma Naidoo: It is definitely one of the ways. 

Jonathan Wolf: Can I ask a different question, since I've got a world expert here, which I'm really interested in? I think lots of people, and I feel the same way, say when I'm feeling really stressed and anxious, I crave unhealthy food in a way that when I'm feeling calmer, I don't.

Is that a real thing? And what's going on? 

Dr. Uma Naidoo: It is a real thing. I'm always going to say there are more than one mechanism because there are, and I also want to make sure we understand science is evolving. I'm never 100% certain about one thing at one time. But we follow what that says and that helps us treat people clinically.

But stress actually precipitates habit circuits in the brain meaning that when you're stressed you might choose unhealthy foods and you might enjoy that food, and the next day you decide, let me order that again, and it's still an unhealthy food, right?

But that stress actually precipitates those habit pathways or circles in the brain. So when someone says to me, I'm stressed, and I'm eating poorly, or I have stress eating, they may be using a term that we, sort of an everyday term, but it actually has some science behind it. 

When that happens, you just continue along a path that you continue eating those unhealthy foods, and it's very hard for people to break that cycle.

There's a real reason that your brain is acting that way, and some foods, like highly sugared foods, things like high fructose corn syrup, actual sugar, so I'm not talking necessarily about healthy versions of sugar because you always want to have a couple of servings of fruit, talking about really eating candy and cookies and cake all the time, research has shown that sugar impacts dopamine reward pathways in the brain.

In a similar way to street drugs like cocaine. So, when people talk about sugar addiction, it may be a strong term, but they're actually describing how they're feeling, and they cannot step away from sugar. So, that's real too. 

Jonathan Wolf: I mean, I have to follow up on that for a minute, when you're saying you can be drinking a sugary drink and it could have a similar impact to cocaine. Could you explain a bit more what's going on there? 

Dr. Uma Naidoo:  So cocaine is a street drug that will tap into the dopamine reward pathway, another neurotransmitter in the brain. And it kicks into certain behaviors and it makes you feel a certain way. And it also makes you feel, because of the reward system, makes you feel good. o you want more of it. 

Sugar does a similar thing. It makes you feel good in the short term. The long-term impacts of sugar on neurons in the brain or the brain cells is not good. But in the short term, people feel great. They have that little feeling of after they eat sugar, but then they can't step away from it. They want more and more. 

When people say they're addicted to sugar, it is a strong term, but it is a real feeling that people feel where, you know, I cannot not have my bag of candy or my two chocolate bars after lunch or something like that. 

Jonathan Wolf: And when you say addicted is a strong term, but they do want it, could you just help me to unpack that a bit more?

Dr. Uma Naidoo: Sure, all I mean is sometimes scientists say, well, oh, you know, addiction is such a strong term for sugar. Because maybe it's just that someone is eating too much sugar. But I see individuals who literally cannot live without it. 

Now understand that we need sugar in our bodies. It's part of a normal healthy diet, but it's where we obtain our sugar from that's critical. You know, we don't want our sugar from high fructose corn syrup and added sugars. The 262 other names for sugars that I found on us food labels are not the sugars that we want because they're hidden sugars.

And when we consume them, we get used to them, and they taste good. In the short term, they make people feel good, so they continue to want to do that behavior. 

Jonathan Wolf: So there is a real thing, which is like, I'm feeling down or anxious, I'm not even talking about somebody who meets your definitions of like a clinical condition, that actually, eating a sugary doughnut or a Coca-Cola with sugar or whatever, that's literally going to trigger something in my brain that's going to give me like a little temporary blip of positivity. That is real?

Dr. Uma Naidoo: Yes

Jonathan Wolf: And then what I think you're saying is that creates this feedback loop. I get a crash shortly afterwards and then I'm like, oh, well, I want to have this again. 

Dr. Uma Naidoo: People don’t forget the crash and they also don't realize what's happening to the insulin and the blood sugar, but they do feel that emotional crash and then like, well, have you ever wondered why they sell two doughnuts at a time?

Well, my theory is that you have the first donut and you experienced that, then you need that second doughnut and you're not satiated. It's not food that's filling and fiber-filled and nutritious. It's just laden with sugar.

Jonathan Wolf: Really interesting, but you're saying that actually there is this real thing when if you're anxious, whether you're under stress, it sort of pulls you into this.

But then your analogy with cocaine is obviously strong, but we all know that if you are feeling stressed, that cocaine is not a good solution to this problem. I don't think anyone listening to this, even anyone who might be using it thinks it's a good solution to to this.

Dr. Uma Naidoo: So just to be clear, the connection between sugar and cocaine is this particular research looked at the fact that cocaine tapped into this dopamine reward pathway or reward loop in the same way that sugar does. 

Jonathan Wolf: What is a dopamine reward loop? 

Dr. Uma Naidoo: So dopamine is a neurotransmitter, and when people use cocaine, makes them feel good, and they want more. Very simply, this research looked at sugar and sugar does the same thing. Makes you feel good like that donut and then you want more.

So I take it very seriously when people say, you know I really just can't give up sugar and I think it's really not about giving it up completely. It's about finding healthy sources and healthy amounts of sugar I've figured that you eat.

Jonathan Wolf: That's fascinating and I think we just started about like does stress and anxiety make us crave unhealthy food and it sounds like it's in a sense, this stuff that's out there does have this amazing short-term impact on us.

I guess the stress and anxiety makes it harder to resist and also that little buzz that you get feels particularly rewarding when you're feeling a bit down.

Dr. Uma Naidoo: Yes, it does feel rewarding. It's short-lived, then you might reach out for more or you might not feel good and feel a little bit down, feel more anxious. And it really does create almost a very uncomfortable loop. 

Jonathan Wolf: So I can definitely see this pathway where you can get pulled into the ultra-processed food that we're surrounded by.

Just before we switch to I think a really positive thing about what are all the things you can do, I just wanted to ask, are there health risks associated with living with sort of chronic stress and anxiety? 

So obviously what you're describing is very uncomfortable for how you're feeling. Does it also affect your body and your health? 

Jonathan Wolf: Yes. One of the things that we haven't really touched on is the fact that this is a very integrated and holistic approach to helping people, right? 

We need to understand that, like I said a few times, the brain and the rest of the body are all connected. Without the brain functioning, the rest of the body cannot work. So it is, in fact, the most important organ in the body. 

When we are so stressed and anxious, things that are happening in our body, include a heightened cortisol level, heightened level of stress people may have an impact on metabolism.

Because they are stressed, they may be eating poorly. That may lead to things like leptin resistance over time, which impacts their metabolism. So leptin is the hormone that tells us that we're full and eat a plate of food, put it down, put your knife and fork down, you drink a glass of water and you're done.

When you develop leptin resistance, one of the reasons can be extreme stress, you don't feel satiated, you want a second plate of food, you want cookies after dinner. 

Jonathan Wolf: So Uma, I just want to make sure I've got this. You were saying if you're having long-term stress or anxiety, this is something you can measure in your body that means you're not able to feel full in the same way and therefore you're actually going to eat more because it's actually changed the biology of what's going on inside you.

Dr. Uma Naidoo: That is true. So where anxiety and metabolism are associated and where metabolism in our body which is also associated with mental health. It's a connection that we're really understanding better now. And the link I'm trying to make is that when we have this chronic persistent stress, it, one of the ways that it impacts through the lens of nutrition is how we eat.

Because if we start to eat poorly, over time, it can affect what we call our hunger hormones. And they stop functioning properly. They stop telling us that we’re full. That we should stop eating. and have a glass of water and maybe watch a television show or take a walk after dinner. 

It does the opposite. It's, well, I need another plate of food and then I want a dessert. And after the dessert, I want a snack. And this is when people start to develop leptin resistance. So it's one of the consequences of stress through the lens of food. 

Jonathan Wolf: And this is real science, we've really been able to see this change in the leptin resistance that you're talking about?

Dr. Uma Naidoo: Yes, so leptin resistance can develop, your metabolism is impacted, cortisol levels are affected, you may start to gain weight, you may not be able to sleep well, you start to experience more anxiety, all of that. 

Jonathan Wolf: I'd love to switch to like what are the actionable tips? Yeah. That can help our listeners to gain more control over their mental health. And since this is ZOE Science & Nutrition, I'm bound to start by asking about food. 

How can we use food to calm our mind? 

Dr. Uma Naidoo:  So I would like to answer that question by saying that food is one of the pillars of helping conditions, like anxiety, mood disorders, and more. 

But it is also, in conjunction with practices like yoga, meditation, Shirin-yoku or forest bathing, in other words, being close to nature. Maybe it's learning a breath-work exercise. Maybe, you like to do tai chi, some type of movement, many, many different things. 

Also things like hydration. Keeping adequately hydrated is critical for really not feeling anxious because dehydration can lead to anxiety.

We've talked about the mechanisms and some of the mechanisms, but the way that food can calm the mind is through the selections that we make. When we are eating fiber-rich, plant-rich diets with healthy fats and healthy proteins from clean sources, we are feeding our body with nutrient dense foods that are antioxidant-rich, rich in anti-inflammatory substances.

You've heard the expression, the color of the rainbow. I like to call it a kaleidoscope of color because it's so many brilliant and beautiful colors and it represents so many different antioxidants and polyphenols from plants that represent positive substances we are feeding those gut microbes with.

Jonathan Wolf: And Uma, can you help us understand what happens as you change this food, what's going on with these bacteria, and then how does that flow through in a positive way?

Because I think you've talked a lot about the bad things that could happen. 

Dr. Uma Naidoo: Within these trillions of microbes that live in the gut microbiome, there are the good guys and the bad guys.

When we are feeding bad guys, that leads to inflammation. We talked about gut damage, gut lining damage, hyperpermeability, or intestinal permeability, that type of stuff, or leaky gut. 

But when we're feeding the good guys, they are thriving, they are being fed, they are helping us, their breakdown products called short-chain fatty acids, which take care of the gut, help healing of the gut, and the moment we start to switch to healthier foods, people will start to notice changes.

Sometimes they just notice their sleep starts to improve, sleep is related to anxiety. Or they notice that they don't get up with that horrible pit in their stomach, feeling so anxious about getting to go to work that day. 

Jonathan Wolf: And how fast in your practice when you see people, you know, do you start to see this improvement? Are you seeing that people are waiting, is it years after they start to make these dietary changes that they start to see an impact?

Dr. Uma Naidoo: Fortunately, it's sooner than that. I have individuals call me within a week to say their sleep is starting to improve. They're not cured. That would be the wrong term, but they're starting to feel better.

And they feel much more positive and they want to do more of these nutritional things, kind of therapies and a nutritional treatment plan. But sometimes it's up to like one to three weeks where they really start to notice that they're less anxious, they're waking up better, they're sleeping better. When they're eating healthier, they’re satiated or they've eaten a plate of food and they're full. 

Whereas if they had gotten takeout or other foods, they want more than one bag of fries or whatever it might be that was sort of driving that. And so they start to feel better. 

Jonathan Wolf: I was thinking Uma if you told me that even two years ago, I think I would have been completely shocked. And what's changed between now and then is we have something called ZOE membership, which is our personalized nutrition program, and we ran a full randomized controlled trial of that that was published in Nature Medicine a few months ago.

So we looked at the outcome of people going through ZOE membership compared to people following the standard advice in the States. We got them to report not just on sort of blood work and waist circumference and things like that, but also on energy, and hunger, and mood. 

And what was totally amazing is we saw these really big improvements in people reporting things about sleep and about mood. And I never would have expected it because it when the scientists were originally designing this program, it was very much focused on long-term health and improving the microbiome.

It wasn't at all thinking about mood or sleep, but there's these really big statistical changes, which I was shocked by. And so now hearing you talk about this, it sounds as though in a way you're not surprised about that.

Dr. Uma Naidoo: I'm not because I've seen in clinical practice for a while, and I'm grateful that more studies are proving it, like the studies that you all performed.

And I also think that science is exciting and evolving, especially around the areas that you all work on at ZOE. Because there's this research lab at Harvard associated with Beth Israel Deaconess Medical Center that published a study, earlier in September of 2024, where they are looking at a gut first approach for conditions like Parkinson's.

So they did a cohort study on, I think it was just over 9,000 patients, and found that those that had mucosal, that's the lining of the upper GI tract, that was damaged or problematic and that can be caused by taking medications like NSAIDs. Examples are ibuprofen or could be GERD, gastroesophageal reflux disease. It could be ulcers from things like H. pylori that can cause damage. 

There was 76% more prone to developing a clinical diagnosis of Parkinson's. So by looking at a gut-first approach, all I'm speaking to is the power of the microbiome. 

They're wondering about where does Parkinson's really originate. We'd always thought it was more of a brain-based disease, but when we look at patients who develop Parkinson's disease, early on, they have gut symptoms. They might have nausea, they might have constipation and discomfort in their gut. 

It often happens many, many years, even more than a decade before the actual diagnosis that has more of a neurological, psychological feel to it.

So, it's fascinating work. 

Jonathan Wolf: That's amazing. So you're saying, this is obviously very early science, it's really exciting that you're sharing it, that they're actually saying that there might actually be a link, it's issues that are starting in your gut, turning into Parkinson's, you know, maybe 10 years later, and I guess another example of the link you're describing between the gut and the brain.

Dr. Uma Naidoo: Correct. Exactly. I think we have to follow the science and we also have to be humble about it because it does change and evolve all the time. 

I think the research done in the U.K., that to some extent, upended some of the serotonin hypothesis of conditions like depression, was very compelling. But that doesn't mean you should stop taking Prozac. It means you should have a discussion with your doctor. 

Jonathan Wolf: And it sounds like there's, in fact, from the way you described that, there's a lot we don't understand about how mental health works. 

Dr. Uma Naidoo: There's a lot we don't understand. And to me, that was something that really pushed me in the direction of nutrition.

Not only did I feel compelled to find more solutions for my patients, I felt that it was a stone we were leaving unturned. We were prescribing all these heavy-hitting medications that, in fact, had side effects like weight gain or other problems, but we were not really addressing real lifestyle and diet.

So, other than a checkbox collecting someone's weight and height, we were not really asking about what they were doing that could help them with food.

Jonathan Wolf: And Uma, if someone's listening to this now, they're saying 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?

Dr. Uma Naidoo: If I could just also add to what you said as I answer the question. 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 mnemonic SAW, S-A-W. 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 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 are low calorie. So cruciferous vegetables like cauliflower and broccoli and Brussels sprouts are 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 of feeling so anxious.

Jonathan Wolf: We have a lot of podcasts that talk about exercise and people have been sharing amazing impact. Scientists can talk about amazing impact on health, but does exercise have any impact on your mental health? 

Jonathan Wolf: It does. There's a whole body of research on exercise and mental health, improving mood, depression for one simple thing. If you've ever had the experience of running on the treadmill and maybe you were really pushing yourself. You didn't feel motivated that day and you spent half an hour on the treadmill and you feel really good after that. You're calling your friends to say what a great day it is. That's often because of the release of endorphins in your body.

So beyond that, there's a lot more evidence to show that exercise helps mental health, improves depression, lowers anxiety. Some of my clients will say they get on a treadmill for 20 minutes that they feel anxious or do some form of exercise because it almost inhibits the anxiety and it kind of catches it because it distracts them and it gives them something else to do when they're so warped or wrapped up in that anxious moment.

Jonathan Wolf: I try and work out three times a week because I've been sold about the benefit of my health, but I often tell my trainer, I definitely get no endorphins during the session, but I feel like I get a lot at the end after I feel really good that I’ve done it.

Dr. Uma Naidoo: That's exactly right. At the end of the hour or whatever amount of time, you know, you feel sort of good and part of it is the accomplishment of doing it, but also it's the way your body is responding.

Jonathan Wolf: There really is something real. It's not just about long-term health. I can actually affect my mood with it as well. 

Dr. Uma Naidoo: It can affect your mood. So that's why I had, you know, the W in for whatever movement it might be that you're doing that helps you. 

Jonathan Wolf: 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. 

One of the things that we've discovered is that we have to spend a lot of time and effort trying to retrain people because they've been told that lots and lots of foods are off-limits. These foods are and if they want to improve, it's all about restriction, 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 count, all of this.

And also, one of the core ideas, which comes from a lot of nutritionists that 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? 

Dr. Uma Naidoo:  Well, I'll speak from the perspective of where I live in the U.S., 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 a Clementine, a Mandarin. These are healthy choices as part of not only your food 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 and 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. It's a 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 they think and have heard and read it's 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. 

I always take it back to when we were first born, what happens when a baby is born. So if you've ever seen on television or you work in an ER or the labor and delivery, You know that you want the baby to cry, they take a deep breath, and what happens next? They clean them up and all of that, but they feed. 

So think about food as something very primitive. It's very primary to who we are as humans. And I think that when sometimes we're in situations where you can't eat this, or there's a media report that you shouldn't eat that, it really drives anxiety.

Food anxiety is a very big thing. And I feel like understand you're on a healthy path. Remember, SAW; Swap, Add, Walking. 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 choline, choline is an eggs and legumes. A is for antioxidants. L is for liquids; calming teas like passion flower 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.

Jonathan Wolf: Uma, I want to just go through that again, just a little bit more slowly, because it sounded great. So you're saying for people who are having this anxiety, which might be also anxiety about their list, you had this acronym CALM.

Dr. Uma Naidoo: Could you just talk me through it? 

It's actually CALMING, but I'm going to share CALM with you, in the interest of time. C is choline. Choline is a substance, an important nutrient found in eggs, but it's also found in legumes. I also think of C, two other Cs, extra dark natural chocolate, a great source of magnesium, fiber, and serotonin, believe it or not. So extra dark, we're not talking about candy bars, we're talking about extra dark natural chocolate. And another C is vitamin C. 

A fun fact is that natural chocolate in that way is the highest source of plant-based iron. You usually get iron in meats. 

Jonathan Wolf: But I can get iron in my dark chocolate? As anyone who's a regular listener to this will know, I'm completely addicted to dark chocolate. So I love that you're giving me, I think, iron. And did you say I get serotonin from it as well? 

So now I know why I'm addicted to it. So this really is my cocaine, is there? 

Dr. Uma Naidoo: Sometimes it takes a while for people to get used to that extra dark version, but it's worth it. 

But here's the kicker, if you have the extra dark chocolate with a piece of citrus fruit, like a mandarin or clementine, it helps the absorption, the vitamin C helps the absorption of that iron. So always pair that together. 

And by the way, I happened to learn that in culinary school and I think they were really teaching it to us because of flavor, the flavor profile of dark chocolate with citrus, but it actually has some science behind it, which I thought was interesting.

Jonathan Wolf: That's amazing. So if you pair, and I know we haven't managed to get into the fact that you were trained as a chef, but you're saying if I pair the dark chocolate with like some sort of citrus fruit, it not only tastes good, you're saying, but actually somehow it unlocks the iron better for my body. So we were on C of calm.

Tell me about the other three. 

Dr. Uma Naidoo: A is both ashwagandha, one of my favorite supplements for anxiety. It's very bitter-tasting, so it's worth looking into a clean supplement or antioxidants. Think colorful vegetables that we've talked about, colors of the rainbow, all of those really bring you the antioxidants we need, but so do spices, spices and herbs.

L is for liquid. So I want people to remember, the reason I put liquid in is water, just plain water is an important part of that. Hydration is really helpful for anxiety or keeping well hydrated, I should say. And other things like a calming tea that you like could be good too. 

Anooma, is that true?

Jonathan Wolf: And Uma, can a tea actually affect your anxiety? 

Dr. Uma Naidoo: Yes, it can. Passionflower tea, green tea, all of these have actually have some science behind them. So just having or sipping on that calming tea not only helps you, but it's hydrating and it's calming. 

And M is for a lot of Americans are low in magnesium. And so I want to remind people to maybe talk to their doctors about getting the magnesium level checked if they're suffering with anxiety. And also the other M is more omega-3 because these are important to get from things like salmon or plant based sources from hemp seeds and flax seeds.

Jonathan Wolf: Brilliant. Uma, I have so many more questions. We're sort of out of time, so I want to finish with one last one. 

So you've already just mentioned that you're also a professional chef on top of everything else, which sounds like a high bar if you have any children to keep up with any of this. 

To end with, can you share with all of the listeners here, one of your favorite ways to maybe eat some of this food that is really good for you and good for your anxiety, but also tastes great.

Dr. Uma Naidoo: So I love to talk about, and I designed these. This is the fun part of my consultation. Design a nutritional psychiatry treatment plan, but a nutritional psychiatry plate. 

The anti-anxiety plate is based on a list of anti-anxiety foods and the anti-anxiety protocol that I designed that is matches up with recipes.

So one of my favorites is a simple plate. I think about it this way. Half of my plate has leafy greens and colorful vegetables. Maybe it's steamed spinach with good flavorings and a lovely salad along with that. The other component is a healthy fat. I might have some sliced avocado or I have an olive oil dressing in my salad.

Another way to get the fat, nuts and seeds always. For a clean protein, I like things like a baked tofu or even air-fried tofu for crispiness or something like a cauliflower steak. But I flavor these with, I'll use a tikka masala. It's a great way to flavor up something like cauliflower steak or chicken, whichever might be, might be your choice.

That's one of my favorite meals because it has the components, of course, my glass of water, but it has the components that I need. And my legumes give me my protein and the tofu, I added protein. And a little bit from cauliflower, but it also is all the vegetables, all the fiber my body needs and nuts, seeds, the healthy fats.

And for whole grains, I might do a small serving of quinoa, which brings me fiber and protein, all good for the gut and kind of all in balance. 

But really 50% of that plate is the vegetables. 

Jonathan Wolf: Do you have a recipe for that to share somewhere? Can we link to it in the show notes?

Dr. Uma Naidoo: Yes. Cauliflower Tikka Masala is in the recipe section of my book. 

Jonathan Wolf: Fantastic. Well, we will share links on the show notes to the book, and also where any listeners can find out more. I know that you're also sharing some things online, so we'd love to do that. 

We're coming towards the end. I would like to try and do a quick summary if that's alright, and please correct me where I get it wrong.

One of the things you made really clear is that the brain and the body are deeply connected. And so this idea that something I was brought up with, that these are separate, just isn't true. That's not what the science shows. And that interestingly the gut and the brain are deeply connected, and that seems to be so important for understanding things like anxiety.

You told us about this wonderful dopamine reward loop where I'm now thinking about how donuts can be like cocaine and literally like setting my brain on fire and then I crash and then I want it again and we know that's not very good with cocaine and you're saying you can get the same thing with sugar. 

These are foods that have this very freely available sugar which is different from sugar that would be inside some fruit or…

Dr. Uma Naidoo: It's all sugar but it's a healthier source and comes with other nutrients. 

Jonathan Wolf: It doesn’t trigger the same environment that you were talking about.

You helped to explain what anxiety was and what I understood that made it different from being stressed was that there are these very specific symptoms from sweaty palms and your heart racing all the way through to not being able to get out of bed. Your thoughts racing.

And interestingly if you are under a lot of stress or living with anxiety, it actually triggers habits in your brain that can be pushing you to eating this unhealthy food, which is then sort of creating this negative spiral if you're eating that food that's changing your microbiome, changing how you feel.

If you live with this for long enough, this stress, it actually means things like your hunger hormones can stop working. And so there really can be this shift that means that then you're going to end up overeating as a result of this stress because of physical changes that you said that you can measure in the body.

Then I think you shared a whole bunch of really specific actionable advice, which I love. One that I remember is S-A-W, so swap one unhealthy food for something better, add a healthy food into your diet, and then walk. Because surprisingly, exercise isn't just generally good for your health, but it can actually have an impact on your anxiety.

Dehydration can lead to anxiety, I had no idea. So you've talked about liquids a lot. You gave me yet another reason why I can eat dark chocolate after dinner. So it has serotonin and iron. And apparently I just need to add a slice of orange and I'm going to get all that iron. 

Calming tea really does work.I had assumed that that was just something that the manufacturers were selling to convince us, but it's real. 

And then finally, just to finish, we talked a bit about people feeling anxious about their diet and getting really worried. I think what you said is people shouldn't feel that food should be off-limits.

So even the donut that you're talking about, you shouldn't feel like you can never have it. 

Dr. Uma Naidoo: I'm glad you said that. Because if I could just say, if it's your birthday and you want a piece of cake, you really should eat it. I really am opposed to restrictive diets and clinicians who say you should never eat a slice of pizza.

It's about what you eat over the longer term, using these different tools to help you that will help bounce out your anxiety, your mood, potentially even your weight because you're eating healthier rather than worrying about that particular dessert on your birthday or something like that.

Jonathan Wolf: I absolutely love that and I think one of the things that we see with everyone who are ZOE members successfully over time is that they are able to go step-by-step and they're able to think more about what they're adding in and less about the stuff being off limits. 

And I think the other thing, you know, that you mentioned around this is you don't need to avoid all sugar. Just try and see could you be taking it more as fruit and less as Coca-Cola. 

Have faith you're on the right path to make things better, you said. You don't need to be perfect, sort of work on consistency. 

And then finally to wrap up, I just thought you had this great, really concrete example of how hard it is for people to eat well in the modern world. You said, look, plain yogurt is good, berries are really good. So berries in plain yogurt is really good for you.

But if you go to the supermarket and you buy a fruit yogurt, actually the manufacturer will have very cleverly built this thing that sounds like it's plain yogurt with berries, but actually it's this ultra-processed food with loads of added sugar and all sorts of other things.

So you're in this environment where it's very easy to end up eating food that turns out to be bad for you and I think can create this sort of spiral that you're, you're talking about. 

Dr. Uma Naidoo:  That's right. And I know the amounts of sugar in the U.S. yogurt. So I just want to point out, I was quoting that only because you may have a healthier version where you are.

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Jonathan Wolf:  Honestly, it's pretty much the same everywhere around the world.

Uma, thank you so much. I thought that was fascinating. I hope that as you continue to do your research, we can get you to come back again in the future.

Dr. Uma Naidoo: I would love that. Thank you so much for having me. 

Jonathan Wolf: It's a pleasure. 

Now, if you listen to the show regularly, you already believe that changing how you eat can transform your health, but you can only do so much with general advice from a weekly podcast.

If you want to feel much better now and be on the path to live many more healthy years, that's why more than 100,000 members trust ZOE each day to help them make the smartest food choices. Combining our world-leading science with your ZOE test results, ZOE is your daily companion to better health for life.

So how does it work? ZOE membership starts with at-home testing to understand your unique body. Then Zoe's app is your health coach, using weekly check-ins and daily guidance to help you shift your food choices to steadily improve your health. I rely on ZOE's advice every day, and truly it has transformed how I feel.

Will you give ZOE a try? The first step is easy. Take our free quiz to find out what ZOE membership could do for you. Simply go to zoe.com/podcast where as a podcast listener, you'll get 10% off. 

As always, I'm your host, Jonathan Wolf. ZOE & Science Nutrition is produced by Julie Panero, Sam Durham, and Richard Willan.

The ZOE Science & Nutrition podcast is not medical advice. If you have any medical concerns, please consult your doctor. See you next time.

Have feedback or a topic you'd like us to cover? Let us know here.

Episode transcripts are available here.