The best foods to beat the winter blues, end brain fog, and stop anxiety with Prof. Tim Spector

Can what you eat protect your memory, ease brain fog, and lift your mood?

For a long time, we thought the brain was separate from the rest of the body. It's easy to assume that mood, energy, and memory have little to do with what's on your plate.

But in today's episode, one of the world’s leading experts in nutrition, Prof. Tim Spector, explains how your gut health shapes your brain health. From low energy and anxiety today to dementia in later years, he outlines what to eat to protect your brain throughout your life.

Tim shares nine foods to add to your diet, from mushrooms and eggs to tofu and fermented foods, including easy ways to eat more of them, all drawn from his new book, Good Mood Food.

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Jonathan: Can what you eat increase your risk of dementia?

Tim: Yes.

Jonathan: Could you prevent everyday brain fog by changing what you eat?

Tim: Yes.

Jonathan: Can a diet that includes lots of ultra-processed food harm your mental health?

Tim: Definitely.

Jonathan: Is it true that inflammation in the body damages the brain?

Tim: Yes.

Jonathan: To eat for better mood, do you need a lot of expensive ingredients?

Tim: No.

Jonathan: Is eating for brain health complicated?

Tim: No, once you know the principles.

Jonathan: And finally, while writing your new book, what was the most important thing that you learned?

Tim: It was how important the link between our guts and our brains are.

Jonathan: Most people listening will have at some point worried about their brain, whether it’s worrying about their memory fading in some way, feeling we aren’t quite as sharp as we, you know, once were when we were 20, or just feeling low or anxious. And I’ve spoken a number of times on this show about my personal experience with my grandmother getting Alzheimer’s and just how profoundly that affected not just her, but my dad and the whole family. And I think it’s really easy to feel helpless in those moments, like there’s very little we can do, and I was definitely brought up to believe the brain is sort of completely separate from the rest of the body. So it was basically just genetic lottery, you know, were you lucky enough to have good genes or not. So I think it’s amazing to hear from you that this isn’t really true, and your new book, Good Mood Food, it’s really all about this idea that the brain isn’t completely separate and there are secrets, things that you can do that can actually improve your brain health. I think it’s fascinating. It’s very practical. And today I think we’re gonna discuss firstly your principles for better brain health, and then we’re gonna get really practical, right, Tim? And you’re going to give us nine foods to focus on for our weekly shop. Why did you get interested in brain health yourself, and why did you decide to go through all this hard work to write a book about food and mood?

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Tim: I think the thing that immediately prompted me was looking as a scientist at the ZOE studies we were doing when we were improving people’s gut health. We’ve done a number of randomized control trials, the first being what we called the method study, where people followed the ZOE diet as opposed to a US FDA-approved diet. And people that followed that diet got lots of bodily benefits, but the first things we saw improve were mood, energy, and hunger, all within a couple of weeks. Those improved in the majority of people. And I thought to myself, “Well, they’re all brain effects. That’s a bit odd.” And then we did these other studies, the study of the prebiotic Daily30 against a probiotic and against a dummy placebo, and we saw the same results. Then we did a big study of fermented foods where- 6,000 people were asked to take some fermented foods, and we saw the same results. So it doesn’t seem to matter how you improve your gut health. The first signs of that seem to be brain effects, which. A few years ago, we’d have said, “Well, this is impossible. This is just purely placebo.” But we know it’s not, because we’ve, you know, we’ve got control arms. So that made me think, what’s going on between the gut microbes and the brain that can have this really big effect in such a short time? I’ve heard about the gut-brain axis, didn’t think there was that much to it, but now I’m convinced there is. And the more I’ve read about it, the clearer it gets. As you said, we used to view the brain as basically in charge of everything, giving out the orders, and the body was just a redundant thing that followed the orders. It’s completely the other way around. Basically, the brain is there to just assimilate all the signals from our body and give an appropriate response. And that’s why we think the gut is so important, because there’s this huge connector cable between the gut and the brain, which we call the vagus nerve, and it’s a bit like having a massive fiber optic cable that runs from the gut to the brain. And usually most of the brain-body connections are from the brain down to the body, but this one is 80% from the gut to the brain. And what it means is the brain is constantly sampling what’s going on in our guts and predicting how it should respond. And this seems to be the main driver of things like our mood and our energy. If it’s sensing that our guts are not happy, it will send signals to the rest of the body to say, “Slow down. I want you guys to feel a bit tired. I want you to lower your mood so you’re less likely to be sociable.” It turns out that for many of us, it’s the wrong response. We’re getting this every day, and this is not something evolution has geared us up for. So that’s my understanding of why we’re in this mental health crisis, not only in people with, you know, young people, anxiety and depression, but also, you know, the fact that 40% of us are gonna end up having dementia, if we’re currently aged over 50, which is a pretty frightening statistic.

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And that brings in the other reason I was into this, because my mother, eight years ago had a stroke and was diagnosed with dementia and has been suffering with that ever since. And we all of us have known somebody now with dementia or severe cognitive decline, and I think it’s pretty much top of mind now once you, you know, you pass about 50. But the new neuroscience, about the way we understand the brain works, plus our understanding of how the microbes are communicating mean that suddenly there’s this opportunity to help the brain’s health via our gut that has come to light. And so I wanted to have a first stab at trying to introduce people to this subject. Well, it seems very counterintuitive. It’s not obvious that what you feed yourself should actually help your brain, and it shouldn’t be related to your emotions. And to do that, I’ve come up with this very pragmatic way of doing it. You see, introduce it with a, an introduction to the new science and how the gut microbes are doing this, and then 100 or so examples of how you can eat in a way that’s gonna really improve your brain health.

Jonathan: Tim, thanks for sharing that, and thanks for, also for sharing your personal story, and that’s something obviously that we’ve talked about quite a bit off-air. And I think one of the things that you sort of said to me is personally, this in a way has been your own journey, saying that you would like to minimize your own risks of dementia and wanting to really understand what the science says to make sure that you could be doing the best around that. Is that right?

Tim: Yeah, that’s absolutely right. For the last eight years, I, I’ve said, “Gosh, I need to understand much more.” I’ve had various tests myself to look at my, for my risk of dementia and what I can do about it, but I’ve got much more interested now in all the practical things we can all do to reduce that risk and, you know, keep our general mood and things like depression and mood swings at bay as well. And increasingly, it looks like they’re all connected. Psychiatry, for its own reasons, has divided all these brain symptoms into three hundred and fifty or so separate conditions, and I think what the latest brain science is showing us is that they’re all related and the, at most there might be one or two broad categories, and these are just different variants of the same ones. And that’s super exciting ’cause it means that the causes, the mechanisms, and the treatments are likely to be similar, so you don’t have to find three hundred and fifty different causes and treatments. And it’s also telling us that the basic current dogma of brain science, which is all about brain chemical changes, a lot of deficiencies in the brain in terms of neurochemicals being the cause of all mental illness, is wrong. And once you take that step, you realize, well, if that’s wrong, we need a much more holistic approach, and diet and gut microbiome provide that super holistic approach. The other thing I’ve learned is how flexible the brain is. I always viewed it, particularly after, you know, you’d reached adulthood, as something pretty much unchanging, and the latest science is showing us how you can totally change the connections in just a few hours. In a few hours? They’ve shown these experiments with if you blindfold people, just after a few hours some of the bits in your brain will start to be more receptive to things like touch or hearing. So I think our whole view of the brain as something that can’t be changed is wrong. And what I’m realizing is that if we feed our brain the right signals through the right food, we can permanently open up new channels.

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Jonathan: Could you, like, talk us through this? How does what I eat end up impacting my brain and having these effects you’re talking about on, you know, mood and energy and hunger and, you know, long-term, you know, brain health like dementia?

Tim: Okay. Well, let’s give you two contrasting meals. Okay? So say, you know, you’re on the road, you’re in America, you go to a chicken joint. You have some fried chicken in a bun, and you have a Diet Coke.

Jonathan: Can I have french fries with that?

Tim: You can definitely have french fries with that. Okay. And that’s all you eat for a week. Your gut microbes will say, “Okay, I’m getting all this food down here. It’s high in unhealthy fats. It’s... There’s no fiber here. Got some unhealthy meats, lots of additives, lots of chemicals. I’m gonna lose my good microbes gradually over that week, and they’ll be replaced by what we call the bad guys who like the fatty foods and the bad foods, and they produce inflammatory chemicals.” They’re changing the environment of your gut so that more of them can come and grow, and they actually help it, and they change things like the acidity of the gut and the lining and all sorts of things that we’re just learning about. The gut lining itself gets slightly leaky, so some microbes might escape and cause a bit of irritation. And what happens is this inflammatory message, these chemicals trigger immune cells, which then send signals up your vagus nerve to your brain. They tickle other immune cells in your brain called microglia. They send signals to the connections in your brain, the signals of being slightly unwell. Our brain here is blind. We can’t see anything. They said, “We don’t know how Jonathan’s feeling ’cause everything else looks the same, the eyes, the ears, everything, but we’re getting the signal that Jonathan is in some way unwell. So let’s send a signal to the rest of the body to say, ‘Okay, let’s just calm down a bit. Have a nap. Go to sleep. Be less sociable,’ because there could be an infection coming.” That’s what we think is happening when people are having an ultra-processed diet on a continuous basis.

Jonathan: And so that ties back to what you were saying in the beginning about sort of mood being lower and energy being lower.

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Tim: And it might increase hunger as well, because it would just say, “Well, maybe Jonathan’s gonna feel better if we give him more food, you know? Take the mind off the infection or whatever. We’re not quite sure what the threat is. There’s some stress here going on, so let’s just change his behavior a little bit.” Now, if that was just for one day, it’d be fine. It’d be quite a normal reaction. That might happen after having an, a vaccine or something like that. But long term, it’s a... You end up in this depressed or anxious state. Then these pathways in your brain get fixed, and you end up- That is a normal response. Then you also get damage to your cognitive pathways, and so that can accelerate things like dementia. So that’s the scenario of the bad system. Then if you change to a good diet, so suddenly, okay, on your way back you go to Japan or somewhere and you’re, you’ve got a feast of soybeans and pickled vegetables of every description, and you’re getting lots of tofu, and you’re getting lots of ferments. These will gradually depress those bad microbes ’cause they’ll have nothing to eat, and the good microbes are seeing again the fiber will start working again. They’ll break down the fibers in those plants that you’re having, and they produce chemicals. And you might have heard of some of the name of these. Short-chain fatty acids are some of them, and these send signals to your immune system to calm down, just to relax. So these calming signals then get sent up your vagus nerve to your brain. They get passed on like a tag team or like a relay race to the immune cells in your brain, the microglia, and they tell your brain that everything is okay. Jonathan’s back on track, and mood, energy have stabilized. You’re not feeling hungry. So that’s a very simplistic view, but this is what the emerging science is telling us, and this seems to have an effect potentially on virtually every mental health or brain disease that I looked at.

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Jonathan: Tim, it’s a really amazing picture, like the contrast of these two diets, how that affects, you know, my microbes and then through to my brain. And so I think I can sort of see how that might change, like, my mood and my energy. Could you help us understand a little bit how that affects sort of longer term brain health? Because then you also have said, like, a big focus for you is things like dementia, and in my mind that seems completely different. The first is sort of almost like my body thinks I’m sick and it’s changing how I feel, but I don’t understand the dementia side.

Tim: So the inflammation, which is this upregulation of our immune system, once it p- starts to become long-term inside your brain can affect the energy systems of that, so things like your mitochondria. If you’ve heard of those, they’re these little batteries that actually are much more than batteries. They are incredible ancestral microbes that live inside your cells. Because our brain takes a ridiculous amount of our energy just to keep whirring overnight, it takes up to 25% of our energy, and it only weighs three pounds, you know, five kilos. So it’s very energy sensitive. So inflammation upsets the way you produce energy for your brain, and that means that it’s less good at clearing rubbish away. It’s less efficient in all its processes. So long term, that can have a damaging effect- On areas of the brain that can lead to dementia. And the other side which we haven’t mentioned is the fact that if you’re having lots of sugar, so you’re having, you know, lots of donuts on your trip, you’re having sugar spikes which is pushing up the blood glucose levels, continuously stressing the way insulin works, you end up overstressing your mitochondria as well, and they’re the ones producing all the energy that your brain needs to work. So you- the double whammy of the inflammation and having, like a metabolic stress where your sugar levels are perhaps overloaded or, you know, they’re going up and down all the time, that seems to affect the cells in your brain driven by these mitochondria, which then they start to break down and you lose them. So they degrade over time. I’m sorry if it’s getting a bit complicated, but it, the brain unfortunately, I’ve discovered after a co- you know, several years of research, it’s very complicated. But the key, going back again, two real systems, inflammation and metabolism, which is energy, both go wrong in the brain. Long-term, that triples your rate, your risk of dementia. If you’ve got type 2 diabetes, you’ve got three times the risk of dementia than someone who doesn’t, and that’s because the importance of the energy system to the brain. Anything that upsets the efficiency of it is gonna cause it to start breaking down much earlier.

Jonathan: And you were saying that the sorts of, you know, highly processed foods that we’re all used to eating lead to these sort of blood sugar spikes. And when we say highly processed, that would include like, you know, the white rice and the white pasta and the delicious white bread that I, you know, don’t get to eat quite as often as I used to. That’s the sort of examples. So just to bring this into sort of maybe- Yes... more understandable.

Tim: Terms. Yeah, but it’s also sugary drinks, you know, equally those sort of things. And 25% of our energy goes to just keeping our brain ticking over. In a five-year-old infant, it’s 60%.

Jonathan: So Tim, I think I’ve got a much better understanding now of why what I eat really can influence my brain, my mind, how I feel. In your book, you discuss four principles for better brain health, and I’d like to talk about them in just a second. But first of all, I’d just like to say, you know, if someone improves their diet in line with what you’re advising, like what benefits can they expect?

Tim: Well, I think we know from the trials that we’re doing is the first things you will notice is levels of fatigue are reduced. So y- this common complaint of tiredness, which has generally been ignored by the medical community, because it’s subjective, is, you know, what many people now are suffering around the world, and that’s the first thing that will improve when you improve the quality of your diet and you cut out some of these bad things. You’ll find an uplift in mood. You won’t have those mood swings as much as you used to, and reduced hunger, so you won’t be craving foods like you used to at different times, craving snacks, et cetera. That’s for people who don’t necessarily have mental health problems. If you see these as a spectrum, you know, with particular mood, everybody has bad moods at some point. Everyone has tiredness at some point. But some people have them all the time, and some people have it to such an extent they can’t get out of bed or they’re in hospital. What we’re seeing is everyone at whatever stage they are will get some improvement in these symptoms, ’cause they’re essentially symptoms from the brain to the rest of the body. So what you’re doing is you’re just changing that signal. You may not be fundamentally... You know, it’s not like you’re gonna cure everything. But all our studies show you can dramatically reduce the symptoms by changing the signals to the brain. They’re the first things to happen, and if you do this long term, then you will start to reduce your risk of all of these conditions, and I think that’s really important. And we’re talking about all brain conditions here. All of them have been shown in studies to have the similar mechanisms and therefore, although we haven’t done the trials yet, everything’s pointing in that right, that direction.

Jonathan: So can moving to a really gut healthy diet make a difference for people with, you know, serious mental health diagnosis like depression?

Tim: Yes. So there’s one classic study called the SMILES trial, where they took individuals who had existing depression, hadn’t responded well to an antidepressant. They were still on the antidepressant, and in addition to that, they either gave them a standard diet or a gut-friendly focused diet, which was high in fiber and plants, a bit like the ZOE recommendation. And those that had the gut-friendly diet had a significant improvement in all the symptoms of anxiety and depression, and those effects were greater than that you would get with an antidepressant alone. So we had remission rates, people... About 30% of people got rid of all their symptoms.

Jonathan: 30% of people got rid of all their symptoms even though they had depression?

Tim: Yes. It wasn’t a long-term study, so we don’t know what happened to the long term, but it was extremely encouraging, ’cause nobody before that study believed that diet did anything that wasn’t just trivial or placebo.

Jonathan: But this really shows you as an example, you know, with a randomized control trial, so the sort of gold standard, right, in science that— But what you eat really can shape your brain and serious brain symptoms.

Tim: Yeah, and if you add all the other studies done in other mental health problems, everything pointing the same direction.

Jonathan: What about dementia?

Tim: The studies of dementia epidemiologically are really quite clear. We know that type 2 diabetes is associated with a threefold increase in dementia, and we know that poor diets are associated with a similar increase. So whether or not you develop type 2 diabetes or not, it’s the diet that’s the problem.

Jonathan: So poor diet is like a threefold increase in my risk of dementia?

Tim: Yes. Everything suggests that poor diet is a major reversible factor for people with dementia. Now, once you’ve got severe dementia or Alzheimer’s, the studies are less impressive in terms of reversing it. So I think most of the good studies are on people with early cognitive decline. Those really early stages where it’s not, you wouldn’t get a formal diagnosis. But there’s large amounts of studies showing that if you improve those people’s diets, you will improve cognition and slow down the rate at which you’re losing it.

Jonathan: Got it. But it’s more about prevention of getting dementia or prevention when it’s at a very early stage rather than being able to really change it if I’ve already sort of having s- you know, significant symptoms.

Tim: That’s what the data currently show, yes.

Jonathan: So I think you’re painting a picture for like pretty amazing benefits, Tim. So let’s talk about those four principles. And the first one you mentioned, which won’t be a big surprise to our regular listeners, is eating 30 plants.

Tim: Yeah, it’s the old perennial. But just ’cause we mentioned it before doesn’t mean it isn’t important, and 30 plants is a target to aim for. It could be that 40 is better. We’re currently exploring that in the ZOE data. But the point is, if you eat a diversity of fibers and plants, your microbes are getting the maximum ability to flourish and produce lots of chemicals, and I think that’s part of what we’re understanding is here, that the more good chemicals your microbes produce, the better the signals going to your brain and the more chance you have to produce anti-inflammatory chemicals as well, which will dampen down the immune system. Also, by eating a diversity of these pl- 30 plants, we know from our ZOE studies that you’re gonna get your 30 grams of fiber, and most of us are getting close to half that. So that’s why it’s key in my cookbook as well.

Jonathan: The second one you have is avoiding high risk ultra-processed food.

Tim: The epidemiology is quite clear from the observational studies. People who have large amounts of ultra-processed food in their diet end up with more mental health problems, everything from anxiety to depression to psychosis and dementia. So cutting that down is really important. And at ZOE, we’ve now focused this on the worst offenders rather than 60% of all our food. So the worst ones are the ones that have all the chemicals in it, the additives that are harmful for us. They make us overeat, and they’re also really easy to swallow. So particularly for things like teenagers, young people with anxiety problems who might be looking for these foods because it’s the easy option, just going without them for a couple of weeks can make a huge difference.

Jonathan: And Tim, we did a podcast with you and Sarah Berry on ultra-processed foods, you know, quite recently going into all the details. But for anyone who hasn’t listened to that, is it just about additives? Is that the thing that is causing the damage to our brains?

Tim: No. You need to take a holistic view about ultra-processed foods. So additives are one part of the problem. Some of those additives might affect our gut microbes. Others might directly affect our bodies. But it’s what they’re not getting, so it’s the lack of fiber, the lack of nutrients, lack of any sustenance for your gut microbes is also important. Then you’ve got these other factors that trigger obesity, make you overeat. Then you’ve got the speed of eating, so they’re messing it up as well. So it’s a composite of many things, ultra-processed food, and that’s why, you know, we’ve developed a new score to work out what the worst ones are. But easiest thing is to try and avoid as many as you can.

Jonathan: Your third is incorporate fermented foods.

Tim: As people know, I’m a big fan of fermented foods, and we now understand the mechanism by which they work, so it’s slightly different to just getting your 30 plants and the fiber. There seems to be a separate anti-inflammatory effect to these foods, so that if you’re having three to five portions a day, you’re likely to be able to reduce your blood levels of inflammation and also your gut inflammation. That means the signals going to your brain are gonna be better, and we know that if you can reduce inflammation in your brain, you can reduce symptoms of anxiety, depression, and long-term, your risk of things like dementia.

Jonathan: And your final, your fourth principle about brain health was give your gut a break. What does that mean, Tim?

Tim: It’s like we all go to sleep every night, and we, we’re told we need eight hours sleep and try and keep it consistent with our circadian rhythm. Our body needs to repair itself, and our gut microbes need to do the same. If you’re constantly eating, as many people with mental health problems do, well, they don’t... ’cause they’re not sleeping well, they accentuate the problem. Your gut microbes don’t know whether to rest or play, and the repair teams don’t get a chance to come out and clean up your gut lining, so you’re making it worse. We did something called The Big IF Study, if you remember, Jonathan, where we looked at over 100,000 people, tell them to do some time restricted eating, which is just leaving 12 to 14 hours without food, and we got improvements in mood and energy in the majority of people. So again, showing us that there’s some brain effects, improve mental clarity. And I, for this podcast, you know, I make sure I have a good overnight fast, and I actually perform better than if I had my big full English breakfast before coming on and talking to you.

Jonathan: So you’ve had no breakfast at this point?

Tim: No, just coffee and tea.

Jonathan: You’ve got all of your different advice, Tim, and you’ve nailed it down to just, like, four principles. Why has this made it into the list for my brain health?

Tim: I was surprised at the results of our study. 150,000 odd people, if they’re telling me that, you know, having done this, time-restricted eating for two weeks, they felt mentally better and had more clarity and their mood was elevated, you’ve got to listen to that. And I just think we’ve been very bad in medicine about asking people about mood and energy. We know that time-restricted eating improves your gut lining and your gut microbes are better balanced. The signals of inflammation are reduced, and there’s less microbes escaping from our gut. Everything is pointing to that being helpful.

Jonathan: If I understand what you’re saying, you’re saying that what I experience as tiredness and like low moods or just feeling a bit down or, you know, not at my best, is actually a measure of the fact that I’ve got this low-grade inflammation in my body, and so I’m experiencing that as the fatigue and feeling a bit low. And I think you’re also saying that amazingly... going from maybe only giving your body eight hours, not eating, to suddenly 14 could actually reduce that inflammation in just two weeks to such an extent that my mood actually changes and improves?

Tim: Yes. It seems extraordinary, but that’s essentially what we’re saying and what our study suggested, that it is happening. But I think you’ve got to distinguish perhaps inflammation in your gut from the rest of your body. So when you’re feeling tiredness or fatigue, it’s probably just your brain telling you that. It doesn’t mean your muscles are actually useless or floppy or not working. It is your brain sending those signals, telling h- your body how to behave. So you’ve got to think of it as, you know, the wrong signals coming into your gut, the food, inflaming your gut. That goes to your brain. The brain then predicts the wrong signal, and that signal then gets passed to your body, and then you’re tired and useless. But there’s nothing wrong with the rest of your body. So if you switch off, you change that pathway, then you can be restored.

Jonathan: It’s really amazing. It’s like the reverse of how I think we naturally experience it.

Tim: Yeah. You’ve got to realize the brain is this, in this isolated little box. It doesn’t really know what’s going on. And the gut is a key player in that. It’s telling us, you know, how Jonathan’s feeling is through the, through those microbes sending those chemicals up into the brain. And then the brain just predicts how Jonathan should be feeling.

Jonathan: The book has what? Like 100 recipes in it?

Tim: Over 100, yeah.

Jonathan: And I know that you wrote this book as a recipe book ’cause you wanted to make it super practical.

Tim: Another idea of the book was to talk about comfort foods. You know, when we’re feeling a bit down, we often like to go back to those foods, and it reminds us of our happy days or childhood or whatever it is. And so what we’ve done in the book is taken a number of those and ZOE-ified it, you know, made them more healthy. So there’s one in there which is fish and chips. And of course, yeah, they’re not the same chips, and the fish is a healthy fish. But we’ve still got the peas in there and other things that are good. We’ve got a mac and cheese, which is not that bright orange one, but it’s a more natural version of that. We’ve got a spaghetti bolognese, which is a really healthy way of switching out the mince for lentils and capers. So there’s a number of these, plus some nice desserts, brownies and things which are made with sweet potatoes, pavlovas which are made in a really healthy way, things that you wouldn’t think you can make them healthy. So they bring a smile to your face when you look at them. You know, in the past it would be a naughty treat. We’re making it so that you can enjoy it, you can uplift your mood, but at the same time, you’re also helping your gut microbes.

Jonathan: Brilliant. Today what we thought would be fun was to pick out nine foods to add to your shopping list that could actually improve your brain health. So I’ve got a list of nine in front of me, and Tim, I’d love, as we go through, just explain why. And the first one was a bit of a cheat, because the first one is plants. Why are plants in particular good for brain health, and do any of them count as super foods?

Tim: All plants are great. Just to remind people, it’s a fruit, a vegetable, a seed, a nut. It’s a herb. It’s a spice. It’s things of different colors. I think of a plant as a different chemical composite of something you grow in the earth. And these chemicals then provide sustenance for our gut microbes, and the greater diversity, the better. So that runs through the cookbook all the time in that I’m trying to pack in as many interesting plants into those dishes, that liven up the dish, but also give maximum potential to grow all the good microbes you can. And the more the merrier. So most of them have, you know, eight to 10 plants in them. There’s lots of herbs. There’s lots of spices. And we’re increasingly realizing that cuisines that have lots of herbs and spices do really well for gut health.

Jonathan: Much of the rest of our list, you know, comes from plants. Let’s start with number two, which is mushrooms, which are a plant, right?

Tim: They’re not a plant, actually. They’re their own kingdom, part of fungi. So we have animals, plants, and fungi. We mustn’t associate them with just another plant because if you’re eating mushrooms, you’re getting all sorts of interesting chemicals you can’t get in other fruits or vegetables. So the cell wall is completely different, and the fibers are very different, and you’re getting lots of protein, lots of fiber. And there are studies showing that if you can get three portions of mushrooms in your diet, you can actually reduce your risk of dementia by about 25%.

Jonathan: By 25%?

Tim: Yeah. These are long-term observational studies. These, this is from Japan, but, you know, it convinced me.

Jonathan: And how much is three portions of mushrooms?

Tim: It’s a handful. That’s the average of what they studied. There are other ways to get mushrooms other than, you know, fresh mushrooms. So dried mushrooms are probably even more beneficial because they don’t have all that water in them. So you can add those. It’s one of the reasons we added eight different types of mushroom to The Daily30. So you can have that every day, a small amount of mushroom in there, which, you know, could be, turn out to be really critical for brain health. And in the recipe book, if you’ve got excess mushrooms, you can ferment them and have a fermented mushroom pate. So instead of, you know, a really unhealthy meat pate, you’ve got something that tastes pretty similar and exciting, and you can have that, you know, on a daily basis in a really concentrated form. I’m always trying harder to get more mushrooms in my diet.

Jonathan: And Tim, do you need to eat like a really exotic mushroom? Because I feel like until a few years, there was only like two types of mushroom that I could see in the supermarket, and now they have like a fancy one, but it’s twice as expensive.

Tim: There’s no comparative data. There are lots of studies of these fancy ones like maitake and lion’s mane and other ones that show they have some benefit in short-term studies. They’ve never compared it to good old button mushrooms. If someone offers me the good expensive ones, I’ll definitely have them in restaurants... And we have them in the Daily30, but I wouldn’t go out of my way to only buy those at the moment. I think any mushroom is good, and a variety is probably better than just having one. We’re just not used to eating them as well, so it’s a bit like changing our habits and, you know, there’s another recipe in here for a bolognese where use lentils, but mushrooms as well. The mushrooms are sort of a substitute for meat. So if you’ve always got them in the fridge, then, you know, you will end up using them more and more. Full of protein, full of umami flavors, and knowing actually it could be delaying or r- you know, reducing a risk of dementia is pretty cool.

Jonathan: Let’s move on to number three, eggs, which I think may be a surprise to a lot of people because I definitely remember times when I’ve been told that eggs are terrible for me.

Tim: It goes up and down. And currently, I would say eggs are back in favor, as long as you don’t overdo it. So we think up to about equivalent of one a day, so seven a week. Generally regarded as a really good nutrient because eggs, a bit like the animal form of seeds, they’ve got everything to grow a young embryo up into a full adult animal. And so if you wanna make sure you’re getting all those nutrients, having some eggs in your diet is actually really good for your brain health. And there are a few observational studies to show that people who do have a moderate amount of eggs in their diet have better brain health than people that don’t. So I’ve got plenty of egg recipes in there, frittatas and tortilla, things where you can use the eggs to, as an excuse to put lots of vegetables into that same dish.

Jonathan: And eggs are high in cholesterol and fat. Isn’t that all supposed to be bad for our brain?

Tim: They are high in cholesterol and fat, but it turns out they’re not bad for you. So again, this is old-fashioned science that’s 20 years out of date now. It all depends on the global amount of what you’re getting. So cholesterol itself in foods is not bad for you. There’s plenty of cholesterol in lobsters, but nobody says, you know, lobsters are deadly for you. So eggs are fine in moderation and great source of protein as well, and if you’re not eating lots of meat, it’s a really good alternative.

Jonathan: Let’s move on to number four, and here you talk about foods that contain omega-3s.

Tim: Omega-3s are important for brain health. It’s much better to get it through nutrition than through supplements because there’s probably other benefits from those. And there’s a nice way to remember which fish have the most omega-3s. They tend to be the smaller fish, and if you remember SMASH. You have sardines, mackerel, anchovies, salmon, and herring. The ones I particularly favor are sardines and anchovies. They’re the smaller ones, and the smaller the fish, generally, you know, the more of the little algae they’re eating that have these high omega-3 levels in them, and the less mercury and other heavy metals that some people are w- increasingly worried about when you... If you’re eating lots of big fish. So you get real bang for your buck with these small fish, and they’re often the cheapest you can get. I’ve got lots of recipes where I incorporate in this. My favorite one is a pasta with courgettes and capers, and you add in either your sardines or your anchovies to it, and you add a bit of lemon zest on top. It’s just a fantastic dish. You can’t believe it’s that healthy and good for your brain.

Jonathan: I was gonna say, I wouldn’t really know what to do with a sardine and an anchovy. Like, the only thing I could think is like I could, you know, stick the anchovy on the side. Toast. ’Cause they’re s- like small fish, so they don’t fit into my mind of like it’s not the big centerpiece of the meal.

Tim: You incorporate them into things like a salad. A Mediterranean salad, would have anchovies in it with eggs and olives and capers. As I said, you can put it in these pastas, as in the book. I eat it with a sourdough rye bread, rub tomato on it and then you put your anchovies, on top, and you have that as a snack or a starter or a lunch. You only have to have, you know, these a c- a couple of times a week and you’ll really boost your omega-3 levels. I did this and retested myself and suddenly, you know, I went from being borderline low to, you know, I increased by 30, 40%.

Jonathan: That’s brilliant. So the next one to me feels like even further out of my comfort zone, ’cause it’s tofu, which I definitely never grew up eating.

Tim: Well, tofu is one of the cheapest, easiest ways to get high quality protein into you. So it’s made from soybeans, and it’s super versatile. So I’ve used it in everything from curries as an equivalent for things like cream. So yes, you can fry it up. I’ve used it in one of the recipes as an alternative to chicken in a chicken soup. So essentially it does the same role. It will mop up all the sauces and provide you with that protein without it being an animal product. And there’s also a version which I use quite a lot in the cookbook called silken tofu, which I hadn’t heard about much, which is a more liquid form of tofu, and you get it in a little carton, like a carton of cream. And this is super versatile, so you can, y- if you want to boost the amount of protein you’re putting into a veggie dish, very easy to add this, thicken sauces. And I’ve got a nice dish called my spiced tofu scramble, and you mix it with mushrooms and you put it on toast. So it’s like a, another way of doing sort of instead of eggs and things like this. It binds things together. I often get the smoked tofu rather than the plain one. I think that’s a bit more interesting, unless you’re gonna, you know, spend a lot of time marinating it. But that will go on the top of salads and you mix it with a bit of chili, bit of garlic, olive oil. You know, it, it’s a lovely addition.

Jonathan: And why is tofu so good? I- or is it just that it’s better than the cream or butter or whatever that you were talking about?

Tim: We don’t exactly know. I mean, it’s obviously, it’s pack- it’s really just super high protein, and it’s got the other bits of the soybean in it. And there are studies, a lot of studies in Asia showed people who have a lot of tofu do get less cancers. So it could well be that there are other plant chemicals in there, so-called phytoestrogens, that have a, some anti-cancer effects that we don’t totally understand. So the balance is all good. You know, we can’t prove all these things, but in general, it seems to be pretty good for you. And there are some Asian studies as well that have shown it’s associated with brain health. So it’s something that we should all incorporate into our diet. And it could be that you have a meat dish and you just wanna add in a few bits of tofu to supplement it or, you know, you wanna, you’ve only got a small amount of meat and you wanna make it go further. You know, it’s so versatile. I, in the book, I swap it in and out for chicken, for example.

Jonathan: And so if someone’s listening to this and saying, “Oh, but tofu, le- you know, that sounds really difficult. I don’t know what to do with it.”

Tim: It’s, it comes in a pack, bit like a square pack. You open it, you slice it up, and, you know, it takes 30 seconds to put it in a pan. You fry it up. It, there’s nothing really simpler. So don’t be frightened of it. Go and experiment. And look out for the liqui- the more liquid one as well, which you can just add to sauces and things.

Jonathan: All right. I am going to number six, which is herbs and spices. Why do they deserve a place in a brain healthy kitchen as opposed to just taste good?

Tim: They provide two things. So there is nutrition for our gut microbes because you’re getting a diversity. Most spice mixes are at least five different plants in there, and they’re the concentrated bits of the plant. So that means as well as the little bits of fiber, there’s all these polyphenols in there. And these are these defense chemicals. And there are lots of studies now showing that if you can increase the amount of polyphenols in your food, that has a beneficial effect on our brains. A lot of this is from animal studies. At the moment, we haven’t got huge definitive studies. There are some studies showing improves gut health, but I put them in because also I think the more you can stimulate your taste buds, the more your brain gets engaged as well. And I’m sure just the smell of things, you know, once you start putting lots of mixed spices in your food, it just livens everything up. And so it certainly gives me a good mood, if I’m cooking and I’m getting those mixed spices in there. So I’m always trying to spice up all my dishes.

Jonathan: Are there any particular spices that are most likely to be good for boosting my brain and my mood?

Tim: So curcumin is one which is the main ingredient in turmeric, and saffron has also been shown in a number of randomized studies to improve brain health. All these studies are in their infancy. We have to take them with a pinch of salt as well, as well as spice. But I like them because they also add a lot of color and we eat with our eyes, and if something looks great on the plate, generally, you know, we feel uplifted. And so the book is full of colorful dishes and that vibrant colors, a lot of them come from these exciting spices. And having arranged them, you’re giving yourself a chance that they could also be having some other benefits.

Jonathan: Amazing. Let’s move on to number seven, which was mixed seeds and nuts. Why did they make it into this list?

Tim: I’ve put mixed seeds and nuts in here because they give you a range of things that you might not have thought were good for you. So they give you lots of fat, okay? And in the past we said fat is bad, but actually these are all really good fats. These are healthy fats, and our brain is made up of fat.

Jonathan: Our brain is made of fat?

Tim: Yes. Your brain’s made of fat and, you know, we know that all these fats are really good for it. You know, the omega-3s we talked about from fish fats, fish oils, and, of course all the oils that come out of nuts and seeds. And it’s just that in many countries the guidelines haven’t kept up with the science. We can’t live without fats. These are absolutely essential for the repair of our body, our normal function, how our brains work. And so this is another way to get them in you. But also, as well as the fat itself, with nuts and seeds you’re getting the coating of everything in it. You’re getting all the micronutrients in those seeds to make sure that our brains have, you know, the manganese, the zinc, the selenium, all these things you don’t normally think about. They’re getting them because they’re in these perfect amounts in these little seeds and nuts, and that’s why having a variety of them makes sure you’re gonna get a really good balance. So I tend not to go for any particular one. I think we’re much better off trying to have a whole variety of them.

Jonathan: And what dishes do you add them to? ’Cause I tend to think about, like, nuts as a snack or alternatively I do tend to put them now on my breakfast along with all the other things I’m putting there. But I don’t think I’d ever think about adding it to lunch or dinner.

Tim: You might put some on your avocado toast or your smashed pea toast. You know, a bit of extra texture to a salad can help. They go in soups quite well as well. A lot of this book is showing there are other ways of doing it and, you know, just sprinkling on top of the finished dish, you know, can look great as well. And even some desserts.

Jonathan: All right. Number eight, beans and lentils. We don’t cook with beans or lentils that much in the UK or the US. Why are you such a fan?

Tim: Firstly, they’re a great source of both protein and fiber, which is unusual. And they’re incredibly versatile, so you can put them in nearly anything. There’s lots of recipes here where you change a traditional spag bol or a chili con carne or whatever, and you’re just replacing meat with these. So they’re a perfect replacement for many of these foods. You could also add them to salads. They’re very cheap. You can buy them in cans. They’re pre-cooked. You just tip them into your salad, your casserole, your dish, and virtually all the recipes I’ve got contain some beans or lentils in there.

Jonathan: In my mind, you have to soak them for hours and then you have to sort of cook them for a really long time. And so they are quite impractical for, you know, my lifestyle and I suspect from many other people’s.

Tim: That used to be correct. And I used to think exactly the same, but I’ve got a big drawer full of dried beans and lentils that I never use. And but the one I do use are these where you buy cans of them or that are pre-cooked, or you can buy sachets of lentils that are pre-cooked, sometimes even mixed ones. So you get even more different varieties. So all that overnight cooking and fuss, which we were brought up on is it’s all gone. We don’t need to do that now. And you can get them in mixed ones. So I like cans where you get five different types of bean in one, which is for your gut microbes is a real treat. If they’re like butter beans, you add them with some leeks and some fennel. You might add some sauerkraut and you’ve got a delicious hearty lunch. You know, it comes in its own juice. It’s cooked in its own juices. And for salads, generally, I like to rinse, get rid of that extra liquid. My wife doesn’t like it. Finds it a bit too slimy. Don’t throw it away if it’s from things like chickpeas. So you do chickpeas out of a can, and you can use the extra juice in there as a substitute for egg whites. So there’s a recipe in here about doing, my mom’s favorite pavlova, which she used to make for me, but it’s a healthy way of doing it. And you actually increase the fiber and everything and reduce the sugar by whipping up all the juice of the chickpeas or garbanzo beans as they’re called in America. And you’ve got this really thick glue that actually can bind together your meringue. If I had to pick one favorite, that’s one of my favorite dishes. So beans are so versatile in all kinds of ways.

Jonathan: And so last but not least, we come to fermented foods. Obviously, we’ve recorded podcasts talking about fermented foods in detail. What in particular should people be looking out for in terms of products and how they should be using them if they’re focused on their brain health?

Tim: So it’s important for people to try and get three to five little portions of ferment. So small amounts often. One way to add a ferment is to swap your stock cube for a miso paste. Miso is made from fermented soybeans and salt and gives an amazing umami flavor. So that’s one thing I never use stock cubes anymore. I only use my miso paste, which I make myself. There are lots of soups in here where you can add those ferments to the soup, adding it in salads, putting it on the side. Instead of cream, you might add a bit of kefir or so- plenty of them have yogurts, added topping everything at the end. So really any excuse to add a ferment which not only adds extra flavors to the dish, but also makes it even healthier for you. And the more ferments you’re having, the more you’re reducing inflammation in your body.

Jonathan: And if I put fermented food into a dish that I’m cooking and part of the fermented food, right, is it has these live microbes, does that mean that I kill it and therefore it’s no longer, you know, counts as a fermented food for my diet?

Tim: Great question. You certainly do kill it. Everything above sixty-five degrees will kill most microbes. But we now believe that there are many fermented foods that still have a health benefit even when they’re being killed. And this is either because the body of the microbe is still having an effect on the immune system, so the cell wall or the chemicals that it was producing are still alive and they’re still going into the food which is going into your gut. It may not be as much as live, but it’s pretty much as good.

Jonathan: Got it. And so it’s the act of being fermented seems to create a lot of nutrients. Even if you kill the live microbes, you’re still getting-

Tim: Their juice...

Jonathan: Their juice.

Tim: In that juice, there are thousands of chemicals that have been created by this whole process and you’ve got the debris of the microbes themselves which can have an effect on your immune system. So which, this is all very late new science, but we call this postbiotics. And so that’s why we shouldn’t be frightened of adding lots of ferments to our food even if we are heating it up and that’s a lesson that runs again through the book.

Jonathan: Tim, thank you so much for taking us through all of that. Imagine we have a listener who’s feeling a bit overwhelmed at this point, right? They want to eat better for their mental wellbeing, but they aren’t doing many of these things. It all sounds a bit too much. So if you’re gonna say like if there’s one thing, one place to start, what would that be?

Tim: Don’t try and do too much. Do it for two weeks. Make a note of your mood and your energy, how your brain is working, your brain fog and I think you’ll see an improvement and you’ll want to do this for the rest of your life.

Jonathan: Thank you, Tim. Let me try and do a summary and let’s see if I can manage to keep this all in together. The thing that I’m most struck by is this idea that if you’re on a poor diet, you have a threefold increase in your risk of dementia. So it’s, like, huge. We’re not talking about little impact. We’re saying it’s enormous. Like, what you’re eating has so much effect on your brain. If you’re feeling tired or you feel like you have a low mood, actually that’s a measure of inflammation in your brain. So you are directly feeling that. That’s obviously not very good, but you’re also saying, hey, there’s stuff that you can change by what you eat to reduce it. You gave us those two, like, sample diets, I guess, to say what might happen. You said if you’re eating, like, this fried chicken for a week for, you know, lunch and dinner, what happens? You’re saying you feed all the bad microbes, and so your gut changes. And as a result, suddenly you’re sending all of these signals up this great big vagus nerve sort of cable to your brain saying, “you know, your gut health is bad, you’re sick.” And then your brain then sort of signals the rest of your body, you know, things are bad, right? Have a nap, be less sociable. You might have an infection, and you end up becoming depressed or anxious. On the other hand, if you’re eating a really brain-healthy diet, then you’re starting to feed all of these good microbes, and they start to create all of these different nutrients. And you mentioned the sort of short chain fatty acids is one that calm down your immune system, send messages to your brain that everything is good, and suddenly it’s the reverse, and you feel happier and with more energy. And you see that in all the trials that you’ve run. So the first sign of improved gut health is normally things in the brain: mood, energy, and hunger. And in the long run, dementia is the same problem. This inflammation upsets your brain, and it makes it harder to clear away the rubbish, you know, in your brain, and eventually you end up living with dementia. And then in the second half, I think we really talked about what we could do. You had sort of four principles: eat 30 plants a week, avoid high-risk processed foods, incorporate fermented foods, give your gut a break. And then we talked about sort of nine specific things, and I would say seven of them are maybe on top of what were in your principles. Mushrooms, three handfuls a week. There’s real evidence for that for your brain. Eggs are actually good, not bad, but you said up to seven a week. So like an average of once a day, not three a day. Omega-3s, you get these from fish, and in particular you were saying you really like sardines and anchovies. They’re really easy to get into your diet, and they’re particularly high in these omega-3, which is a fat. Tofu, don’t be scared of it. It’s one of the cheapest and easiest ways not only to get high quality protein, but actually all of these added benefits for our brain. Herbs and spices, they deliver a lot of concentrated plant diversity, and so it’s one of the ways you can get to 30 plants a week. Your recipes are full of it. Mixed seeds and nuts, full of good fats because my brain is made of fat, which I had no idea of. So makes sense. My brain is made of fat. I probably need some good fats to go in there. And then lastly, beans and lentils. You can just buy them pre-cooked and ready to go. And so actually, instead of being really hard to use, they’re one of the easiest things to create one of these recipes.

Tim: Yeah, you did it. Very good.

Jonathan: And if you want to learn more, then of course you can go and get the book, which has all of these recipes, and I’m excited to go out and try some of them this weekend.

Tim: I’ll give you one.