ZOE’s best health tips of 2025 - Part 2

0:00Welcome to ZOE Science & Nutrition, where world leading scientists explain how their research can improve your health.

0:13Welcome back to part two of our 2025 highlights. The moments that changed how we think about our health and gave us practical tools to feel better every day. Today, you'll hear what happened when I put my own breakfast under the microscope, how arthritis symptoms were reversed in a groundbreaking trial, and we finally get a scientific answer to the question, does cheese really cause nightmares? But first, a person who has arguably pushed the boundaries more than anyone, Brian Johnson. Brian has dedicated his life and his body to testing cutting-edge health interventions to slow down aging. His meticulous approach to sleep, diet and exercise has sparked global debate and raises a question that matters for all of us.

0:59How much should we experiment with our own health? I began by asking him how he developed his unique way of living. We wanted to approach this question scientifically, and so I hired 30 medical professionals. And we went through this process where we evaluated all the scientific literature on healthspan, lifespan. We tried to grade the evidence that we could identify. Do we think, for example, a given therapy, let's say it slows down the speed of aging or reverses aging damage to a certain degree, do we believe the evidence? And then we stacked ranked all the evidence and said, okay, we have our list and let's just start with number one and let's do that therapy or that measurement.

1:39And so we had a firm principle that we would do everything based upon measurement and scientific evidence. And so I became the most measured person in human history. There's more data on my body than anyone before me. That's amazing. And we've just gone through this process of measurement, application of the science, and again and again. And I think it's possible that they have the best comprehensive health markers of anybody in the world. You know, I take 50 different markers from my sleep quality to my inflammation levels to uric acid to muscle to fat to take any marker. We're going to share this actually in the next coming days.

2:20But it's really a contemplation of like what does health look like? and comprehensively from how you sleep to what your microbiome looks like to your biological age, your methylation patterns. So we really have tried to just do this by the data and numbers and with as little storytelling as possible. And Brian, when you say the best possible markers, do you mean the best possible markers for someone of your age? Or are you saying that like they're better than, you know, my 16 year old son? And so in every biological age marker, there's typically an ideal age. So for example, like in grip strength, as you grow older, you increase in grip strength capacity, that you hit a certain age, you decline in grip capacity.

3:04And that is true for a lot of things. That's your cardiovascular fitness. It peaks at age 18 and then declines from there. And so we've tried to identify the peak health level of every category of every marker and we try to peg that. So we say, what is peak cardiovascular fitness for an 18-year-old? And then how do I achieve that? So for example, my cardiovascular fitness is equal to top 1.5 % of 18-year-olds as measured by VO2 max. We completed a test today looking at oxygenation of muscles. And so that's also a marker of age. So my oxygenation of my muscle is the top 5 % of 18-year-olds, elite swimmers.

3:43So we try to find peak levels and then peg my markers to that as best we can. If I understand, Radha, you are saying that yes, you are better than my 16-year-old son basically on all of these markers. Yes. I mean, if you basically said, because a conventional wisdom would say a 47-year-old could never be as healthy as a 16-year-old. Now, in certain regards, that's probably true, right? They have the anatomy of a 16-year-old, I have anatomy of a 47-year-old, and there's just some things our technologies can't do today. However, if you compare the 16-year-old and me on these markers, inflammation, sleep quality, cardiovascular ability, bone mineral density down the line, it's possible my health markers are in fact better than these 16-year-olds.

4:26That's amazing. Listening to Brian, I was struck by the contrast between his extreme routine and the much smaller health experiments most of us might want to try. My Zoe co-founder, Professor Tim Spector, Brian and I shared a really honest, useful exchange about what's safe, what isn't, and where to start. One question I think a lot of listeners will have listening to this is, is it safe to experiment on my health? So how should people, you know, if you were going to advise anyone listening to this, thinking about experimenting with their health but wanting to do it safely, what would you be saying, Tim?

5:00I think it's reasonable to explore, particularly, you know, with, say, sleep, exercise, and food. if you do it for short periods of time and you're not going to overdo it it's probably reasonably safe if you don't have any other medical conditions and you're fairly young and healthy everything i believe in now is about self-experimentation because everyone is different and learning what you know what sleep is good for you what how much exercise is good for you what the right diets you know what are personalized to you or you should be on a high fat or a a high-carb diet. These all require some self-experimentation, you know, if you don't have access to things like Zoe program.

5:41But I think I would do it for short periods of time. You know, the danger is if you overdo it. And in areas we don't fully understand, and I think the gut microbiome was one, certainly when we did this 10 years ago, we didn't understand quite how harmful some of these practices could be. But I think we should But really, yeah, everyone should be encouraged to some extent to do self-experimentation. Do you agree with that? Yeah, I mean, life is an experiment. So whether someone is actively opting into an experiment, they are experimenting every second of every day. So when you decide to go to bed, you're doing an experiment.

6:19When you choose something from the menu, you're experimenting. Like every decision you make is an experiment. So the question is whether you have data just to inform you of the results of your experiment. But what I think is really cool is that we've learned that just with food, if you just record how you feel a few hours after eating it in a notebook or something, you can get a pretty good idea of whether that food does agree with you or not. And these are things we never thought of before, because we always assumed we were all the same. We all respond to exercise, food, and sleep the same way.

6:51But, you know, the experiments Brian's doing are very methodical, very technical. but I think everyone can just make a mental note to think about how they feel. How does it make them feel? That idea of simply paying attention, noticing how you feel after you eat, move or change your routine, has really stayed with me. It's such a low effort habit, and yet it can tell us more about our health than we realise. And it doesn't just apply to food. Brian told us that sleep was one of the biggest levers he's found for improving his overall wellbeing. So with that in mind, I turn to someone who knows this better than almost anyone.

7:26World-leading sleep scientist Sophie Bostock. In this next clip, she explains why good sleep doesn't just help, it sets the foundation for everything else. We tend to increase our perception of threat when we're sleep-deprived, and I think this is an incredibly important theme that will probably sort of run through this conversation because that sense of threat, that is not just psychological, that is very much physiological. So if your brain and your body are feeling on edge, then what happens? You amp up that sensitivity of the stress response, this physiological cascade which has evolved to help us to fight or flee or freeze in the face of danger.

8:08And for most of us, that means increasing adrenaline, increasing cortisol, increasing blood pressure, increasing the blood flow to the muscles, perhaps making us sweat a little bit more, mobilizing blood sugar, blood glucose, so that we're fired up for action. So that is an evolutionary response to being in an environment where we couldn't sleep well. So if you think about our hunter-gatherer ancestors, you know, if they were camped out next to a den of saber-toothed tigers, there was an evolutionary advantage in being in this increased state of fight or flight. They were much less likely to get eaten.

8:47And over hundreds of thousands of years, our brains have learned to associate sleep loss with potential danger. And so we are more on edge. So that helps to explain those emotional responses. also the physiological responses that over time our immune system becomes dysregulated more like to be exhausted almost because we're constantly ramping up our immune response ready to fight infection we also see that we're at increased risk of hypertension of inflammation these diseases which help to increase risks of heart disease of diabetes disrupted blood sugar i could go on But I think the other aspect is cognitive function.

9:32So we know that the brain does a huge amount of mental processing overnight. We are consolidating memories. We are pruning back information so that we can focus on what is most important. So sleep is really helping us to learn and innovate. So when we're sleep deprived, that sort of brain fog, that slowness to respond, slower reaction time, that can also have knock-on effects and increased risk of accidents and things like that. So we've got very acute effects and also more chronic long-term effects on health. If we want to make real progress with our health in 2026, we can't ignore sleep. It isn't just a nice-to-have.

10:14It shapes our stress levels, our immune system, our blood sugar, even our ability to think clearly. The good news is you don't need to start a complicated routine. In this next part of our conversation, Sophie shares some simple science back steps you can try to build a more solid sleep foundation. For our scientific co-founder, Professor Tim Spector, the quest for better brain health is deeply personal. Tim watched his mother live with dementia for years, and he's long known about his own genetic risks for high blood pressure. Recently, Tim underwent comprehensive brain testing, and despite his expertise, his scans revealed something startling.

10:51High exposure to microplastics. was a wake-up call that our environment and our biology are under constant pressure. This led Tim to double down on the nutrition principles that we've developed here at Zoe that protect cognitive longevity. And we've compiled those principles into a brand new guide called Eating for Better Brain Health. This isn't just generic advice. This is your brain-gut blueprint. Inside, we break down five core strategies like pivoting your protein to clear your vascular highways. We even include the kimchi kick breakfast recipe to lower your inflammatory response. As Tim says, for 40 years, we've been going down the wrong path, treating the brain as something different from the rest of the body.

11:34Stop leaving your brain health to chance. Learn exactly how to rewire how you think, starting with what's on your plate. Download the guide for free at zoe.com slash brain health. That's zoe.com slash brain health. Or click the link in the episode description. So let's keep it simple. Start first thing in the morning. Wake up at the same time as often as you can. So set your alarm for the same time each day. When you start to do that for a week or two, you'll find that you don't need the alarm anymore. But try and aim for consistent wake up time. Aim to get some natural light, ideally within the first hour after waking.

12:12That's going to kickstart your circadian rhythm for the day. Tell the clock that it's wake up time. and the advantage of doing that is that if you get this bright light in the morning it's going to banish the melatonin so you're going to feel more alert but automatically 15 or 16 hours later you're going to start to feel sleepy. Move your body during the day whichever way makes you feel happy but get physical be active. There was some recent research actually suggested that yoga was one of the best forms of exercise for sleep So it doesn't need to be super intensive. It just needs to feel good for you.

12:48Take some time out to relax during the day, particularly if you're a busy person that goes from A to B at 300 miles an hour. Just take 15 minutes for yourself, a moment to be and not do. And then as we come towards bedtime, try and have a consistent wind down time. I'm not bothered about whether you get into bed at exactly the right time, but try and have a consistent time where you start to switch off. So in that hour of wind down, get done what needs to be done for tomorrow, some form of relaxation, something to look forward to, whether it's a warm bath or reading a book or doing some breath work, listening to music, some intimacy with your partner, with your family.

13:31Social connection is often neglected in terms of its role in improving sleep. And then during sleep, you want darkness. Use an eye mask or blackout blinds. Try and sort of banish light from your sleep environment. And just let it come. Don't try too hard to sleep. That sounds brilliant. The one thing I haven't heard you mention I'm curious about is use of that smartphone. Because you said right at the beginning, that's the number one thing that's really changed everything and made this worse. In my book, That Wind Down Time, that's when I'd be switching off the phone. Ideally, the phone does not come with you into the bedroom.

14:09Buy a cheap alarm clock that has no smart functions. And this is something that actually can be really good for families. So parents will often say, you know, how do I separate my teenager from their phone? Well, if it's something that everybody does, it's just a norm. The phones don't go into the bedroom. That's not where they live. That just is a rule that you can make for yourselves. If I do all of these things, if I'm not in the insomnia, but I'm in that 50 to 60 % of people are not getting their best sleep, can it really transform my sleeping? All of those things might help a bit. I don't want to overdo the sleep hygiene piece because I also know there are some great sleepers out there who have pretty poor sort of sleep habits.

14:52They're all part of this picture of positive sleep health. I think if there was anything to add to that, it's just that I would love people to believe that sleep is important, but also to believe that they are good sleepers. A lot of what I do is help people build confidence. So if you do those habits, what happens is that you build confidence that you are going to sleep well. So that helps to ease the anxiety. If you're someone who has been anxious about sleep in the past, the danger of this advice is that it's too rigid and that if you haven't had 15 minutes of daylight within an hour of waking up, you start to get anxious.

15:33If your phone's accidentally gone into the bedroom, then you might have a terrible night's sleep. So these are guidelines. They are recommendations. They are not strict rules. There's one sleep rule many of us grew up with. Never eat cheese before bed. Supposedly, it guarantees bad dreams. I asked Sophie whether there's any real science behind this idea, or if it's just another sleep myth we can finally let go of. As you'll hear, the evidence is, well, pretty thin, and mainly linked to people whose bodies don't tolerate dairy well. So for most of us, there's no strong reason to fear a bit of evening cheese.

16:12It's nice to be able to finally put that particular sleep story to rest. so there was a paper that was published i think just a month or two ago on this and it was actually a survey so this was a canadian study and over a thousand students who got credit for taking part in the survey and they asked them about the foods they ate and whether the people thought they influence their sleep and their dreams and out of a thousand people i think only one percent suggested that dairy influenced their dreams. The study suggested that that population were more likely to be lactose intolerant. So of course, if you're eating something that really doesn't agree with you, it may well disrupt your sleep.

16:52So now you've had a good night's sleep, you wake up feeling more rested, and then comes a very familiar question. What should I have for breakfast? For many of you, that answer is a bowl of oats. But in 2025, oats became surprisingly controversial. Some people praised them as heart-healthy hero. Others worried they might send blood sugar through the roof. Dr. Sarah Berry and I unpacked the evidence. First, we looked at the big picture. What do long-term studies actually show about oats and heart health? There's some fantastic data that's come from what we call the epidemiological studies, which are studies in large populations, where they've followed people for a long period of time and looked at depending on whether people are oat eaters or not oat eaters, whether that affects their risk of disease.

17:40And in one such study where they followed more than 500 ,000 individuals over many years, they found that people who were oat eaters versus those who didn't eat any oats actually had lower rates of type 2 diabetes by about 15 % and lower all-course mortality, which basically means risk of dying. And that was by about 20%. Now, obviously, there's lots of other things that might explain some of this. People who eat oats tend to smoke less, et cetera, but you can actually adjust for that in the analysis. You can never fully disentangle it. So it's not the strongest evidence to pull on. But that gives us an idea that there's something going on there, that there's something about eating oats that might be beneficial for our health.

18:29And so the next thing we need to look at is clinical trials. And also, is there a mechanism? Is there some kind of rationale why we might be seeing this? And what we know is that oats contain a very special fiber called beta-glucam. And this fiber is well known to reduce circulating cholesterol levels. So to reduce total cholesterol, but also reduce LDL, which is our bad cholesterol that we know is linked to heart disease. And there's been lots of clinical trials that have been published showing that if you add oats to a meal or the beta-glucan to a meal, that you can significantly reduce people's cholesterol levels.

19:10It needs to be about a certain dose. So we know that you need to be having about three grams of the beta-glucan a day in order to lower your cholesterol. And so the FDA in the US and the EFSA, the European Food Standards Agency in the UK, actually have an approved health claim that beta-glucan, this fiber that's in oats, at three grams a day can reduce your cholesterol and hence is associated with improved heart health. And I think the evidence is quite consistent for that. So oats came out looking pretty good from a heart health perspective, especially because of that special fiber, beta-glucan, which can help lower cholesterol when you eat enough of it regularly.

19:53But what about the other concern, blood sugar spikes? To test this properly, Sarah and I turned ourselves into guinea pigs. We both ate a bowl of instant oats, the kind you might pop in the microwave in the morning, and we tracked what happened to our blood sugar in real time. I'm gonna scan mine and show you what I've got, Sarah. Here we go. Wow. Can you see that? So Jonathan's has just gone up to 10.7. I can't believe that. Well, I can believe it, but I'm quite surprised. And mine's gone up to 8.4. So Sarah, I just had 10.7 and my number when we scanned it 20 minutes ago was around six. What does any of that mean?

20:35What's going on? So what's happening is the carbohydrate from the oats is being processed and broken down into glucose molecules. And the glucose molecules are now passing through your bloodstream. And this is what we're detecting from the glucose monitor that you're wearing on your arm. So you're seeing this increase in circulating glucose from the carbohydrates that are in those oats. And this increases within five to 10 minutes after eating any carbohydrate-rich meals. Typically, it peaks around 30 minutes. So it'll be interesting to see what it looks like in about 10 or 15 minutes. And it seems to me that that number has shot through the roof in the last 20 minutes when I ate this instant oats.

21:20In fact, I have worn these before. I don't think I've managed to get above 10 with anything I eat in the last three or four years. I definitely did used to go above 10 before I started at Zoe. So that's a pretty impressive spike I've achieved, isn't it? Yeah, that's quite a big increase in blood sugar levels. Now, an increase in blood sugar after carbohydrate-rich meal is a normal physiological response. But once it starts to get really high, quite often it can impact how you're feeling in the moment. So it might be that you have a slight headache or you might feel that your heart is racing a little bit.

21:55Also, about two to four hours after having quite a big peak like that, you might get a dip in blood glucose. And we found from our own Zoe research that that dip can drive increased hunger, increased food intake. it can give you poor energy, poor alertness. What we also know is if you are eating every day, all of your meals to cause that kind of peak, that over a sustained period of time, we know that that's linked to some unfavorable long-term health effects, like an increased risk of obesity, type 2 diabetes, and cardiovascular disease. So I would not recommend based on that, you having instant porridge on its own with water for every meal of the day, absolutely.

22:35Or even every breakfast, right? No, because you're likely as well to just not feel great for the rest of the day because it sets you up on that kind of roller coaster where you're having the big peak, you're having this dip, it's driving you then to go and have a quick fix to get your blood sugar back up. You're then eating more at your next meal and you'll probably feel less energetic, less alert. So yeah, I wouldn't advise that. Now, Sarah, you didn't eat exactly the same thing as me, did you? You added all those other ingredients onto these instant oats. why is your number not the same as my number Sarah?

23:09So I added nut seeds dried berries and some nut butter and they contain extra fiber extra protein and extra fat and we know that fiber fat and protein impact the rate at which our stomach empties they impact also the rate at which blood glucose is then absorbed from the bloodstream and also some hormones like insulin which obviously also impact how we metabolize the blood sugar. So by adding and layering on this extra fat, protein, and fiber, it modulates how quickly we absorb the glucose. So it modulates this rise in blood sugar. And Sarah, I know what we have with our meal is one part, but also it's true that we don't all respond the same, right, as we eat these meals.

23:56And you already showed that my baseline blood sugar was higher than yours. So even with your pairing, Sarah, and the fact that your blood sugar control is better than mine, isn't it? I think when we've done these tests, it turns out that my blood sugar control is really quite poor. My memory is that yours is fairly good. Yeah, mine is a little bit better than yours, yes. And it's surprising actually, even though I paired it with the fiber, the fat and the protein that it's still gone up that high. And I remember the first time that I ever did this test with Zoe with my blood sugar sensor, this was the thing that blew my mind because I sort of thought like these oats, right?

24:36They're really healthy for you. And yet I was having this response, which was sort of as fast as when I just drank a sugary drink. and it seems to me that what you're seeing there Sarah is even when you've mixed in those other things that this instant oats is it feels like it's almost like you're having sugar with your yogurt what's going on there yeah and it's all to do with the magic of the food matrix that we often talk about here at Zoe which basically is the structure of the food so for example there was a clinical trial where they asked people to eat one day these steel cut oats another day the rolled oats, another day instant oats, and another day really heavily processed oats that are used often in breakfast cereals like Cheerios.

25:23And what they found, similar to what we've observed today, is that the less processed, the lower the blood sugar response. So the steel cut oats cause the lowest increase in blood sugar after eating. The rolled oats that we had yesterday called only a moderate increase, but as it became more processed up to the level of the oats that we had today, you got a bigger increase. And it's because of changing the structure, changing the rate at which the stomach empties it, the rate at which they're absorbed, that you see these differences. One of my biggest lessons from that experiment is that not all oats are created equal.

25:59The more processed they are, the bigger the blood sugar spikes we tend to see. A simple habit I'm taking into 2026 is to choose less processed oats, like steel cut or plain rolled oats with no added ingredients, and to dress them up with plants, fiber, healthy fats and protein to help smooth out those spikes. Repeated blood sugar spikes can contribute to chronic low-grade inflammation in the body. And inflammation is at the heart of many conditions, including arthritis. arthritis. So next, I turn to Dr. Tomiko Katsumoto, clinical associate professor at Stanford University, to help us understand the different types of arthritis and why joint pain is becoming so common.