If you had to do just one thing to improve your health, what would it be?
Our busy lives make it difficult to keep up healthy habits. And with so much conflicting advice out there, it’s tricky to separate fact from fiction.
Michael’s latest book, Just One Thing, explores these habits. It's seen him speak to singing scientists and eccentric icemen, healthy habit experts and evangelists. And of course, being Michael, he tried out every habit himself.
Michael discusses which healthy habits are most effective, which he's incorporated into his life, and how he makes them stick.
If you want to uncover the right foods for your body, head to joinzoe.com/podcast and get 10% off your personalized nutrition program.
Episode transcripts are available here.
Michael Mosley’s book is available to buy here.
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[00:00:00] Jonathan Wolf: Welcome to ZOE Science & Nutrition, where world-leading scientists explain how their research can improve your health.
If you had to do just one thing to improve your health, what would it be? It's a question that medical doctor, journalist, and presenter Michael Mosley set out to answer in his book, Just One Thing. From singing scientists to eccentric icemen, Michael spoke to healthy habit experts and evangelists to separate fact from fad.
And of course, being Michael, he tried every habit out himself.
What we wanted to know was having tried them all, which are the most effective, which has he incorporated into his life, and how does he make his new habits? Today Michael joins us alongside ZOE regular Tim Spector, to discuss his four key habits to improve our health.
Michael and Tim, thank you for joining me today. I feel surrounded by an amazing amount of knowledge on lifestyle and nutrition, and I'm really looking forward to this. We always start the podcast with a quickfire round of questions from our listeners, and the rules are very simple. You can say yes or no, or a maximum of a one sentence answer, but no more than that.
And I wanna have a little bit of fun this week because I think having Tim here with you, Michael, I know that Tim is a bit of a rebel. He doesn't really like to agree with anybody, and so I thought it would be quite fun to ask each of these questions and have Michael first, and then Tim afterwards, and see where that leads us. So this might be a horrible idea, but I thought I would give it a go and I'm far enough away that Tim can't hit me. So…
[00:01:58] Tim Spector: We can always edit it out if it ends in a blood bath, can't we?
[00:02:04] Jonathan Wolf: Alright. You both trained as medical doctors for the average person can lifestyle changes be as powerful as medicine for our health?
[00:02:14] Michael Mosley: Yes.
[00:02:15] Tim Spector: Yes.
[00:02:17] Jonathan Wolf: Easy. You see? All right. Can plants around us in the house or in the garden make us happier?
[00:02:24] Michael Mosley: I think they can make you feel happier. Yes,
[00:02:27] Tim Spector: Definitely nature makes you happier. Yes. We've evolved to be happy in nature.
[00:02:33] Jonathan Wolf: Is a cold shower really good for our health?
[00:02:36] Michael Mosley: Perhaps. I think the science is still a little bit out on that one.
[00:02:42] Tim Spector: I'd agree. I think it might vary enormously by individuals and it's something we really need to test.
[00:02:49] Jonathan Wolf: Can the way we breathe affect our mood?
[00:02:52] Michael Mosley: Yes.
[00:02:55] Tim Spector: I'd say perhaps.
[00:02:59] Jonathan Wolf: I'm glad I was looking for a little bit of disagreement and we'll talk a bit about this. I'm looking forward to talking about this one. And lastly, if we exercise regularly, will we start to enjoy it?
[00:03:11] Michael Mosley: No, not necessarily. At least.
[00:03:14] Tim Spector: I know Michael doesn't enjoy it, that's why he said no. But I think it's highly personalized, so some people will, and I think there's definitely some people who won't.
[00:03:24] Jonathan Wolf: Brilliant. Well, look, I think that's gonna, that sort of sets up the podcast beautifully. And so, you know, the idea we had, very lucky to have Michael and Tim on the podcast is that Michael's investigated a lot of sort of new and emerging health trends over the years. And one of the things that he's been really focused on recently has been this idea of sort of simple changes.
So something that's not too complicated that you could take on board that could actually have like a real impact on someone's health. And some of these ideas are quite surprising. Some are even really quite counterintuitive. So you know, why would dumping a load of freezing water on your head be any good for your body?
Right? That sounds sort of mad. Or why would running down the hill potentially be better for you, for your muscles than, you know, running up a hill? And so we thought it would be fun to run through a few of these and understand a little bit from Michael and also from Tim about their views on I guess these emerging new ideas.
And I thought the first one since we've, we've just sort of touched on it already, that would be fun to talk about is cold showers. And Michael, do you want to explain, I guess, what you've seen and your thoughts about it?
[00:04:34] Michael Mosley: Yeah, so cold showers, and also cold water swimming has become incredibly fashionable, though it has been around for a very, very long time. The Romans used to practice having warm dips followed by cold dips and things like that. So lots of enthusiasm for it. And as part of the sort of Just One Thing, I gave it a go and I have persisted with it, but a lot of hype around it as well.
Wim Hoff is a famous advocate of hanging around in your underpants in sort of subarctic temperatures or dipping himself in barrels of cold water. And for a series I recently made called How to Live to 101, I went to interview him in Holland and he did all these things with great gusto, but I think the science is not perhaps as firm as some of the advocates would say, but there is definitely something there and I'd love to see it explored more, but, in brief what I do these days is I go and have my warm shower, wash myself, and then I blast it to cold, and then I stay in there for about 40 seconds. I normally sing vigorously while I'm in the shower because that detracts from the cold? My wife also does it. She allows the water to stoically fall over her.
I spoke to a guy called Mike Tipton, who is a professor at Portsmouth University and who studied the effects of cold water immersion, and he advised me that what you need to do is stay there long enough until you stop gasping because your first reaction of cold water immersion is, and then you have to slow it down.
And when your heart rate and well, basically when you stop gasping, that probably means you've been there long enough.
[00:06:14] Jonathan Wolf: And you've been doing this for quite a long time. Then this is a one thing that has stuck.
[00:06:19] Michael Mosley: It has stuck, but it's more, to be honest, in the summer months than in the winter months. The winter is too cold and I find it a bit brutal and I sort of have swings and roundabouts. So the main two areas where cold showers do seem to have an impact, and particularly cold water, swimming has an impact, is potentially on the immune system.
And secondly, on your mental state, if you like, on happiness, on how you feel. So the data around the immune system is variable. That's what I could say. The best study so far was probably a Dutch study where they recruited 3,000 people and randomly allocated them to either having a 30 second cold shower, 90 a second cold shower, or just sticking to a warm shower and they had to do that for a couple of months. And then over the subsequent winter, they looked at how many people took time off and the group who had had the cold showers, they took significantly less time off. Now it didn't seem to matter whether it was 30 seconds or 90 seconds, they got the same sort of, you know, effect.
So that's not a truly wonderful study, but it is at least indicative. What do you think?
[00:07:32] Tim Spector: Yeah, I mean, I haven't looked recently, but when I did a few years ago, a lot of these are case reports of people maybe with quite severe depression that do get benefits from this. I think the immune studies are always hard and there are confounders about, you know, things like time off, but I believe there's probably a strong placebo effect of these showers, which we shouldn't ignore, that is highly effective and I started doing this just to see what it was like and what could I put up with it.
And interestingly it's the opposite. In the summer, my cold water system goes much colder than it does in winter where it's heated up by the hot water. So I get more of a differential in summer. So I find in winter it's not much different really cause I've got a really old heating system, but I did find it was sort of invigorating.
So whether that boost psychologically helps you and then, you know, aided by a bit of placebo in the idea that people like Michael are saying it's good for you and Wim Hoff but I think it's gonna be highly personal and I think we do know from temperature regulation in the skin and things that there's huge genetic variations in how people respond to cold.
And we did a lot of these twin studies. Putting twins’ hands in ice buckets and things and found that this perception of, you know, that cold pain varies enormously between people and, I think this probably means that these treatments need to be quite personalized and 30 second cold showers for some people might be absolute torture for other people it's nothing at all.
So I think we need to refine this much more. It's definitely worth doing bigger population studies and I think this is one of the things we'd love to do in the ZOE Health Study is get people taking cold showers. And I like the idea that you may only need 30 seconds, because I think most people could get away with that.
[00:09:27] Michael Mosley: Absolutely and beyond that, I love the idea that it's not necessary to do more. That more is not better. What Professor Mike Tipton said to me is he thought it could be that what you're doing is you get a stress response. You get stressed when you have a cold shower without a doubt, you do adapt. It takes about six sessions before you adapt and it becomes for most people more acceptable.
But he said that it seems to be that you get a cross response. So that he did a study where they got people to do cold showers and then it turned out they were better adapted to, you know, surviving at altitude. Being, you know, responding to one thing was better than another thing, so he thinks there may be something going on there.
He also stressed some of the dangers. And indeed, I was involved in a rather peculiar incident a couple of years ago. I was swimming in the sea with my wife Claire, off the coast of Cornwall. It was May, it was pretty cold. And we'd just gone out to a boat and were swimming back and I thought, well, I'm going to beat Claire to the shore and the next thing I know, I'm in casualty. And apparently what had happened is I'd swam back to the shore. Claire swam as shore as well, and she said, how are you Michael? I'm looking really vacant, and I clearly have no idea who she is or who I am or where I am. Though I kept on repeating, I have a wife I have four children.
And so I ended up in casualty and got a thorough examination, couldn't find anything, and then the consultant rolled up and he said, you have something called transient global amnesia. Which is relatively rare, but it's brought on by swimming in cold water. So my memory banks have been entirely wiped for about two, three hours and then it gradually came back.
[00:11:03] Jonathan Wolf: It's like a plot for a really bad sort of Spanish drama series if it only is supposed to last for three months and not three hours. So I think that's amazing this actually happened.
[00:11:14] Tim Spector: It's a great excuse. Every morning you have a cold shower. You say, oh, I've got global amnesia. I can't remember, was I really supposed to do this podcast?
[00:11:22] Michael Mosley: Well, exactly. Was I supposed to be here or not? the other thing is apparently, it's caused by a sort of transient change in your blood pressure and the blood flow to the brain. It can also be triggered by sex the neurologist told me. So that is also, you know, you have sex and then you completely forget who you are, where you are, and who you're with.
That again is kind of rare. But, the serious point here is, don't go cold water swimming by yourself, particularly if you're not used to it, because there are risks. You know, particularly if you're unfit, you could have a heart attack, drop dead. You could have your memory wiped. Who knows? So try and do this sort of thing with someone else.
[00:11:59] Jonathan Wolf: And it's interesting, II have a personal story here. I have a very good friend who will, who will know who he is when I mentioned this, who started working for a company that's based in Finland. So way off in the, you know, the icy waste. And he went there for his first sort of, company offsite about three weeks ago, and the entire company went and had a big sauna, get incredibly hot on an island. And then apparently they walked out onto the ice and they've dug a big hole and they expect everybody to just jump in. And apparently everybody who was Finnish was just, they didn't only just jump in the water, he said they sort of sat in the water having a pleasant conversation and my friend thought about this quite hard and then said, no, I'm not going to do this.
So ,clearly there's something cultural here also isn't there about thinking that this is normal.
[00:12:46] Michael Mosley: Or thinking this is insanely dangerous.
[00:12:49] Jonathan Wolf: or insanely dangerous. So, what's our view is this making everybody in Finland live longer? Tim?
[00:12:55] Tim Spector: Well, and they always claimed that saunas were helping people and I think when they did some studies, they found there as many people had heart attacks as, you know, maybe lived longer. So it's probably highly personalized, but I think the point is that if you're doing something regularly, and small stresses to your body generally, that's a good thing.
So as a general principle, a lot of the things I think Michael talks about are these small little mini stresses. And this, whole concept of hormesis, a little bit of what hurts you, helps you, a little bit of poison is good for you.
[00:13:30] Jonathan Wolf: And can you explain that for a minute? Just because I think the story sounds great. I think the thing that I'm struggling with is, why is doing something that is unpleasant, like a cold shower, going to help? I think we understand with exercise that we understand that it's, you know, you're gonna build your muscles, all of these things.
But the cold shower I'm struggling with. Why might that be good for us?
[00:13:52] Michael Mosley: I mean, the idea is, as I said, that you build resistance to this particular stressor, and therefore, potentially you are developing resistance to other stressors as well at the same time. There's also a thing called cold shock protein. When you're in hot water, there's heat shock protein, and these things are associated with repair.
As you're saying, with exercise, you damage yourself, you rip muscle, and it's actually the process of repair, which seems to be good for you. When you do something like fasting then again, one of the arguments is the reason why it has been, at least in animals and in some human studies, been shown to prolong life is because it is stressful and stress evokes response from your body that, as Tim said, that which does not kill you, makes you stronger.
[00:14:39] Tim Spector: It's all about getting the dose right. If you did that, it actually stimulates the whole system a little too much, and it knocks you off.
[00:14:47] Michael Mosley: Yeah, a little spot of arsenic peps you up.
[00:14:50] Tim Spector: Never hurt anybody. That's right.
[00:14:52] Jonathan Wolf: Please don't try this at home is I think what we add immediately on the podcast. Well, and it sounds like just to summarize, this is like, it's interesting, the scientific data isn't really strong, is what I'm hearing. So this is one of like many of these areas where there's something interesting, there probably hasn't been enough experiments done at enough scale to really show, you know, whether it's compelling.
And I think also, Tim, you're saying in your suspicion is there's a lot of personalization in the sense that this might really work for some people and not for others.
[00:15:22] Tim Spector: Yeah, absolutely. And the dose might vary for different people as well. As our immune system is highly variable and personalized, so we might need different stresses and things. So this is very much an overarching theory that it's very hard to do these experiments in humans and, you know, stressing a worm and making it live longer isn't necessarily the same in humans.
But generally, certainly the age research community is coming round to these ideas that these things are important and it's all about, you know, how our body senses these, stresses and these outside influences, whether it's diet or from the outside world and then sends other repair mechanisms to sort of work.
So, it's definitely more of a hypothesis at the moment than actual hard fact, but it does seem to explain a lot of these anecdotal events.
[00:16:12] Michael Mosley: I've actually been making a series for the BBC called How to Live to 101, which took me around the planet and I was looking at some really interesting stuff in Israel where they induce a relative hypoxia. So what they do is they put you into this bariatric chamber, which basically, you know, can raise and lower air pressure, and then you have to inhale oxygen.
They whack the pressure up and then they drop it. And so your body perceives that you're kind of short on oxygen, so you think that's a really, really bad thing. Your brain's gonna go, Ooh, I haven’t got any oxygen. But actually what they've shown is that doing this leads to the production of BDNF, brain derived neurotrophic factor in the brain, the release of more of this stuff.
And they've got some pretty compelling evidence now indicating that it's helpful for things like stroke, possibly for long covid and they're doing big numbers. I mean, this was a large institute, lots of people. Proper science going on, and you would not have bet money that inducing hypoxia was a good thing for your brain.
And, as I said, that's some of the, it's a different way of stressing your system. Again, not something you wanna try at home.
[00:17:20] Tim Spector: Well, that also links in with some of these breathing exercises that are coming along where they're actually promoting increasing the co2, carbon dioxide in your blood, and that seems to be another stress that is helpful and actually helps you absorb more oxygen. So some of these things seem counterintuitive, but, it's all on this general theme. It's a stress.
[00:17:46] Jonathan Wolf: Well, that's actually a brilliant transition because the next one that I wanted to talk about was taking deep breaths because that also seems like a bit ridiculous as something that's going to make a difference to your health. It's something that I might sometimes say to my wife and my wife might sometimes say to me, but that's mainly because I was really annoying.
Not because I think it's going to affect your health, but actually I think, Michael, you had some really interesting stuff about this idea that actually the way we breathe might have some impact on her health and I'd love you to sort of share what you discovered.
[00:18:18] Michael Mosley: Sure. So when I was looking into Just One Thing, I'd been sort of aware of it because, my sister teaches mindfulness and kind of breathing is part of that, at least being aware of your breath but not actually consciously controlling it. And then I came across some really interesting research showing that deep belly breathing, so the idea is it's not just deep breathing or slow breathing, it is belly breathing.
You're trying to, you put your hand on your gut and you should feel it kind of go up and down rather than breathing. You do really slow, deep breaths and one technique is called 4-2-4. There are quite a few other ones, but essentially you breathe in through your nose to count of four, hold it for two, and then you breathe out your mouth to count of four. And when you do that for even a minute or so, what happens is your heart rate will start to drop and you'll kind of begin to feel calmer. And I was interviewing an expert and he said one of the reasons is, as Tim was sort of alluding to, you’re altering the carbon dioxide levels in your brain, this switches on part of your system known as the parasympathetic system, which is releasing noradrenaline.
So everything kind of slows down. And, all the great religions have sort of advocated some form of breathing exercise. It's been particularly popular with people who are doing yoga and things like that. They've always advocated different forms of deep breathing. But now we’re kind of recognizing that something really to it, and when we did a podcast on, it was overwhelmingly the most popular podcast we had ever done.
And that was just about breathing, which shows you, I guess there are a lot of people out there who experience anxiety and sleeplessness because I was essentially saying this is a really good way of coping with an anxiety attack or if you're feeling anxious. But also it's something I do at three in the morning when I'm waking, you know, and lots of restless thoughts.
I just practice this breathing and it's surprisingly powerful.
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[00:20:17] Jonathan Wolf: That's really interesting. I was actually, because I already, I thought that I remember that I was taught breathing techniques in my early twenties. I was diagnosed, with a lot of food intolerances as as quite a few people listening to this podcast know, which sort of started my 25 year journey of ZOE, and when I went to see all the doctors, you know, you don't have cancer, et cetera. That's good.
They didn't even know what the microbiome was back then, Michael. So that definitely didn't come into the conversation and the conclusion was probably, you're really anxious and this is like a big part of this. And so I got sent to see somebody who taught me about breathing. With some sort of feedback mechanism where you could sort of see something on the screen going up and down.
And I think what I took away was you really could reduce your level of tension from breathing and that I was terrible at ever remembering to do it at any points when I really needed to use it. So I think like many of these things, there's this sort of huge gap between like this healthy habit that you should do and then actually managing to do it. is that a common challenge or is this just, am I the only person?
[00:21:24] Michael Mosley: Oh, absolutely. But the thing is you need to practice. You need to practice, practice so that when you are having an anxiety attack, a panic attack. When you’re feeling terrible you actually do it because your natural inclination is to hyperventilate that when you're feeling anxious, you're aah, and then you go, and then that makes you feel much, much worse and you forget everything you've ever heard on, some podcast or other, and you just go, ooh.
[00:21:47] Jonathan Wolf: And that is having the reverse effect, is it so that it's the opposite of the deep breathing that you're describing that's actually making you more anxious through this?
[00:21:54] Michael Mosley: Yeah, you've gotta kind of practice it. And as I said, you've gotta find a technique that works for you. Another very simple one is four six. So you breathe in for a count of four and then out to a count of six. And actually the exhale, some people say the exhale should be longer than the inhale, but you find something you're comfortable with, you practice it, you take a few minutes out the day to do it, you gotta find a trigger. So I find, for example, with things like doing press-ups and squats, I do them first in the morning. I do them with my wife, Claire. Two reasons. One is we encourage each other to do these exercises. Otherwise, you know, you probably wouldn't because the moment passes.
And the other is I'm using the fact I've gotta get outta bed as my trigger to do them.
[00:22:36] Tim Spector: If you want to try and breathe like Michael, you can go on the ZOE Health Study app. And at the moment we're running a study where we're trying to encourage people to do these habits and one of them was learning to breathe better and through just a five minute exercise a day. I think, as you said, there are many different ways of doing this, Michael, aren't there?
So, but I think the one we've had was 3, 4, 5. So breathe in for three, hold it for four, then breathe out for five, which is this idea that actually you slightly, you know, exhaling more and making yourself slightly hypoxic as a way of clearing out the system.
[00:23:13] Jonathan Wolf: And hypoxic, Tim? Hypoxic means?
[00:23:16] Tim Spector: Hypoxic means you're getting low in oxygen, relatively. So we always thought that was a bad thing. As Michael says, you know, there are lots of treatments that seem to improve you by doing it, and again, it's this sort of stress and studies have shown that if you do sort of get rid of oxygen, which means by definition building up carbon dioxide in your body, more than you would normally do this can have positive benefits and allows you, there's some evidence in athletes that if you build up co2 then you, it allows you to use the oxygen better and actually your body becomes slightly more efficient.
So this is all done on small numbers and we haven't really sort of worked out how this works at the population level. That's why we sort of want more people to do these studies and say, well, Who does it work for? You know, is it same for men and women? Is it different at different ages? But the app that we developed and just still developing, it's still an evolving thing helps people log every day, how they feel and whether it's helping them or not.
And, I think, you know, we'll hopefully come back and we can discuss some of these results. But anyone who wants to go, they can still go on and download that app and have a go. And it's just another thing to think about in our busy lives. Just say, am I actually breathing properly? Unless I've got a cold, why, why am I breathing through my mouth?
You know? Think about it.
[00:24:44] Michael Mosley: Absolutely. Interestingly, I've actually just been doing a podcast where we are looking at mouth breathers and as you say if you breathe through your mouth, it kind of dried out your mouth. It makes you more prone to infections in the mouth, dental caries and things like that. And obviously you kinda snore more.
But what was really interesting as I was talking to a Norwegian scientist and he said, when you breathe through your nose, he discovered that breathing through your nose releases nitric oxide in the nose, and this kills the bugs in the nose. But the nitric oxide also travels through your blood to your lungs and that increases oxygenation, particularly in the upper lobes of the lung. So, we don't entirely know what that means, but it's kind of interesting that there is a significant difference between being a mouth breather and a nose breather from that point of view. And again, it's something that the yogics have been keen on for a while, is yogics a word?
I don't know. But yeah, it makes you kind of think even a simple thing like breathing can have quite a profound effect on your sort of mental and physical state.
[00:25:45] Tim Spector: My grandfather in Australia when I was six, took me out every night into the garden. He was in the Australian army and used to get me and my brother to do deep breathing exercises. We were in our pajamas before going to bed, and we thought he was completely mad, but of course he was way ahead of his time then.
[00:26:06] Jonathan Wolf: That's brilliant. Well, I think going into the garden is a brilliant transition to the next simple thing, and I would love to talk about house plants and the benefits off gardening more widely. I'm quite a keen gardener myself, although I do find that ZOE has slightly restricted the amount of gardening that I might want to do.
Never mind having broken two toes, but I've never really thought that it had any like real health benefits. But I believe, Michael, that there might be some suggestion that it does?
[00:26:38] Michael Mosley: Absolutely. I mean, I think I and Tim and you and everybody would agree that spending time in green spaces is really good for you. And there's also research showing that spending time in blue spaces, which is down by the sea or by a river is also kind of good for you. We were looking specifically at house plants.
Now I was kind of critical, or at least a little bit cynical about this. A couple of years ago when I was making a series called Trust Me, I'm a Doctor, we did this experiment, with the University of Lancaster, which I thought will never, never work. But the results were really interesting. What we did is we were looking at the health of people living near a busy road and we've got them to wear pollution monitors, and they had quite high levels of some of the nastier pollutants like, the small particle stuff.
And when we examine their house. Indeed, lots of these small particles were in the house, and so what the scientist said is we are in front of some of the houses. We're gonna just put some plants are basically some small trees, silver birch in tubs and see what happens. And I thought a few silver birch trees are gonna make no difference whatsoever, but surprisingly enough, yes, the houses in where the silver birch is were in front, the levels of pollution in the houses was lower, and that seemed to be because the silver birch's were capturing the pollution in the leaves. And then when it rained, they were sort of flushed off and they went down the sewer.
So we thought house plants. Now, NASA had done an experiment in the late eighties where they had in an enclosed space, they had increased levels of what are called volatile organic chemicals. These are things like, you know, when you have air freshener these things, you know, they produce some quite nasty stuff like benzene, which is not terribly good for you. Indoor pollution. So what they've done is they've spread some of this stuff around, put some house plants in an enclosed space.
And indeed the house plants had reduced levels of benzene and also, you know, basically hydrated the chamber more. But people said, well, that's an enclosed space, so, you know, what can you expect. But, there was another group in Australia who did it in open offices, and again, the introduction of house plants had quite a big impact on these volatile organic compounds.
And plus, you know, people kind of liked having them around. And indeed what they demonstrated is, when you take the plants away, people really miss them. You need quite a few, ideally, in a sort of small office, I dunno how big your office is, but if you had five or six of them in there, that could actually make a difference both to the quality of the air, your breathing, how hydrated it is, possibly, but not very much to carbon dioxide, but again, which I, you know, never underestimated the power of the placebo, that you just kind of like having a living thing there.
And as long as you look after it, you'll feel a sort of a love for this plant as well.
[00:29:21] Tim Spector: There are quite a few epidemiology studies about depression and that being lower or protected by people who live in the country rather than urban areas and having gardening as a hobby. So actually gardening as a hobby has come out of a number of surveys as being protective for your mental health.
And what's also interesting is we looked in the twins and obviously we found that gut health on average better in people in rural areas than people in cities. So this is things like gut diversity and generally having more species and assuming a better immune function. And that was also associated with lower depression levels.
So it could be that people are out, but it's not, rather than just the plants themselves is actually people touching nature. Getting those microbes from the soil and having a better exposure to the general healthy microbiome around us, that is healthy. And that's one reason. Some cultures actually have school trips, like Japan to go and hug trees and go into the forests as a regular part of their activities.
Whereas, you know, in England it would just be in a concrete playground. But, you know, they really appreciate the concept of walking in nature as a regular event for their health.
[00:30:43] Jonathan Wolf: I love this idea. I normally have a great big plant right behind me, but since it's the winter in the Northern Hemisphere at the moment, I have it moved over right by the window because it's pretty miserable at this point where the sun is just starting to come back up so I can sort of shift it back into the darker end of the room.
[00:31:01] Michael Mosley: Absolutely, and you can also grow herbs. And Tim, I'm sure very enthusiastic about herbs. Rosemary is a brilliant herb to grow and smells fantastic. You can grow indoors, outdoors. It can be part of your five a day, ten a day. herbs and spices are particularly, herbs are sort of ignored as part of that thing, but, I love adding all sorts of strange and wonderful herbs to the food I eat. It varies it, but it is a contributor to your kind of gut health.
[00:31:28] Jonathan Wolf: Wonderful. Well, we've added the house plants to our life now. I feel that was fun and easy. Now let's talk about something that everyone knows they should do. But most people are not quite so excited about it. Let's talk about exercise and I think this idea we started with actually, which is whether or not you might enjoy it, was interesting.
But also the sort of exercise that might make sense. And, you know, Michael, I think this is something you've sort of explored a lot through your career. What’s your one thing on exercise?
[00:31:57] Michael Mosley: That it's a brilliant thing to do. That you need to do varied, Essentially, there are three types of excise you need to prioritize. Aerobic, exercise. Running, walking, swimming, cycling. Then there is resistance excise when a lot of people forget about or don't wanna do, which is press up, squats, lifting weights.
And the third one is balance. Because balance is an incredibly important part of, you know, being healthy and growing old and it falls off pretty fast. So you need to do all three, but some people are more enthusiastic about it than others. So I'm actually okay about doing the press up and squats, but I am not so crazy about the running.
And indeed, I took part in an experiment a while ago where I got together with some enthusiastic runners, and this was at the University of Nottingham in England, and we were actually measuring something called endocannabinoids. Have you come across them before?
[00:32:49] Jonathan Wolf: That sounds very complicated.
[00:32:51] Michael Mosley: They're essentially a cannabis like substance, and they are produced by your body in response to a variety of things, including, singing, which we touched on briefly, but also exercise. The thing is that some people get a big hit of them and some of us don't. So in this case, what happened is they, took some blood samples before we went for a run.
I was with, as I said, enthusiastic runners came back, measured our endocannabinoid levels. Mine had not shifted an iota. If anything, they'd probably gone down. Whereas the other three, they had shot up. They basically, they had such a good time, and one of them interestingly suffers from quite serious depression, and you could see the lift in her mood.
And then over the course of about six hours, as the endocannabinoid levels dropped, you could also see that she was becoming more withdrawn and she now runs ultramarathons as her way of self-medicating.
[00:33:49] Tim Spector: Yeah, well about 10 years ago we did do a twin study, several thousand twins, and asked them about exercise participation. And found that there was a clear genetic basis, not only on sort of, you know, how regularly they went to the gym or how regularly that they went for a run or walks that would support the idea that there everyone has slightly different thresholds, if you like, that's genetically hardwired.
Doesn't mean they can't exercise, but their preference would tend to be similar in the identical twins compared to the non-identical twins. So it suggests there is some genetic threshold, but clearly, you know, if you have to run, you'll run. You know, if there's a sabertooth tiger about to maul you, you'll run.
But I think getting that pleasure from it. It could be that some people get more pleasure from lifting weights, as you said. Others get it from running, others will get it from other forms of stress or relaxation. And in a way that gives our tribe this sort of diversity and greater survival.
So we're not all like lemmings. I mean just, you know, as soon as everything happens, we all go off and run a marathon, you know, that would be a bit weird.
[00:35:00] Michael Mosley: Burn off all those calories. Yes. And then starved to death a week later. Yeah.
[00:35:04] Tim Spector: But, they think our ancestors generally were doing brisk walking, rather than running. And suddenly when I was with the Hadza tribe in Tanzania, who are hunter gatherers, they just walked at an incredibly fast pace, which I couldn't keep up with.
And they could do that for very long periods of time.
[00:35:21] Jonathan Wolf: And I’ve often heard it described as getting endorphins from exercise. Is this just sort of like people not really understanding the science and is your cannabis related substance that I can't pronounce is that the same thing or is that something completely different?
[00:35:37] Michael Mosley: It's the same in the sense that it's a naturally produced euphoric, if you like, but there was a while where everything was endorphins. But as I said, now people are kind of looking at other things as well. So I think endocannabinoids is a sort of a sexy new kid on the block, although it's about 10 years since they discovered it.
And indeed the reason they went looking for it is precisely because they were aware with the endorphins that this mimicked, or at least if you take heroin or morphine, this was just mimicking something that we naturally have. So they thought with cannabis, cannabis kind of gives you a high, it makes you feel good, it makes you feel euphoric.
Presumably there must be something in your body which does the same thing. And that's how they came across endocannabinoid receptors. And then they started researching this thing. So also some suggestion that if you respond in that way, you get a big surge. That also gives you the munchies. Because I'm not a big cannabis consumer, but I am told that it can induce the munchies.
So for some people, when they go for a run, they want to eat a lot afterwards. Other people, not so much so.
[00:36:40] Jonathan Wolf: I think the idea that it's very personal, that's been measured I find very reassuring because I do exercise regularly because I'm convinced about the health benefits and I've never reached that point that I know lots of my friends who just say, oh, I've got this massive high while I'm in the gym doing it.
I always feel really good afterwards and I'm not sure how much of that is from any chemical benefit or how much of it is just knowing that I've finished, I've done it and I feel good that I've done this good thing, but I don't get the sort of buzz through the exercise, which I know some people talk about, particularly around things like running and, and all the rest of it.
And I've always like, it seems really unfair. It seems it would be much easier to do the exercise if you were actually getting pleasure from it. I mean, no one ever complains, oh, eating cake is really hard. You know, your body's giving you these great positive pleasure feedback, even though your brain is thinking this is probably not very good for me.
So it's very interesting they've actually been able to measure this and seen the, I guess you know, the story often of the ZOE Podcast, that there's this very personalized differences and that's starting to be something that you can see really, you know, in the chemistry. It's not just people, you know, pretending that they can't feel it.
[00:37:55] Tim Spector: Well, it's, it's often in the brain, Jonathan. it's often in the, they do these functional MRI scans and you, because we don't know all the chemicals. Michael's talking about some of the ones that are easy to measure. There's probably many that we can't get to at the moment that, we'll know in 20 years time, but they can measure on an MRI scan, which is like a brain scan where bits of your brain light up when they're highly active and they've done these studies in runners, non-runners, and, it's the pleasure centers basically light up.
And that seems to be the way we can measure this. And there's definitely variety in that. And I think one of the big challenges in sort of public health is how do you get people who say, I really don't like exercise. I've never liked it. I hated it at school. Doesn't make me feel good. I just feel bad afterwards.
How do you get them to exercise? And I think that's, Michael will agree that's a challenge.
[00:38:53] Michael Mosley: Absolutely, and they are the majority, unfortunately. The other thing we know is that when you do surveys of people, they say, yeah, of course I do 150 minutes. But when you actually fit them with accelerometers and things like that, you find they're just lying. And the number of people who hit the guidelines is in some cases, less than 10%.
So that is the challenge for our time. How do you make it pleasurable and you can make it more pleasurable by doing it with a friend. You're more likely to persist with it if you've got a friend running with you, if you've got a friend down the gym. The only reason people really employ personal trainers is because a personal trainer is gonna dig them outta bed and make them go for the run, and there is some companionship in that.
So it's how do you manage that? Just telling people that excise is good for them is not actually gonna make them do exercise when the alternative is sitting on the sofa eating eclairs and watching the tv, which is, which is fun for most people, although the long term, extremely bad for them. So just exhortation alone ain't gonna do it.
And so I'm a kind of great believer, you kind of gotta build it into your life. I live at the top of a steep hill and so I always cycle to the station. It's just over a mile. And I say to my wife, under no circumstances, pick me up. Even if I ring you up and ask you to come and collect me, say no. Because that will force me to go up the hill.
And then I put in little bursts of hit while I'm going up and arrived sweaty and hugely resentful, but at least I've done it.
[00:40:14] Jonathan Wolf: That's brilliant. So do exercise with a friend, you know, then your personal trainer is a way of also creating that. Build it into your life. Any other tips that you've picked up? because I think we all know how important exercise is for your health. Any other little tricks that you want to share?
[00:40:33] Michael Mosley: I think regularity as well. Find something that can fit into your life. because don't go say I'm gonna run a marathon because you probably never will. As I was saying about the press ups and the squats, I do them first in the morning because I know if I don't do them then I never will. And so expecting to go down the gym every evening at 6:00 PM is probably unrealistic for most people because it's not gonna fit into your life.
So ideally, have something which is triggered by something and which is more likely to be something you'll actually stick to rather than something you'll do. I know a lot of people who have run marathons and who never ran them again. It was so awful. They, they ticked it off their list, but it wasn't, you know, that isn't gonna set you up for the rest of your life.
That's kind of a one-off event. Great fun, very stimulating, lots of people shouting and cheering. But find something, just something and even better if you find something you actually enjoy. Whether it's playing football, whether it is you know, fencing, whether it is. Going and just going on a treadmill is miserable for most people.
And that's why they go down, they run on a treadmill and after they've done that for a couple of weeks, they go, oh no treadmill, no. Not gonna do that ever again. So, there are very, very few people who think that running on treadmills is fun. I dunno if Tim is one of them, but I'm certainly not one of them.
[00:41:48] Tim Spector: No, it is, soul destroying. But, but I think it's little things like, you know, you put the tea on or you're waiting for it to brew, or you got five minutes, you know, that's the time where you can just do some exercise or squats or, and you know, and I remember there are people like, Rangan Chatterjee have got little programs to get people clues that things you do in your life that you can just build in every day.
So a small amount every day is often much better than some big splurge at the gym every, every two weeks. And then you go and, you know, have a burger afterwards to celebrate.
[00:42:22] Michael Mosley: I was gonna say, there are things like you get told you should put your trainers down by the front door so you see them. But to be honest, I see the trainers by the front door and I just chuck 'em in the cupboard. I don't go, oh, I must put the trainers on and go for a run.
[00:42:34] Tim Spector: I found for me what works is getting straight outta bed and doing some exercise. I found, if I wait and I say, okay, I'll just read the news on my phone. I never go. It's only when your brain is too fuddled to stop you doing it do you actually get up and do that exercise and go down maybe and do your stretching, your sit ups and whatever.
If you delay it, you're lost. That inner brain that says, oh, it's nice and comfy here, Tim, you don't have to get up anymore will always win. So it’s all about making it effortless. So you either, you know, routine or effortless, they're the key things.
[00:43:14] Michael Mosley: One of the other interesting and odd things I came across when I was writing Just One Thing is the benefits of walking downstairs or indeed running down the hill, which I thought was odd. It's known as eccentric exercise or eccentric exercise. Have you come across this? There's a group in Australia and they did a sort of wonderful study where they got a group of overweight people and they asked them to basically either walk up or down, randomly allocated them to walking up or down a 10 story building, and one group had to take the lift at the top.
And then walked down. The other group, they walked up the 10 flights and then they took the lift down. And they had to do this twice a week for I think it was about eight weeks. And what was really surprising was the group who were walking down the stairs got the most benefit in terms of impact on their blood sugar levels, blood pressure. They burnt a few more calories, and also it was better for their bone density.
So the reality seems to be that walking down is in and of itself quite a serious form of exercise. And so I thought that was kind of just kind of wonderful and weird. And one of the lessons you draw from it is when you're doing the press up and the squat, what you want to do is really slow down the dissent.
That actually a lot of the benefit comes from when you're going down, not from when you're going up.
[00:44:34] Tim Spector: Yeah, I've noticed that when I’m doing mountain walks with some keen Alpine friends, the next day it's all my you know, those eccentric sort of muscles that absolutely kill me, not the, quads or, you know, the usual ones in the front. So it's all the back and the buttocks that really hurt. But, some people can't of course, I used to be a rheumatologist and early arthritis patients all complain that the first sign of arthritis is walking downhill. Cause it definitely puts more strain on the knee than walking uphill, which people find very strange and they say, well it can't be my arthritis because I'm fine when I go uphill.
But the first sign of usually knee arthritis is pain walking down down the stairs.
[00:45:17] Michael Mosley: I've also recently been looking at the benefits of walking or indeed running backwards. That's, a wonderful piece of research. I was talking to a researcher whose been doing it for 20 years, so I said, why, why on earth would you wanna do that? And she said, basically it was just an area which hadn't been explored by anybody else.
And, so, you know, you publish in the areas no one else was gonna compete with you. But she said, you know, footballers often train running backwards and supposed to be good for balance and also for back pain.
[00:45:44] Jonathan Wolf: Again, maybe one to think about before you try it home. Well, Michael and Tim, thank you so much. I think we could keep talking about this for hours, but I think we're unfortunately gonna have to call time. I'm gonna do what we always try and do here, which is a sort of a quick summary of what we've covered.
And please correct me if I’ve got everything wrong. We started off talking about some of the best simple things that Michael discovered through work for his book and podcast. I think we started with cold showers. Which amazingly might really have some health benefit. My takeaway is the verdict is out, but definitely worth further investigation, and that if you go outdoor swimming, you don't want to do it on your own because you might suddenly forget who you are and who you're married to.
We then talked about house plants and gardening, and I think the verdict was pretty compelling there. There really is benefit to both of these things. And I also took away the tip that, you know, if you're not so good as greenfingered, then you can't kill rosemary. It smells great and you'll be able to eat it.
So there's a sort of all round win there. Then we talked about deep breathing, and I think, again, surprisingly, sort of strong evidence is gonna have a very direct impact on your anxiety, how your brain is working. Again, not as much scientific investigation as you might hope. And I think another thing that might be very interesting,Tim, for sort of further investigation at large scale.
And I took away that, mouth breathing is bad, which is bad because I am a mouth breather I'm told when I go to sleep. And I'm not sure how to fix what you do when you are asleep. So we are probably a whole podcast on how to address this. And then I think at the end we taught quite a lot about exercise, which is obviously a big thing and within which there are many simple things.
We learnt this new word endocannabinoids, which basically means I get to make my own cannabis. Some of us have it, some of us don't, but everyone should be doing more exercise. And I think we had a few brilliant suggestions from just brisk walking and eccentric walking, which isn't walking in a funny pace apparently, but it's going downhill being better than uphill. I love the idea that going downstairs is better than upstairs. That definitely doesn't sound right.
And above all, build this into your life. So have some pattern, whether it's regular, doing it with a friend, finding something you enjoy so that this is repeatable rather than just something you do for a little while and then you drop.
[00:48:13] Michael Mosley: Very good summary. Yep. I'm with you all the way apart from the endocannabinoids, we all produce endocannabinoids. It's just some people appear to produce them with exercise and other people don't. They have multiple effects throughout the body and we're only just beginning to unearth if you like some of those effects.
[00:48:30] Jonathan Wolf: I'm all for a personal study to understand, Tim, how I can produce more of these. I'm happy to be the guinea pig and I'm hoping that you tell me that I just watch lots of TV and this solves it, but I have a feeling that it will require more than that.
[00:48:44] Tim Spector: No, it's gonna be lots of ice baths for you I think, Jonathan .
[00:48:48] Jonathan Wolf: I hate this idea and I can tell that I'm gonna be taking an ice bath later this year for certain. Brilliant. Michael and Tim, thank you so much for joining us. Really enjoyed it and I hope we can do it again soon.
[00:49:00] Michael Mosley: Thank you.
[00:49:02] Jonathan Wolf: Thank you, Michael and Tim, for joining me on ZOE Science & Nutrition today. If, based on today's conversation, you'd like to understand how to make sustainable changes to your diet to improve your health, then you may want to try ZOE’s personalized nutrition program.
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As always, I'm your host, Jonathan Wolf. ZOE Science & Nutrition is produced by Fascinate Productions with support from Sharon Feder, Yella Hewings-Martin, and Alex Jones here at ZOE.
See you next time.