5 years after COVID, what did we learn? | Dr. Tim Spector
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Welcome to ZOE Science and Nutrition, where world-leading scientists explain how their research can improve your health. I know, no one wants to talk about COVID anymore. Who wants to live in the past? The thing about the past is we can learn from it. When COVID-19 started spreading across the world, ZOE dropped everything to help. My co-founder, Tim Spector, was in the thick of it. Tim kept us all informed through updates from the ZOE COVID study.

He received an award from the Queen for helping keep the public safe. These dark days are behind us, but what we learned could help us improve our day-to-day health. And could another pandemic be around the corner? Studies suggest that pandemics are becoming increasingly frequent and severe. So are we prepared for the next one?

Today, we learn lessons from the past to help us plan for the future. Tim is one of the world's top 100 most cited scientists, a professor of epidemiology and my scientific co-founder at Zoe. He will break down what really happened during COVID and the things we got right and wrong. You'll leave this episode feeling more confident and equipped for any future virus.

Tim, thank you for joining me today. Great fun. I'm looking forward to it. Well, you know how it goes. We always start with a quick fire round of questions. Are you ready to go? I'm all in, as always. All right. Did Zoe members save lives during COVID? I think they did. Are there ways to reduce the symptoms of long COVID? Some of them. Yes, not all of them. Did you take the COVID vaccine yourself? I did.

At least three times. Can certain foods reduce your risk of getting COVID? Yes. Do you think that you'll see another global pandemic in your lifetime? 50-50. Thank you, Tim. And then finally, what's the biggest misconception about the COVID pandemic, do you think? Oh, there's so many. But I think the global one was it only affected old people. Young people didn't have to worry about it. And that's really before we all knew about long COVID.

So what lots of listeners will know, but also lots of listeners to this podcast won't know, is that Zoe was actually very involved in COVID during the pandemic. And so I think that's another reason that I'd love to look back. So, for example, the reason we started doing anything on YouTube is that we actually uploaded a video to explain to people how to use our brand new free COVID app.

And this was sort of the introduction, right, Tim, for you doing what became regular weekly videos and then made us think, well, we should really go and do a podcast. Yeah, absolutely. We had no idea then what we'd be doing now or that anything we were doing during COVID would have any relevance afterwards. And I think it's only with hindsight looking back that we see, you know, all the amazing things, you know, in this time of disaster, you

some things really worked and not only changed how Zoe works, but also how we changed a lot of the face of research as well, and also interacting with the public. So, you know, lots of things, I think, came out of the interaction between this terrible virus, public reaction and

And companies like Zoe and working with academia and Kings, there's so many lessons I think we learned from it that were very hard to learn at the time because it was at a frenetic pace. And Tim, can you take us back to that time almost five years ago? Like what were we doing at that point before COVID hit? And tell us about like that lead up to this conversation, which I remember very well, where you gave me a call and said, hey, we need to go and do this thing.

So March 2020, Zoe had actually been in existence for nearly three years, which many people don't realize. They think we only started during COVID.

So we were doing this study to see if by giving a thousand people identical meals, whether there was enough difference in their response to these to make a difference. And then we could then predict how people responded differently. This is all in order to get a way of measuring personalization so that we could give people personalized advice.

given the fact that people respond very differently to foods. So this was totally new territory. It was a theoretical idea that we had. There was some very little bit of data, rather, but no one had done this for blood sugar, for blood fats, and gut microbes altogether. And it was by far the biggest study ever done. Huge risk.

But it paid off, and we were able to estimate from these results with our clever computer scientists algorithms that could be used in an app that would then allow people to give personalized scores for their food. So that was where we were, and we were just starting to get the app together. And then suddenly everything came crashing down, and we're told –

In the US and the UK, you know, on virtually the same day, everything had to stop everywhere. So it was like science was suddenly on hold and, you know, science is my life. So it was a terrible feeling. And suddenly felt very depressed and rather lonely as I cycled home and everyone, you know, was either very frightened or...

sad, anxious, depressed, you know, all kinds of emotions going on. But by the time I cycled home half an hour, I'd said, well, there must be something we can do. And my initial idea was to use our twins. We have this huge twin collection in the UK, 15,000 twins all over the country that could be used as

like canaries, if you like, beacons for this pandemic so that we actually work out what's going on. And the idea was to use an app that the team at Zoe had been developing for nutrition and swap it out for COVID.

And so this suddenly transformed me from being super depressed to being energized. And I remember ringing you when I got Hemis, and I got this crazy idea. And far from you dismissing it, which I was expecting, you said, that's great, but we don't have to do just Twins. If it's an app, anyone can download it. We can use it far wider. So you had an even bigger vision of it.

I've got a question. What is your health worth to you? I'm Dr. Will Bolsiewicz, Zoe's U.S. Medical Director. As a clinician, I often think about this question. As the saying goes, health is wealth. The more you invest in it, the more it pays you back. Zoe membership is one of the best investments you can make in your health. Over 100,000 people rely on Zoe membership, our personalized nutrition program, to help them make smarter food choices every day.

It all starts with at-home tests that evaluate your gut health, blood sugar, and blood fat. From your test results, you get a personal report that shows how your body responds to different foods. Then, your Zoe app assigns scores to food and meals to help you make the healthiest choices. After four months, you can retest your gut microbiome. You'll see how far you've come and learn what to do next to improve your health.

We proved it works. In a randomized control trial, many Zoe members reported positive changes to their gut microbiome, energy, and waist circumference. So I ask again, what is your health worth to you? Because with Zoe, it's proven that you can feel healthier in weeks and improve your gut health in months. That's priceless.

Now, back to the show.

I remember this incredibly well because I was in my study which I spent much of the following two years in, right? People who, I'm not a doctor, right? So you were going into hospital and I wasn't. And I remember this call because I think I also felt

"This is awful what's going on, and I really want to be able to do something, and I feel really helpless and useless," which I know talking to lots of people was one of the very common feelings for people who weren't medically trained. And you came up with this idea about how we could use a lot of the technology we've been developing over the last three years, and it felt like we should. It felt like this was really important, and we should stop the business that we were doing and just focus on this pandemic. Yeah, and...

It was great. So getting that positive feedback and our other co-founder, George, was in agreement. And then you got the approval of the investors, didn't you? It was their money after all. Correct. And I think they deserve a shout out, actually, because often people think about these...

these investors as only caring about making money and actually we basically said to them we want to stop doing everything that we're doing on this nutrition science research i know we said we're about to go and turn it into a first product we want to stop all of that and get everybody in the company all the engineers everybody else work full time on a completely free app for the pandemic which has no commercial purpose we just think it's really important and we need to work on it

And amazingly, they just instantly said, yes, that sounds like the right thing to do. You should just do it. We've got your back. And I would actually like to say I'm immensely grateful because I think that they didn't have to say that. And it made me feel really good over the next year when I think we then went on to work ridiculously hard, didn't we? Yeah, it seemed like we were doing about five jobs at once rather than, you know, a lot of people just went home to do the gardening. Do you want to talk through what happened over the next five days?

Yeah, well, I think about 30 people in Zoe at the time. Everyone was super energized by this idea. And like everyone during that time, it was so good to have a purpose. And the team basically worked night and day, at least 20-hour days for five days to get this app up and running because we realized it was totally time-critical.

There'd be all kinds of other things going on and distractions and surveys. And the government was saying they were going to do stuff. Basically, if we wanted to have an impact, it had to be early. And so I couldn't believe that it was ready. And there it was. Okay, it had bugs, it had clunks, it had all kinds of things. But we got it out there. And then with our social media contacts, got lots of celebrities to retweet the link to the app.

We had a million downloads in the first 24 hours, which completely crashed all our rather puny systems and amazed us. But I remember the night we launched, there was a little ticker we had on it just showing the number of people on it. And it was super exciting. And the feedback was immensely positive that people just wanted to be doing something. Because just to remind people that maybe who didn't see this maybe in other countries that

We were asking people to report their state of health.

how are you today? Do you have any of these following symptoms? Have you had a COVID test? And then giving them feedback about their area, about how many people in their area were reporting the similar. So it was very much like the sort of canary in the coal mine idea, but with a million people reporting. And it turned out to exceed our wildest dreams about how popular it was.

Yeah, and I would add that it was built on the technology that we've been working on for the last three years. So we've been doing what in science were like huge remote clinical trials, right? 1,000 people is enormous for human trials historically. And so we built these apps to be able to collect very large amounts of data remotely. In fact, nothing was down for more than a few minutes. And we were able, in fact, to support a million people at the end of the first 24 hours. And we were like 4.5 million people after about a month.

a lot in the UK, but also in Sweden and in the United States. And that basically we sort of had this backend infrastructure. We also understood how to do stuff that was going to be compliant for clinical trials, for clinical research. So you were in the right place, right? We'd built this understanding, but then we needed to know how to use it. And I think we had this amazing support from you and a lot of scientists and doctors at King's College London, right? To understand what were the right questions and problems.

There will be a lot of listeners who participated in what ended up being called the Zoe COVID study. What did we get out of this? And in retrospect, as we look back, was there participation? Many people sort of shared their symptoms every day for a couple of years. Was this worthwhile and valuable? It turned out to be immensely valuable in many different ways.

ways that we hadn't predicted. So the first of all, the thing that people still come up to me in the street and say, "Thank you for everything you did in COVID," was a psychological effect that none of us even thought about. That just by getting people to participate as a giant community, they were helping their own state of mind. This idea of participating and being part of something bigger than just at home isolating.

had a real bonus on their mental health. That psychological impact was probably the most important to the people doing it. Then there was the idea of the things that we were doing for the country and the world. And I think the first thing we were noted for was picking up these new symptoms.

Initially, we were told the only two symptoms definite about COVID were a persistent cough and shortness of breath. We were asking about other symptoms and we very quickly picked up this loss of smell.

that about one in five people were getting. And Tim, for people listening to this who will never have used this app during the time, why were we able to pick up symptoms in a way that there were hundreds of thousands of scientists around the world suddenly thinking about COVID that they weren't able to? Because we were getting daily updates from a million or so people on their current state of health in real time. And

No one else was doing this. Others were depending on slow surveys, still using, you know, even questionnaires. Nothing like this had ever been attempted before. I think there'd been some sort of community studies about people looking at stars and reporting what they were, but nothing in the health sector at all. So this is by far the

sort of mass community study in real time. And it was the idea that every day we were collecting data that was telling us what was happening in every region of these countries.

that not only gave you an idea of the state of the pandemic, so we were able to pick hot spots, which areas were going up, which were going down, but how the disease was changing and how the symptoms were changing and how they were linked to people of different ages and vulnerabilities, etc. So that was really quite key, and no one else had that data. And that's why the loss of smell for everybody and people

We found different symptoms in children and different symptoms in the over 80s with delirium and other things that weren't at all noted. We were the first to point those out. It changed the WHO criteria of the symptom lists.

And most countries change their criteria based on those ZOE results. Based really on all these like, you know, 4 million people participating in this app just sharing their sort of symptoms each day and whether or not they got sick. Exactly. And instantly people saw the scale of what we were doing and the fact we were reporting it very transparently in real time. There was no fiddling of results. It was just, these are the data.

And that's why these major health organizations very rapidly changed their criteria and then changed their public health departments to say, this is what to look out for. You know, it's not just a cough and shortness of breath. There are these other features. It's rather sad that the English government...

English NHS were the last to actually approve these, rather ironically. We were very frustrated. I mean, more than frustrated. I remember we were really angry at the time because we felt people were dying as a result of... Yeah, because they're still going to work or going to parties or meet old people with having completely lost their sense of smell with a government saying, oh, well, we don't believe these results. We're waiting for our own ones to confirm it.

And I remember when we were doing this, like now this all seems a bit obvious, but it was very radical, right? And, you know, my background was sort of big data and internet and stuff like this, but I'd never done anything in health. And you're one of the top scientists in the world, Tim, I don't need to tell you that. And you'd been used to doing what seemed like very large data within science, but like very large data for you was like, you know, you might have to

A few thousand. 12,000 twins and get 1,000 people in a study. So this was something really radically new. And I remember there was a lot of debate about when we were starting, Zoe, was it possible to do real science where you just did it remotely so people weren't coming into a lab or a hospital and where,

If you could get to millions of people, you could discover all sorts of science. It's just not possible with a thousand people coming into a clinic, even though, of course, you always have better medical devices in the hospital, but the trade-off is you get so many more people. Yeah, there was a lot of skepticism at the time and a lot of critics in academia didn't like what we were doing.

They said many things. People will lie to you if you're not seeing them face-to-face. So they're not going to tell you the truth, which turned out not to be true. The other thing was they said no one over 60 is going to use an app. That's what the medical profession generally think of the intelligence of over 60-year-olds. They're incapable of using appraisers. And we showed that blew that out of the water completely. But that was at the time...

It seems mad now, but actually that was the sort of status quo or the reasoning. You don't do studies in older people with technology. And I think they also said you'll never be able to do proper quality science. So did we manage to get proper quality science that was peer-reviewed out of this? Well, we ended up being probably the

leading research group in COVID and the number of high quality papers we got with a number of people. So I think it was over 40 peer-reviewed papers in the very top journals, you know, from New England Journal, Lancet, Nature. Yeah, and these are still very highly cited papers today. They're one of the most important ones. I was looking up the other day, I think the most highly cited is an early one that showed the infection rates

of COVID in people who were working in hospitals compared to the community. And we showed a tenfold increased risk in the US and the UK. And people were the very first ones to show the risks of working in hospitals. And it was also correlated with how well staffed they were with equipment.

You could look at the geography of saying this state or this place had very little PPE and didn't give its staff proper masks, and the rates were even higher. So we were great on symptoms, and as the variants changed, so the symptoms changed, and we had this big debate about it switching to be more like a really starting like a cold, and we spotted that

several weeks before any of the other systems because ours was always much faster. The other thing I think we, these hotspots we were finding in the early stages before there was any testing. We also found a lot about vaccines. So we had over a million people reporting what happened when they took those first vaccines because there was a lot of anxiety about vaccines at the time and a lot of misinformation. And so we

We obviously were able to give independent information about not only what were the side effects of those first vaccines, but how effective they were. And we were the first to confirm in very large numbers what the smaller clinical trials had shown, that these vaccines were protecting people between 70% and 85%.

compared to not having it. And they were reducing severe COVID in big ways. So I think they were the sort of things that I remember as the major things, but there were so many other aspects that we also were fascinating about the spread and the infection rates. And then we were the first really to write about long COVID as well. And I wish we'd been able to do more on long COVID, but

We weren't able to access the people with severe long COVID because they'd been gone to hospital and people in intensive care are obviously not filling in their app. So we always were focusing on the milder cases. And I think that wasn't appreciated by everyone at the time. So we could talk about long COVID in the community, but

But we couldn't talk about those really severe cases. So I think they were the major achievements, as well as we did do stuff about diet and supplements. I'd like to take the opportunity just to thank everybody who participated today.

There were millions of people in the UK and Sweden and the US who did this selflessly and contributed. And I think you just hear like the amount of impact. I think that's amazing. I'd also like to thank everybody at Zoe who worked incredibly hard to make this happen. And it was,

It was really, really intense. I remember juggling this and looking after my then not yet one-year-old with no childcare for the first four months. My wife's a doctor, so she was very busy. So it was a mad time. On the other hand...

You know, it certainly gave me purpose and I think got me through that actually in a way that was much better than many people as I discovered subsequently because I felt like I was very busy and I had a lot of purpose. And so I think actually it was very good for my mental health to feel that in a time that's difficult. But I'd love to look back now at the pandemic and understand, you know, what did we get right across the world? And there were obviously very different reactions in different countries.

And we got wrong. And actually, I'd love to start with something which at the time, I remember, was viewed as complete conspiracy theory, which is where did the virus start and how did it spread? But I understand, Tim, that there's been like more real examinations. So can we start with that? Yes. So I don't think there's any doubt that this virus emanated in China in a place near Wuhan. And the question is, did this come from bats? Did it?

come from a lab that was working on this virus and manipulating it to make it grow faster? Or was it a totally artificially generated virus to cause harm that they then didn't control?

And the initial ideas and the government official response was that this was related to bats and was a natural phenomenon that came out of this market in Wuhan. And it's looking increasingly like that was a bit of a cover-up and that the most likely source of this was a lab leak somewhere.

from Wuhan, and there'd been a lot of US congressional hearings talking about how there'd been work between US labs and Wuhan labs to basically look at the infectiousness of these viruses and how you might control them or speed them up. You said it very calmly, but it sounds quite radical. You're saying genuinely when you look at the sort of the data trail and the science now,

So you think there is quite good evidence to suggest that it might actually have come out of a lab rather than just somehow transferred from an animal to a human being in China completely accidentally? That seems to be the most likely scientific answer for what went on that explains both the epidemiology, the timing, also the trail of

shredded documents and email exchange between the US and China at the time. And there was a very obvious cover-up very early on by various governments saying, we have to get a report out there saying this is all down to bats. So people aren't going to blame labs and scientists to keep that credibility going. So that's my personal view. And there are views on all sides of this. I don't

I think the idea that someone built a virus from scratch would be very easy to do. So I think it's more likely there was a mistake

rather than anything deliberate. But I think these were people working with hazardous viruses that got out of control rather than it being a plot. It's slightly terrifying. I mean, you say that very calmly, but it's slightly terrifying because it does suggest, in a way, it makes it feel more risky that something like this might happen again. I think particularly if this cover-up sort of continues and people don't admit that it actually happened, at least in the US, is quite open. It's interesting in the UK, there's very little coverage of this virus.

And I think it'd be better to be more transparent and say, are there labs around that should be controlled like you would control nuclear weapons?

or anything else that's extremely deadly. So I do think we need more oversight on this because if that is the most likely solution, well, that could happen again in another lab if we're not careful. So let's just keep our eyes open about this. And I think like many things that happened in COVID, there were some things that governments did as if they were in a war situation and they had to take control of everything and make these decisions and some of them were good and some of them were bad. And I think we've just got to be honest about that. And I

I think some of these decisions just need to be now looked at again and perhaps with greater transparency going forward so we can make sure it doesn't happen again.

Well, you slightly shocked me with this one, Tim. So I think I'm going to go on to the next list, which is really about protective measures. And I guess the things that when we think about COVID that we'd never heard of before, but then we got really used to was mask wearing on one side, which, you know, for some people in Asia, they'd obviously been used to, but for the rest of the world, you know, we'd never been used to wearing masks. And the other one is sort of shutting down interactions within society, whether they are

You know, they were called lockdowns in various countries or school closures that we saw across the world. What have we learned about the effectiveness of those protective measures?

Well, mask wearing was very controversial. And basically, most countries divided into two groups of people, the sort of pro or against, a bit like religion. And the early studies didn't show much benefit for masks. And partly that was because people weren't wearing them properly, had them around their chin most of the time, or they were very flimsy cloth ones.

But the latest summary of all the studies shows that proper mask wearing does reduce risk of infection significantly.

And the better the mask, the better the protection. So I think now we know that masks do have some benefit if worn correctly. And a lot of the studies included people who weren't wearing them properly at the time. And we didn't really know exactly what was going on. So that's a good lesson for the future, that if you want to stop a virus that's airborne, make it really hard for that virus to get into your mouth and nose, which is where they get into the body. It makes sort of sense.

The other measures we had on lockdowns, the data is not so clear. I think some countries were able to survive without lockdowns because they had very good medical facilities and the hospitals weren't overrun. And so in that first wave,

They didn't have to stop the whole of society and cause massive economic problems. They had enough hospital beds and doctors and nurses to treat that first wave. For countries like the UK and many states in the US, they weren't able to deal with the huge wave of respiratory problems. And so without having people dying in the streets, some lockdowns

was necessary. Now, whether subsequent lockdowns were effective or not is somewhat debated. I think it's very hard to generalize across every country about whether they are effective or not. We were advising number 10 at one point, a group of epidemiologists, about whether there should be another lockdown or not, looking at all the data. What prevented the virus was the amount of movement of people

And there are these scales for measuring movement. And we were down about 70% or 80% for most of the time during these crises. So if you see people coughing and going to hospital all around you, it's going to change your behavior, whether the government tells you to do things or not. And you would often get these peaks proceeding before the lockdown happened. And so actually, people were deciding themselves whether

to self-isolate and do the sensible thing. So it's not clear that governments need to take this action. It could be that the more vulnerable people made their own decisions to isolate and they didn't need government to do that for them. And what about school closures? School closures were pretty much a disaster. I think that was one thing that got very wrong. I don't think

We really thought through the consequences of stopping children going to school, meeting other kids, interacting with huge mental health sequelae after it. And we got it wrong. We thought that, you know, children were at risk of the virus themselves and, you know,

Turns out it was just very much like a common cold for the vast majority of them, or they had nothing at all. And I think in retrospect, we should have produced much more different rules for children because we had this obsession. If we locked down until they were vaccinated, then they wouldn't carry on infecting other people. It turned out even after vaccination, they were still able to infect people. And so that was a false fallacy. And so they're the ones I think who suffered more

the most during this. And we're seeing this epidemic of mental health issues around the world from this group. And who also suffered educationally, retrograde back a year or so in their education. So that's one thing we got wrong. And the epidemiology expected that children would act the same way as adults.

And I think this is something we need to learn for the future, that there is this payback and that the people who aren't suffering the consequence of it shouldn't sort of pay the most of the penalty. Hi, I have a small favor to ask. We want this podcast to reach as many people as possible as we continue our mission to improve the health of millions. And watching this show grow is what motivates the whole team at Zoe to keep up the really hard work of creating new episodes each week.

So right now, if you could share a link to the show with one friend who would benefit from today's information, it would mean a great deal to me. Thank you.

It reminds me a little bit, interestingly, of like the day-to-day experience that I have at ZOE around extending your healthy years versus, you know, disease and being sick. It feels to me that it's very in line with healthcare in general, which is very, very focused on avoiding somebody dying. And therefore, we put this enormous amount of our resources right into the last six months of someone's life.

and spend almost nothing trying to actually improve people's health before they're really sick and giving them many healthy years. And, you know, Zowie is all about understanding how you can feel better now and you can live more healthy years. And you have people saying, well, aren't you just like, you know, looking after people who aren't sick yet?

And I'm like, yes, because getting many more healthy years is great. And somehow it feels similar. It's like very focused on people who might die from COVID, which is awful. And of course should be avoided. And as I said, I think very much about my parents.

but not really measuring very much the sense about the harm that it was doing to our children and other people who are locked down and all those mental health problems because it's that very measurable death seems to get such a high weighting that I see that in nutrition. But do you think that played into this as well, do you think? Hugely, yes. And you can sort of imagine it from a politician's point of view,

Are you going to say, okay, we'll allow schools to carry on and there's a risk that some of those kids will go and infect their grandparents and those 85 grandparents are going to die maybe a year or two before they would normally die in order those kids can go to school. So...

that's not something that's easy for any politician or anyone public to decide. When you describe it like that, it's an incredibly difficult choice, isn't it? Because, you know, I think one of the things we all felt was our relatives are really important to us, right? And I think one of the things we discovered is we're willing to put up with a lot in order to protect them. It just feels like we created a lot of harm here with children that I think we weren't really aware of. And I think you're saying if we were to redo this, we could have let them go to school and not really affected the death rate very much.

Yeah, absolutely. And I think this is a debate every country needs to have about what is the price of each year of life. Is an 85-year-old living to 86 more important than some child losing a year or two of education and having mental health problems the rest of their life? Or...

These aren't easy things to talk about, but I think in healthcare, the US is even more extreme. It spends about a third of all the US healthcare goes in the last three months of life. And I think we have to start reevaluating this really moving forward as we start putting money into preventive health. The other element that comes in we haven't really discussed is economic. And these lockdowns had huge economic costs.

And epidemiologists know there's a clear link between the economy and health and long-term health outcomes. So I think in future, we also need to be modeling saying, well, you know, for every dollar we're losing, that's going to cause more suffering, more health issues as well. So

it's a much tougher holistic experiment than I think we've realized. And I think next time around, we want to be more prepared into this to say, well, this is the things that make sense. We know these factors are important. Let's have a much more grown-up debate about it rather than just reacting to things. And it sounds like you're saying that in particular, the schools is the thing that you really feel we should have done differently across the globe.

Yes. And it's also how we treated the children. And we know in certain states in the US, they really sort of picked on kids and said, well, you know, even five-year-olds are going to be vaccinated, otherwise they can't go to nursery school or, you know, and there was no science backing this up. And I think we just have to, you know, realize where we made mistakes and

and where we did really well. And, you know, the vaccine story was an incredible success story overall. I was going to say, can we talk about that now? Because, you know, when we were asking for questions on this episode, we had a lot of questions about the potential side effects from vaccines. And we also had questions about

about whether the risks of vaccines actually outweighed the benefits. Have any studies been looking into this? And what is the verdict now looking back? Huge amount of studies looking into this. So for adults, the vaccine prevented 70 to 85%, depending on the vaccine and the timing of COVID infections. It was even slightly greater for severe COVID infections.

it also reduced long COVID. So you're like four or five times less likely to die if you had been vaccinated than if you hadn't. So there were huge differences. And so just to make that really clear, your view today, if advising an adult about whether or not they should take the vaccine is... Well, I mean, I took the vaccine and I was very glad I took it. Obviously, you're reducing your risk of getting that infection. And if that infection is likely to be

have a risk of death, then you're going to reduce that equally. As each phase of the COVID gets weaker, more infectious. So what's happened is exactly as predicted. Each variant of the virus has become cleverer at evading our immune systems.

And it's kept mutating. And so it's even more infectious than it was right at the beginning. But it's much less likely to harm us severely or kill us. And so this is what happened to the original Spanish 1917 influenza pandemic virus.

And it took about seven or eight years for it to blend into the background. So when we talk about vaccines now, it is different to what it was in 2020 when the mortality rate was huge. Still, we think about 20 million people worldwide have died of COVID. So I'm not trivializing this any way. Which is an enormous number of people, right, from something that didn't exist six years ago.

Correct, and just seemed to come out of nowhere. But it would have been many more if we hadn't had the vaccine. And so what do you say, there's lots of people who talk about side effects and focus on those side effects. As a doctor and a scientist looking at the data now, how would you help someone who's worrying about that and trying to understand, did they do the right thing? And indeed, if they are thinking about vaccines today. These COVID vaccines do have side effects. And because this is probably the most studied vaccine in history...

Even in our Zoe survey, we had over a million people we were looking at. We could see these rare side effects quite well. And you can get problems of the heart, myocarditis, pericarditis, occasional brain problems. But you get like 10 or 20 times more if you get the infection.

So yes, there are side effects of the vaccine, which is giving you the virus in a mild form. But if you have the virus in the full form, the wild form, you're going to get many times more. So that's why for adults, the risk-benefit ratio is, for the vast majority of people, always positive.

For children, it wasn't the case. So they didn't get the same advantages because they were relatively protected against the virus. What you're saying is if they got the virus, they weren't likely to be sick? Much less likely to be sick or have major heart problems or die. And therefore, in many cases, the risk of the side effects was greater as the risks of the actual virus itself. So

I think most countries moved away from vaccinating children fairly early, but some stuck with it, particularly some US states. So I think that's where a lot of this controversy lies. But there's a big difference between talking about children and talking about the average sort of 50 to 70-year-old person.

You know, everyone's got their own personal story. These vaccines wane after time. So it depends when you're taking it. And when people are listening to this podcast, there might be a vaccine that's just come out that's really good against the latest variant. And it's just coming up to winter and you want to be protected. That's when it happens. You're offered another one that's, you know, just about to go out of date. It's really good against the old variant and that's changed and actually improved.

you're coming up to summer and there's not much going on and therefore you're better off waiting. So it's become slightly more subtle in terms of what we do, but I don't think because of these subtleties and these rare side effects, we should in any way think that vaccines in general are problematic. Because of COVID, there's been this terrible anti-vax movement that's sort of

thrown out everything. And so suddenly saying, well, we can't believe anything these guys are telling us. And therefore, you know, kids are now dying of measles, really important cervical cancer vaccines are not being taken up. And we're not using this incredible technology that was the whole world got together to get together to fight cancer and things like this. So let's be sensible about these things.

and in general, follow the advice because the value of vaccines is huge. Got it. And here, what you're saying is, overall, the vaccines were great, but in children, when we look at the risk-reward, particularly, I think you're saying for younger children, actually, the risks from COVID were really overstated. They were very low, and therefore, when you look at these rare side effects, it's like, well, those risks...

or as high or higher than COVID. So it doesn't make sense there, but I'm nearly 50 or I think about my parents in their 70s, you're saying it was a very different calculation.

Yes, and as you get older or you have a medical condition, then that ratio changes. And what about today, Tim? Because I'm really struck how much COVID is still going around. I sort of had this thing, oh, everyone's got a vaccine, it'll disappear, you'll never hear about it ever again. And I'm struck by how many people say, oh, I can't come to this event. I'm really sick and my whole family's sick and we've got COVID. And some people getting really sick with it, I noticed. Like some people feeling really unwell for long periods of time.

What does that mean about people thinking about vaccination today as opposed to, you know, presumably already having had previous vaccines during the pandemic? Yeah, I think the big worry now is not so much death. It's more about long COVID. And the current estimates are that around 10% of the people are being infected today.

are going to have some degree of long COVID, which means it's going to last at least three months. And that means many people are left with all kinds of weird configuration of symptoms that is going to impair their life. And we do know that vaccines reduce the risk of long COVID estimates something about 50 and 80%. So that's probably the main reason to be taking it. And strangely enough,

we would have thought that if you had COVID multiple times, oh, well, you're not at risk of long COVID. But actually, the more times you've had it, it slightly increases. So it doesn't disappear automatically.

People would assume that, oh, I've had it once and I didn't get long COVID, I'll be fine. You've incredibly depressed me because I assumed until 30 seconds ago, I've had COVID after my vaccine and I didn't get long COVID, so I'm totally fine. And now you're pulling the rug out from underneath me, Tim. I believe that as well. I thought, oh, I'll be fine. But I think there is still this risk of long COVID, which is probably the major one that's still hanging over us.

And it has a major psychological, financial, economic, everything component. Everyone who's been through long COVID or is still suffering knows how important it is. So I think that's the main consideration that we shouldn't just completely ignore

These new variants and these threats, you know, we're not out of the woods yet. And are a lot of people getting long COVID? There are, yes. So those numbers haven't really dropped. And it's not in the news and they don't get the attention they deserve. And as yet, we haven't really found a cure for long COVID. So there have been lots of trials done and we're getting better at spotting the symptoms, but there's no magic test yet.

It's not been easy for the medical profession to try and work out what's going on. Some signs we can deal with some of these symptoms, but the ones with tiredness, et cetera, we've made lots of mistakes. We used to tell people with long COVID to exercise more, just get out there and pull yourself together and go for a long walk.

90% of people got worse when you did that. So actually, that was the wrong advice. Advice is really to rest. So we've still got a long way to go in dealing with long COVID and the results of that. So, you know, there are millions of people around the world who are still suffering. And I think we, you know,

We shouldn't forget them because as people like ourselves are trying to move on, there are many people who can't. And I think that's very important. And there are a few promising drugs around, but they seem to be treating individual symptoms rather than the whole thing. Well, I think it makes you realize just how terrible a virus this is and has been, doesn't it? Because not only, I mean, there will be lots of people listening to this who lost loved ones during COVID. I know many people who lost loved ones.

parents and other relatives, many people obviously who suffered really significant mental health issues, but then people still living with long COVID but still getting it now and makes you realize just, you know, the world is a worse place as a result of this COVID being out there than it was, is really depressing. And I guess it's a good transition to the final things I'd like to touch on really, which you mentioned, you know, in the quickfire at the beginning about the risk of another pandemic.

that this might not be the only time this happened. You said it was 50-50 in your own lifetime whether we had this again. And I know the team shared some research showing that these pandemics are getting more frequent and severe if you look across history. I think I'd like to focus on what people can do to prepare rather than... I think maybe there's a whole other podcast about what governments might be able to do, but...

you know what can people do and given that this is zoe science and nutrition i'd maybe like to come back to that quick fire answer question right at the beginning where you said well actually there's things you can do with your diet that can really reduce your chance of getting covid and reduce the severity because i think some people listening that would be like well that sounds totally crazy like total quackery and i think the first time i heard you talk about this i was like surely not

Obviously, the last thing most doctors talk about is diet. That's why we tested about 100 different drugs in COVID and people still obsessed with the anti-worm drug, ivermectin, as being useful, although 14 randomized trials have proven it doesn't work. But we did a study of a million people, followed them up and worked out how severely they got COVID. And there was a clear relationship that it was the strongest factor after age.

was the quality of their diet. And if they had a high ultra-processed food diet, high inflammatory-causing diet, lack of fiber, all these things had a surprisingly high impact on their risk of having severe COVID. I think it didn't so much stop you getting it, but it stopped it being really bad. So the first thing...

anyone listening to this can do about preventing any sort of nasty illness that's going to impact your immune system is to build up your immune system. How do you do that? Improving your gut microbiome. And how do you do that? Through your diet. People are going through the ZOE nutritional program will know exactly what I'm talking about. It's basically this idea of more plants, diversity, high fiber, feeding your gut microbes,

in a way that is going to help your immune system. So that's number one. The other is try and keep your weight under control. So obesity turned out to be quite a major factor. There's some evidence that people taking metformin, interestingly, which is a drug that's been around for 30 years treating type 2 diabetes and is being researched now as an anti-aging drug, can actually...

reduce risk of infection. But we don't know whether that would work for avian flu or anything else. But there's an interaction between some of the drugs people commonly take and our immune system that we still don't understand much about. If someone's listening to this, they might well have the same response that I had originally, which is like, you know, I understand how eating food could affect my weight. I can sort of understand how it affects my

mood now because you sort of talk about the bacteria making things. I can sort of get there, but sort of the preventing me, you know, getting really sick with a virus, it sounds like a sort of crazy stretch. How does this work? To understand how you might fight off an infection or keep it minimal under control through your diet,

You've got to understand the link between the food you eat and your gut microbes and your gut microbes and your immune system. We now know that most of our immune system is in our gut, 70% to 80% of it. And the way it gets its signals and it understands what's going on around it is through the gut microbes, most of which are in our lower intestine. There are 100 trillion of them, same number of cells in our body.

And we all have very personal different ones. And you can change them rapidly within a few days by altering your diet. And the healthier your gut microbes, the more diverse they are, the more good ones, the less bad ones, better you're going to be able to control your immune system. And if you control your immune system, this means it's going to react appropriately to

to, say, a virus. It's able to fine-tune your defenses, and it's not going to waste lots of energy. So people eating a junk food diet, very little fiber, and a typical American diet is going to have an inflamed gut microbiome that's going everywhere. It's all distracted. It's trying to put out fires all over the place. And so when

real virus comes along, it's not able to really pin it down. So that's why keeping our immune system in perfect health is really crucial. Not only is that good for infections, but that's also good for aging and also fighting cancer. It's the same principle. That's why microbiome and diet keep coming up in all these diseases. So if you want to have the best immune system, you need to make sure your gut health is in the best possible way.

And as our members know, it's plant diversity, it's fermented foods, which we now know are really good for the immune system. And this means foods with probiotics in them, live microbes. And it also means not having ultra-processed foods and getting plenty of fiber in there.

I can't stress enough that's the reason that we saw these big differences in social class effects on severity as well. It's all linked to diet as much as anything else.

And so does that mean that when I'm feeling sick, you know, the way I historically would have responded to that was, I'm just going to eat loads of junk because I'm not feeling very well. So I think just indulge myself. I historically thought that seemed perfectly reasonable. After all, you're not sick most of the time. So it's a time, you know, to throw...

anything you might think about healthiness away, is that fine? Or actually, when you're sick, should you almost be doubling down on making sure that you're eating, you know, these foods that are supporting your good microbes? No one's done the study of suggesting that people like you go and, you know, divide into two groups. But all the evidence suggests that we should be

really focusing on immune-boosting nutrition when we're sick and not going for the comfort food? I definitely think a lot more now about like, okay, am I still eating sort of good food that is supporting my microbiome in that situation that I would have done? It's like one of the things I think I've really...

So I understand you saying that there's not the proof, but it's definitely changed my mind because I've sort of got this idea. I want to keep the microbes helping me out. I don't want to because I can tell I'm in like a sort of internal battle. You know, we're getting this evidence from our studies like if you have a poor night's sleep, you feel terrible and your brain sort of picks the wrong foods for you.

to make you carry on feeling even more terrible. So I think we've got to start realizing there is this really close link between our brain, how we're feeling, our immune systems, and the diet. But let's not lose track of what our gut microbes need in order to keep the immune system going is even more crucial. So, you know, there was some tentative evidence that things like probiotics could help artificial versions of fermented foods. And so, yeah, if...

Next time I get COVID, and I have done the last few times, I am really hitting the fermented foods and making sure I'm getting plenty of fiber. Tim, many more questions, but we definitely hit time. Thank you. I'm going to try and do a quick summary question.

across this, as always. So I think we started by saying that there's been an opportunity to reassess everything because we have distance and data. And this is like one of them, you said it's like the most studied virus ever. There are a set of things that I think we've come through and we feel really good about. So you said, you know, we feel really good about the vaccines. They've turned out to be safe. They saved many, many lives.

There's things like masks where you're saying, now that we've been able to examine this clearly, it is clear that if you wear the mask correctly, it can really reduce your risk of infection. But a lot of people were failing to do that. But other things, you know, you've said you've really rethought and that particularly you feel that our approach with children was wrong, that closing schools was wrong, and that indeed that the balance of risk was

for young children on vaccination was also wrong because their risk of getting COVID and being hurt was so low that actually you were at the same level of risk as a vaccine. Then we talked a bit about long COVID and the fact that not only is this real, but it's continuing. And one of the things that is a negative surprise is even people like me or you who've had COVID, we aren't guaranteed to be safe from long COVID and from a future infection, which makes you think you'd rather not get it, but it's going round and round.

Future vaccination, you know, for people who've already had vaccines can make sense, but you need to be at an at-risk group and you'd really like to be having the vaccination that's actually well-targeted

to the current version of the vaccine, not the one from five years ago. And then I think we got onto this really interesting topic about like what can you do to protect yourself from infections in the future, whether that is a future pandemic or just flu, COVID, any of these sort of things. And this amazing data that the foods you eat

was one of the biggest things that could change, you know, your risk of getting really sick with COVID because we now understand that the food we eat has this profound impact on our gut microbes that then has this, you know, profound impact on our immune system. And so by eating the food that is really going to support the right microbes, we can actually really improve our immune system. And I think it doesn't, you said it doesn't guarantee we won't get sick, but it

but it basically means that we're much less likely to get severely sick. Yeah, prolonged infections and some evidence preventing long COVID as well. So the message, as is so often here, is what you eat is centrally important and somehow the more we study it, the more we understand how much it impacts every aspect of our health. Absolutely. Yeah.

Tim, thank you so much. And I will wrap up again, as I said, you know, at the beginning to thank so many people, both listeners and non-listeners who participated in everything during COVID five years ago. And I would just say, I think...

I feel very proud, actually, of my part in this. I think when I look back on the whole Zoe story, it's the thing I'm going to feel proudest about by far. And I think everyone listening who took part in those studies or, frankly, did anything during COVID that was helping other people should feel really proud because I think it was a very difficult time. And I hope you're wrong, Tim, and that there will not be another pandemic in your or my lifetime.

I very much hope so too. But yes, no, thank you everyone. It was fantastic and very emotional really to revisit those times and realize what an amazing team we and the millions of other people were. And it just shows what you can achieve when we work together. I love that, Tim. Thank you so much. I really loved having Tim on the podcast as always.

And my biggest takeaway is that we really need to learn the lessons from the COVID pandemic because there's a very real risk that there will be another pandemic in our lifetime. And one of the big lessons is that the food we eat is one of the most important things we can do to improve our health and make us better at fighting the next virus. And that's where Zoe membership can help you. Each day, more than 100,000 people rely on our personalized nutrition program to make smarter food choices.

to feel better in weeks and be on track for more healthy years. So how does it work? Zoe membership starts with at-home testing to understand your unique body. Then Zoe's app is your health coach using weekly check-ins and daily guidance to help you shift your food choices to steadily improve your health. I rely on Zoe's advice every day and truly it has transformed how I feel. Will you give Zoe a try? The first step is easy. Take our free quiz to find out what Zoe membership could do for you.

Simply go to zoe.com slash podcast, whereas a podcast listener, you'll get 10% off. As always, I'm your host, Jonathan Wolfe. Zoe Science and Nutrition is produced by Julie Pinero, Sam Durham, and Richard Willett. The Zoe Science and Nutrition podcast is not medical advice. And if you have any medical concerns, please consult your doctor. See you next time.