Updated 23rd June 2022

Inflammation, aging, and disease: What's food got to do with it?

It’s a biological process that we need to stay alive. Yet too much of it leads to disease and a shorter life. 

Inflammation is the immune system’s response to an outside event it thinks is dangerous. This stimulus could be an injury, like falling off your bike or an infection by a virus or bacteria. But inflammation can also be triggered by our food in the hours after we eat. 

But if this natural process is required to protect us from infections and injuries, why is inflammation usually cast in a negative light? Is there something behind this, or is the idea that inflammation is bad a lie, designed to sell magic potions with dubious evidence?

In this podcast, Jonathan speaks to two show regulars to unravel all the information about inflammation.

Dr. Sarah Berry is one of the world's leading experts on human nutrition, who has personally run over 20 randomized clinical trials looking at how humans respond to different fats.

Tim Spector is a co-founder at ZOE and one of the top 100 most cited scientists in the world.

If you want to uncover the right foods for your body, head to joinzoe.com/podcast and get 10% off your personalized nutrition program.

Transcript

[00:00:00] Jonathan Wolf: Welcome to ZOE science and nutrition, where world-leading scientists explain how their research can improve your health.

Today we discuss a biological process that we need to stay alive. Yet too much of it, leads to disease and a shorter life. Most of us have heard of it, but don't really understand what it is. When linked to food, you almost certainly have an opinion. Many of you like me, will have assumed any relationship was quack science.

It turns out we were wrong. The process I'm describing is inflammation, which put simply, is the immune system's response to an outside event it thinks is dangerous. This stimulus could be an injury like falling off your bike or an infection by a virus or bacteria, but inflammation can also be triggered by food in the hours after we eat.

In all these cases, the immune system activates processes designed to heal the body. But if this natural process is required to protect us from infections and injuries, why is inflammation usually cast in a negative light? Is there something behind this or is the idea that inflammation is bad, simply a lie designed to sell magic potions with dubious evidence.

As it turns out if inflammation continues for long periods, it can have a severe negative impact on our health. Long-term inflammation is now linked to many major diseases from dementia to heart disease. Recent research has shown that what we eat can be an important cause of long-term inflammation. This dietary inflammation can be caused by repeated shocks from the food we eat month after month, year after year.

This long-term inflammation has severe implications for our health, increasing the risk of serious disease and potentially weight gain, and accelerated aging. In today's show, we find out how we can reduce dietary inflammation, which foods can help, and discover how our gut microbiome could play an important role.

I'm joined once again by two of our regulars, Tim Spector, one of the world's top 100 most cited scientists, and Sarah Berry, one of the world's leading experts in human nutrition. Sarah has carried out more than 20 human clinical trials investigating the inflammatory processes, triggered by different types of food.

Sarah and Tim, thank you for joining me today. As regular listeners will know, we like to start with a quick fire round of questions from our listeners before then going into more detail. So I have three questions here for Tim and then three for Sarah. So Tim, is all inflammation bad for you? 

[00:02:46] Tim Spector: Short answer is no. We need inflammation to stay alive because it protects us against injuries, cuts infections, and foreign bodies fight them off. So when it goes wrong, it's bad, but generally, we need it. It's part of our defenses. 

[00:03:03] Jonathan Wolf: Which I think will surprise a lot of people. Second one. Is inflammation from food a real thing? 

[00:03:11] Tim Spector: Short answer is yes. And the reason's actually quite complicated and it's not just all about allergy.

[00:03:17] Jonathan Wolf: Can inflammation cause aging? 

[00:03:21] Tim Spector: It can certainly be a major factor in aging and getting the balance right of our immune system is found to be crucial in how we age. 

[00:03:31] Jonathan Wolf: Amazing. Sarah, is there a link between processed foods and inflammation?

[00:03:37] Sarah Berry: Yeah, there is. 

[00:03:38] Jonathan Wolf: Sarah is going to go short and sweet today, I can see. Can eat too much fat cause inflammation?

[00:03:44] Sarah Berry: Depends on the type of fat, but more importantly the meal that is consumed in. 

[00:03:49] Jonathan Wolf: Are there specific inflammatory foods you should exclude from your diet? 

[00:03:54] Sarah Berry: I'm not going to demonize any single food. But yes, there are some foods that we know are more pro-inflammatory, but it's really dependent on the overall dietary pattern.

[00:04:04] Jonathan Wolf: Brilliant. And I think we'll figure all of that now over the rest of the podcast. So as we kick off, I have to admit that five years ago, I thought inflammation related to food was some sort of pseudo-science thing, you know, an excuse for crazy diets and weird detoxes. And so I'm sure for a lot of our listeners is very surprising to hear that this inflammation thing is real and that this is important.

And so Tim, maybe can you help us just to understand a bit more what inflammation is, why it happens? And I think probably surprised many of us by saying it's not always a bad thing. 

[00:04:37] Tim Spector: Yeah. So we've evolved to have this process of inflammation, which is the body's natural response to any threats or injury. So when you knock your hands and maybe get a small cut on your arm, it's bruising, and that signals the body to send out chemicals to basically repair that area.

So you get an instant response of some blood going there to stop the bleeding. If there are a few foreign bodies in there, you get some white cells that come to actually attack the invaders. And at the same time you get changes in the blood vessels, which open them up, make more blood flow in that area so that it can help get defense chemicals there and take away any rubbish and damage.

So, all that is what's going on inside when, on the outside, you're seeing redness, pain, swelling, et cetera, which is what we call inflammation. And in a way that's going on all around our body all the time as a natural defense mechanism. And we're learning more and more that this basic mechanism, goes on to prevent all kinds of diseases and all our cell processes and to a lesser extent is also helping us just mop up all the chemicals that get produced as a side effect of day-to-day life. Just like in a factory, you get these electric sparks in machine works. Our body produces these free radicals, and then you have our body coming and mopping up those and taking them away. so that we can continue our normal function.

That's really important to realize that inflammation is our friend. And like most of these processes in pathology, it's only when it goes wrong or the fine tuning of it goes out of kilter, do we end up with problems. 

[00:06:37] Jonathan Wolf: And when you talk about it going wrong, what does that mean? And you gave this example, like cutting yourself. That's very straightforward. And also the thing of by-product from food is it triggered in other ways? And what does it mean when you say it goes wrong? 

[00:06:52] Tim Spector: Well, it can go wrong for a number of reasons. So you might have developed some disease, like an auto immune disease where you're getting an unnatural response to your own body.

And that also happens with food allergies. So it thinks it's a threat and it's not really a threat, but it's like it is. And so it continues and it can't get rid of it as it would do. And therefore you get this chronic inflammation, you might have some infections like tuberculosis that are hard to get rid of. And you can end up with this longstanding inflammation that you can't shift.

And increasingly we're finding out that lots of chronic diseases get to a certain state that if the body can't correct the metabolic problem, you continue with this low-grade inflammation that sort of is just trying to deal as if it's an acute injury, doesn't quite work. So you get this low-grade inflammation. So that's diseases, and that also happens with aging, as your body is less able to really fine tune this narrow line between fighting off infection in the immune system. And we also know that food affects it so if you are regularly eating the wrong kinds of food, you can also develop short-term peaks of inflammation that lead to a long-term inflammatory pattern, just because your body's not quite responding well, it's just overreactive to some of these things that perhaps when you were young and healthy, you wouldn't have reacted to. 

[00:08:23] Sarah Berry: Yeah, I think as well, modern life is not the friend of inflammation as well, because we know that so many of the lifestyle and dietary factors that now changed in how we live our life, impact inflammation. And I think this is something often people don't think about.

So we know that sleep deprivation stimulates chronic inflammation. And we know that from sleep studies where people were asked to limit their sleep and then you can look at inflammatory measures. We know stress directly causes inflammation. We know that diet, as Tim said, causes inflammation as well. And we know that having a moderate level of activity, say a moderate level of exercise can actually have anti-inflammatory properties.

And so the way that we live our lives in a sedentary, often sleep deprived, stressful state, is really not helping matters. And it is also within our current food environment as well. 

[00:09:13] Jonathan Wolf: So those of us with small children working from home may not be in the optimal situation to manage their information. Is that what you're saying, Sarah? 

[00:09:22] Sarah Berry: It means you and I are stuffed, Jonathan. 

[00:09:26] Tim Spector: Just before we go on, just a big difference is to say, that there's a difference between acute inflammation, which is what happens when you get an infection or you, you know, you get COVID or whatever it is, and chronic inflammation, which lasts months or years. And I think that's an important distinction because acute inflammation is fine and not a problem but if you have repeated acute inflammations, that leads often to this long-term or what we call a chronic state of inflammation. And that's really what we're trying to avoid. 

[00:09:59] Sarah Berry: We now know that actually most chronic diseases are underpinned by inflammation, that we know that whether it's heart disease, type two diabetes, or some mental health disorders have been linked to inflammation.

Also dementia. Alzheimer's. Some cancers as well. So we know that if we can start to tackle some of this chronic inflammation that Tim talked about, we might be able to somewhat attenuate our risk of some of these more chronic inflammatory driven diseases. 

[00:10:28] Jonathan Wolf: And so how does food fit into this? And Sarah, I know this is one of your big areas of research, right? How does food affect our body in the hours after we eat? Is there such a thing as, sort of, dietary inflammation? And if so, could you help us to understand how that fits into this picture, Tim has drawn, between sort of short-term inflammation, good. Keeps us alive. So we like that. Long-term inflammation, I think you're saying, tying into all of this really bad impact on our health. 

[00:10:56] Sarah Berry: Yes. There are two different ways I think we can think about how diet impacts inflammation. One is how food is actually metabolized. And I'll pick up on this in a minute, but also how the food itself might directly impact our inflammatory response.

So there are two different ways that food can impact these inflammatory pathways. But the good news is then it kind of gives us two bites of the cherry that there are two different kinds of strategies we can take with our diet in order to minimize inflammatory responses from food or other external stimuli.

So when we consume foods, we consume foods that contain mixed nutrients, so they typically contain fat, carbohydrate, protein, and fiber. What we know is that when we consume any fat in the food, we have an increase in circulating blood fat, and we have an increase from the carbohydrates in the meal and circulating blood sugar.

This happens really quickly. So your blood sugar can peak within about 30 minutes in the blood and your blood fat can peak within about four hours, in the blood. But what's important is this initiates a kind of cascade of events and a good way of thinking of it is it sets off like these mini fires of inflammation in your blood that affect the lining of your blood vessels and have other downstream unfavorable favorable effects.

So given that most of us don't just consume one meal a day, given that we consume multiple meals, and given that many of us also consume quite highly processed food, that's really rapidly digested, this means that throughout the day, you've got all of these fires burning throughout your body stimulated by this increase in blood sugar and blood fat and over day after day repeated.

And if you don't have suitable defenses in place from other properties of the food, then you're in this chronic state of inflammation. The good news is though that you can partly reduce your excursions, these peaks in blood fat and these peaks in blood glucose, but also there are components in food that can kind of dampen, sort of, put out the fire. So act a bit like a firefighter. And a really good example of this is polyphenols. So polyphenols are found in extra virgin olive oil and lots of highly pigmented, fruits and vegetables. And I think a nice way to illustrate this is a study that was done some years ago, where they fed people a really high-fat meal, consisting of refined olive oil, which means basically it's just like consuming a typical vegetable oil that you'd get in a supermarket. So it has none of these, like, wonderful bioactives of polyphenols and then they fed people a really high-fat meal consisting of extra virgin olive oil. When they fed the people, the meal that contained the refined olive oil, you had a really big increase in circulating blood fats. You had a really big increase in inflammation and oxidative stress. When they fed people, the extra virgin olive oil, you had the same level of increase in blood fats. You still had this increase in blood fat and therefore kind of a spark of a fire going off, but actually, the polyphenols in this put down that fire and meant that there was hardly any increase in inflammation, hardly any increase in oxidative stress. And also there was almost no effect on the functioning of the blood vessels, which is the ultimate downstream, kind of harmful effect that we see in this post-meal state, from this inflammation.

[00:14:15] Jonathan Wolf: Got it. And how does the microbiome fit into this story? Because you're talking about these protective elements, how do bacteria fit into this story of inflammation, if they do at all? 

[00:14:25] Tim Spector: Yeah, the microbiome is incredibly complex at the moment it's made up of trillions of individual microbes. We're all very individual and these are like chemical factories. So what we know is that many of the ways in which fats and sugar are broken down are in part controlled by our gut microbes. So there's, in a way, a direct effect, particularly we know much more about the fat pathways because we know that microbes actually produce many of the things like bile salts and other enzymes that break down fat and allow it to get re-circulated into the body, which we only thought they only occurred in the liver. We now know that actually, our individual gut microbes do a lot of this. So having the right sets of gut microbes will help you break down fats. So they don't hang around in your body after six hours and lead to this stressful inflammation. So true. We don't really understand how microbes currently influence blood sugar. We know they do to some extent, but we don't know where that happens, probably because it occurs in bits of the intestine that are hard to reach and hard to study, like the small intestine. But the other general picture about inflammation sort of says, well, can microbes control inflammation in general? The evidence is overwhelming yes because we know that there are pro-inflammatory microbes. We know the anti-inflammatory microbes that when you do experiments between humans and rodents, you can create inflammation in some mice and then transplant their poo sample to sterile mice, and they will cause that inflammation. In those animals. 

[00:16:16] Jonathan Wolf: And sorry, Tim, you're saying you transfer, what? Do you transfer from the mice with inflammation, to the other mouse? 

[00:16:23] Tim Spector: Well, you can transfer inflammation from one mouse to another via their microbes. So it's just suggesting that the microbe is then the source of the inflammation and not purely a secondary event. And you do that against controls.

[00:16:38] Jonathan Wolf: Got it, so that's amazing. So basically you're saying the mouse is completely sane. None of the things you described before with infection or cutting the mouse or any of the rest of it, just their microbes. 

[00:16:46] Tim Spector: It's the sterile mice, for example. And you compare with inflammatory microbes, and they've come from humans and normal control microbes from humans and put them in mice and the inflammatory one will produce a similar inflammation in the mouse. So that's why we know it's not just correlation. There's a causal element to it. 

[00:17:08] Jonathan Wolf: It's amazing. Right. So you're basically saying these completely other organisms, we don't think about it as being part of us. We transfer them to somebody else. And suddenly it's affecting this very complex system you're describing around inflammation that is, you're also saying impacting so many of our long-term health and things like this. It's... If you'd said this 20 years ago, right? People would've said you were probably crazy. 

[00:17:31] Tim Spector: They would've definitely locked me up. Yeah. That's true. They're trying to now, but I get away!

Yeah, so we have this really good base, where you take human samples of the disease. Then obviously these people, people with particular autoimmune disease or these chronic infections who have longstanding inflammation and you can make sterile mice quite sick with the same ones. And so we also know that that can be partly reversed and that by putting in a whole series of anti-inflammatory microbes, you can partly reverse this process.

And when you look at the difference between studies, microbiome studies of healthy versus unhealthy people with chronic inflammation, they always have a lack of these anti-inflammatory microbes, which all healthy people have, which seemed to dampen down inflammation. And, generally all these unhealthy groups, all those chronic diseases tend to have microbes that really like inflammation and rub their hands with glee when they're in a nice environment and inflamed environment, perhaps because the acidity has slightly changed or the environment around is slightly changed, that they just love that, and they do really well.

And we think that they produce pro-inflammatory messages, substances to keep the whole process going. So they're both a marker of inflammation, but they're also probably a driver as well. And so increasingly we see that the microbiome is key to inflammation. And the good thing about the microbiome as opposed to our genes is that we can manipulate it through diet and through drugs and through antibiotics, probiotics, etcetera.

[00:19:17] Jonathan Wolf: And so you've painted this picture where the information could be reduced, both through aspects of our food. I love this idea of them as firefighting and these microbes themselves could either be arsonists or firefighters, depending upon which we have. Sarah, could you, cause I know this is something that you study a lot, could you help us to understand how you move from this sort of immediate inflammation after a meal? Eventually these impacts on your long-term health that you touched on earlier. Cause I think it's not really clear this link between the two. 

[00:19:49] Sarah Berry: So imagine you've got these constant fires going off that we talked about, your body and the other food components are trying to dampen it and put out, but eventually you'll kind of like, on this tipping scale of, trying to constantly balance this out and sometimes either the defenses in the food that we're actually eating or the defenses from our body just aren't strong enough and, you know, tips us over the balance and it puts us into this more constant pro inflammatory state, but also, as well as increasing our baseline inflammation. So, our kind of fasting inflammation, as we can think of it, we do know that all of these short, short rises and inflammation, these fires that are going on, cause immediate damage. So we know that they impact, for example, how our blood vessels function. And so we've done lots of studies at King's where we feed people, different types of fats or different types of foods. We look postprandially, so we look post-meal at their changes in the fat and in the sugar in the blood, we look at changes in inflammation, and we also look at actually, physical changes in how their blood vessels function, and there are particular techniques that we use using ultrasound, for example, where we can look at how healthy the blood vessels are. And we actually see just within a six-hour period, if the initiation. of this inflammatory response post-meal and impairment in how your blood vessels function.

And you can actually see physical changes, we know from mechanistic studies as well in the lining of the blood vessels, which is causing this deterioration. And over time, this can lead up to what we call atherosclerosis, which is a kind of furring of our arteries. That's just kind of one example of how it impacts us, and therefore affects, in this case, cardiovascular disease, you have similar kind of pathologies going on at the level of the pancreas where repeated inflammation of the pancreas, which is really important in terms of insulin resistance, because it produces insulin where it affects the functioning of the cells, I'll be to cells in the pancreas and therefore also can affect the production of insulin. And that downstream affects our risk of type two diabetes, which then triggers a whole cascade of other effects related to cardiovascular disease, obesity, et cetera. 

[00:22:10] Tim Spector: And I can attest to that because Sarah actually tested me after giving me massive amounts of cheddar cheese and dairy milk chocolate to eat. So I did those ultrasound studies. 

[00:22:22] Jonathan Wolf: And how did you do Tim? 

[00:22:24] Tim Spector: Well, I had actually a very high-fat response if I remember, but the vessel response was actually quite good. There was still quite elastic. 

[00:22:32] Sarah Berry: Yeah, Tim was, the epitome of a healthy 18-year-old, so although he had a reasonably high-fat response, his body defenses to putting out that fire was fantastic. So the ultrasonographer that did the research on him was quite shocked. And we did actually go back and check his results because we couldn't believe, not saying that he's much older than 18, Jonathan! 

[00:22:54] Jonathan Wolf: So that's all of those good microbes. That's good to hear.

[00:22:57] Sarah Berry: So say this is the best ad for, for eat like, Tim Spector, and then you'll have an 18-year-old blood vessel. 

[00:23:03] Tim Spector: Great bouncy blood vessels. I think that was the point. But, so we've got this chronic inflammation and it is linked to putting on weight. We haven't really discussed that, but it is linked to weight gain. And we can talk in general about the whole system being stressed and the metabolism being stressed, and everything slightly on the curve. Do we really know why chronic inflammation is linked to weight gain in specific mechanisms? 

[00:23:28] Sarah Berry: I don't think there's clear enough evidence. I think what's really clear is that increasing weight, so if we can look in the other direction first, we know that body fat produces inflammatory compounds. So we know that if you put on weight, you increase your baseline inflammation. Hence one of the mechanisms, is why obesity predisposes you to all of these kinds of chronic inflammatory conditions, like type two diabetes, and cardiovascular disease. We know from weight loss studies, that as soon as you lose weight, even if you haven't changed your diet, in terms of the quality of the diet, but you've lost weight, we know that you can have a big reduction in many of these inflammatory compounds. How it works in the reverse, we don't understand yet, but mainly because it hasn't been looked at in a lot of detail, we do know that there is some evidence that inflammation is a precursor for weight gain. We know that as I said a minute ago, it increases insulin resistance and type two diabetes, and we know that it also can impact how we metabolize our food. 

[00:24:31] Tim Spector: It could be acting through sugar peaks, for example, just in a very simple way. One of those methods is that if you get inflammation, your sugar, peaks are going to be bigger, then you start to gain weight, that could be one mechanism. 

[00:24:43] Sarah Berry: Yeah, there's bi-directionality, for sure. We know very clearly the evidence for, obesity or weight gain influencing inflammation. The other direction, I think, is something that we need to spend more time focusing on. It had always been assumed it was one, one direction, but as we see with most food disease-related pathways, there's always two... 

[00:25:08] Tim Spector: Two sides to every story, yes. 

[00:25:10] Jonathan Wolf: So as well as weight gain, we had a lot of questions around two other things, menopause, and aging. So maybe we can sort of touch on those before talking about, okay, what I'm sure most listeners are really interested which is what can I do to reduce my dietary inflammation? So what's happening to inflammation during menopause. And then if we think about aging more broadly, Tim, you touched right on the beginning, that inflammation seems to be very linked to it. Can we sort of cover those two topics? 

[00:25:36] Tim Spector: Should I start with aging? So as we get older, our immune system changes, and, our microbiome also changes and the two are very closely linked so that most of our immune cells are actually in the gut lining. 70% of them. And of course, our microbiome is mainly in the lower part of the intestine, in the colon. So they're interacting all the time. Our immune cells are changing the age and, our microbiome starts to change really subtly, but quickly, once you get into your 70s. And I think what we're looking at with aging is, a, balancing of these anti-inflammatory responses. That's crucial to just getting enough so that your immune system can attack invaders, stop infections and stop cancer.

So interestingly, this whole system is also related to the ability of your immune system to recognize cancers and pick them off early and not overreacting and giving you auto immune disease and other things. And I think the ability to react as you get older, starts to wane and that fine tuning that's going on all the time, you know, constantly your body is trying to work out, do I attack this? Do I let it go? Is this food protein good? You know, how much investment energy in fighting, whatever it is, starts to go a bit wrong. And we've seen this and once that happens, you just get this imbalance and you start to get less control of inflammation for things that should normally cause it, wouldn't have caused it 20 years before. So that's why you get more inflammation with things like foods as we've talked about or minor traumas. And this has been linked very clearly to a risk of not only cancers, heart disease, but also dementia. All of these are part of this immune regulating system that is stopping minor injuries, but also getting rid of these waste products we talked about earlier, these free radicals, the sparks of you, like and metabolism, start to accumulate. This also leads to more inflammation. So it's just a great system. Just wasn't built, you know, to live for 80 years, it was, you know, you're out of warranty at that time. And that's what really, what seems to happen. And these things start to go wrong. And that's really the unifying reason why our immune system and our microbiome are so crucial in the aging process, and the more we can keep our immune system along the right lines, via our food in our microbiome the more we can prevent rapid aging and all these other problems.

[00:28:22] Sarah Berry: And, Jonathan there are some lovely studies that have been published RCTs (randomized controlled trials), and a high number of them, that quite consistently show that if you can increase bioactive, such as polyphenols in people's diet, you can somewhat reduce some of the cognitive declines, so you can improve their memory, their brain responses.

And this is from supplement studies as well as whole food studies. And I think when the researchers have looked at some of the mechanisms behind this, it quite clearly shows that there's one of the mechanisms is this inflammatory response that's reducing some of the inflammation over a period of time and therefore is attenuating it. And so hence the association as well with food and dementia, because of some of these inflammatory pathways. 

[00:29:12] Jonathan Wolf: So we've talked about a lot of things that can happen that are bad. And we always like to say, well, you know, what can you do about it? So, what can our listeners do to reduce their dietary inflammation? And I had a lot of questions asking about specific foods so, dairy nightshade, vegetables, and even tea as things that cause inflammation. And should they be cut out? I also had a great question saying, are there any super hacks for inflammation example was, you know, like sprouting peas in the dark for histamine that we had on another podcast with, Will, so, you know, other than of course doing like a full ZOE test, what should people do about this?

[00:29:52] Sarah Berry: I don't think there's any magic bullet with inflammation. And I think this is the problem where, and these anti-inflammatory diets have verged into this whole arena of a pseudoscience because you know, people are saying, oh, eat one goji berry a day and you will live forever. And, you know, look 20 years younger because it's anti-inflammatory, I think that there is robust evidence for some foods, having anti-inflammatory properties. There is robust evidence that some foods are more pro-inflammatory, but I think the kind of wealth that the evidence points to us considering our dietary patterns, so considering not just individual foods, but our overall dietary habits, as well as our overall dietary patterns. And, there's an index called the dietary inflammatory index, which brings together thousands and thousands of studies, including a lot of randomized controlled clinical trials, and has come up with 45 components where there's robust evidence that they have either a pro or an anti-inflammatory effect, and these consist of particular foods.

So these would be foods such as garlic, ginger, or any fish, for example, nuts, and seeds. And, it will also consist of nutrients where we know, for example, there's good evidence that omega-3, we can pick up on this. 

[00:31:12] Jonathan Wolf: These are the good ones or the bad ones? Just to understand. 

[00:31:15] Sarah Berry: Good, so these are the anti-inflammatory, so, such as omega-3 and omega-6, and omega-6 might surprise some people, we can pick up on that, but also lots of bioactive. So lots of the kinds of compounds, such as polyphenols that we've mentioned, but a lot of compounds that are in herbs and spices as well. 

[00:31:36] Tim Spector: Can I simplify that message? Because I think in modern science, we've moved away from this reductionist idea of picking a few ingredients of these things and seeing that was in a laboratory that's anti-inflammatory or it's pro-inflammatory.

And I think what I saw in my research is that basically everything that has these phytonutrients, these polyphenols that are food for our gut microbes, and they're made of pole plants. And they've got some fiber, tend to be anti-inflammatory and stuff that is ultra processed that, contains artificial chemicals, junk food, is processed. So it's actually much simpler than trying to work out which particular ingredient because we're talking about hundreds of components in each of these. And I think generally things that are good for your gut microbes tend to be anti-inflammatory and things we know are bad, are bad. And we're just skimming the surface of the reasons why, but I think I don't want people to get into the idea, they've got to look up a whole list of foods to say this is good or bad. And when I was treating patients with rheumatoid arthritis, I was a rheumatologist who used to have many patients, who would never eat tomatoes because they were told that these are particularly bad for inflammation. And there is absolutely no evidence for that at all.

And if you eat a diverse range of plants, particularly vegetables, that's going to be an anti-inflammatory diet, per se. I'd really have to look at it in great detail and all these other stories, as you mentioned, are probably false now, you know, they're done on very small numbers or outdated methods and techniques. So I think we need to be much broader, and more holistic, in the advice we are trying to give people.

[00:33:26] Jonathan Wolf: And what about excluding things, Sarah? So I think we had a lot of questions around this and Tim gave an example, right? With tomatoes and saying, well, I'm worried about inflammation, so I'm worried about there being various foods, which are inflammatory. And I think here, we're talking about whole foods. We're not talking about the ultra-processed foods that you were talking about. Is there a set of foods that people should be giving up in order to reduce their inflammation?

[00:33:51] Sarah Berry: So I don't think that anyone should ever give up any foods that they enjoy. I think that they should think carefully about how they balance the foods within their diet. I think that there's good evidence around processed foods, as you've said, but in terms of individual foods being particularly harmful, I'm not aware of any that there's robust evidence around if consumed in moderation as part of a healthy diet. I mean, you know, excess alcohol. Yes. We know that in excess that's particularly bad for inflammation but Tim, unless, you know, of any particular. 

[00:34:27] Tim Spector: There's some evidence that nitrate-containing foods, which often they're usually processed, but it's quite complicated because nitrates are actually anti-inflammatory and nitrites are potentially proinflammatory. 

[00:34:42] Jonathan Wolf: I can see that could get me in trouble. Such subtle distinctions. That means everything. 

[00:34:47] Tim Spector: Yeah. It's very complicated and it's not all the same. And so there's been a lot of misunderstanding that, anything with an N word in it is seen as, you know, deadly, you have to avoid it. And, a lot of plants and vegetables contain lots of good nitrates. They get converted by microbes and nitrites and different amounts in people. But I think we shouldn't have foods to avoid because we shouldn't be eating that much of that food anyway. And if you did eat it, it's one of those 30 plants you should be having a week. So it's not, even if it was not at least neutral or slightly bad for you, it would be overwhelmed by all the other foods, as long as you've got that diversity on your plate.

And I think that's probably the big message and we've got to know much more about these foods in the next 10, 20 years than we do now. We have very primitive knowledge. So I think we've come a long way in the last few years, but we still don't understand, you know, the 600 chemicals that are in the average plant and what they do to our bodies.

But generally, you know, we know they're good and that's what we should be supporting. 

[00:35:49] Sarah Berry: And I think going back to a point I made earlier plants are designed to protect themselves, not just us. So if we think of vegetable oils, as an example, the more polyunsaturated fatty acids there are in vegetable oil, which we know are more prone to oxidation, which therefore might increase inflammation in our bodies, but oxidation within the plant, the more polyunsaturated fatty acids there are, the more antioxidant compounds there are in the oil. And so if you have a very polyunsaturated fat-rich oil, it has more vitamin E often or more polyphenols. Yet when you have an oil, that's very rich in monounsaturated fatty acids, which is less prone to oxidation, it has a lot less of these antioxidant compounds. So the plants themselves inherently actually have their own defense mechanism to look after this oxidation, which when we consume is what causes some of this inflammation in us. 

[00:36:46] Tim Spector: Which is the sponge, just as a simple term. This is these chemicals, which just sponge up the damage due to our everyday metabolism.

And that's what we call an antioxidant, which I think is a bit of an outdated term, but we haven't found a better one at the moment. 

[00:37:01] Jonathan Wolf: Brilliant. Well, I think we are sadly at time and I have so many follow-up questions as always. I think if we sort of look back over the podcast, I think we started by saying that information is normal. And that's really important. And that actually to have short bursts of inflammation is indeed good and required to keep us alive. So it's a sort of this prolonged long-term inflammation is bad and it's a problem that you then said is linked to long-term, diseases linked to weight gain. Then said that dietary inflammation is real. So the food we eat actually really can affect our inflammation. That the microbiome seems to play a very important role in this. That menopause is a period where we see huge changes in inflammatory levels, sort of before, during, and afterward. And the microbiome is also changing there as well. And that then as we think about, aging in general, the immune system is very involved. It's degrading.

And then at the end, I think we said sort of what can you do? And Sarah, I think you said there's no magic pill. There's no, unfortunately, super food that we can just eat to solve all of this. But that in general, I think talked a lot about polyphenols, which are all these different chemicals in plants that there's some evidence that this can actually improve brain function.

As we're thinking about aging, in general, ultra processed foods tend to be bad for inflammation. But then when we're thinking about other foods critically, don't think about cutting foods out. There's not a whole set of sort of inflammatory foods, normal foods that you should cut out. So it's more about, I think Tim was pushing hard, you know, a diverse diet and Sarah, I think you've taught, I caught fruit, vegetables, oily fish, you know, nuts, are things that in this, sort of anti-inflammatory diet come out, particularly strong.

Brilliant. Thank you both. 

[00:38:51] Sarah Berry: Thank you. 

[00:38:51] Tim Spector: Thank you. 

[00:38:53] Jonathan Wolf: Thank you to Sarah and Tim for joining me on ZOE science and nutrition today, we hope you enjoy today's episode. If you did, please be sure to subscribe and leave us a review. As we love reading your feedback. If this episode left you with any questions, please send them in on Instagram or Facebook.

And we will try to answer them in a future episode. At ZOE we want to improve the health of millions of people around the world by starting with an at-home test and then using the latest science to identify the right foods for your body. If you're interested in learning more about ZOE. You can head to join ZOE.com/podcast and get 10% off your personalized nutrition program.

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