ZOE Science & Nutrition - Hidden health risk? The truth about emulsifiers with Dr. Federica Amati

Episode Date: July 11, 2024

Emulsifiers are common in our diets, enhancing the texture, appearance and shelf life of many foods. But are they safe? In today’s episode, Jonathan and Federica uncover the surprising truth about emulsifiers in our food. We learn the science behind emulsifiers, their impact on health, and the rising concerns over there extensive use in ultra-processed foods. Dr Federica Amati is a King’s College London researcher and a registered nutritionist. She is also a lecturer and Nutrition Topic Lead at Imperial College School of Medicine. Federica empowers people with accessible, practical knowledge to make informed choices on diet and lifestyle and to improve health based on unique needs and preferences, at every stage of life. Learn how your body responds to food 👉 zoe.com/podcast for 10% off 🌱 Try our new plant based wholefood supplement - Daily 30 *Naturally high in copper which contributes to normal energy yielding metabolism and the normal function of the immune system Follow ZOE on Instagram. Timecodes 00:00 Introduction 01:10 What are emulsifiers doing in our food? 02:15 How common are emulsifiers in our food? 02:52 What to look out for on packaging 03:55 What are emulsifiers made from? 04:36 How emulsifiers work 09:50 Are emulsifiers bad for us? 10:40 Emulsifiers and our gut health 11:50 New risks emerging from human studies 14:50 How to reduce emulsifiers in your diet Buy Federica’s book: Every Body Should Know This  Free resources from ZOE: Live Healthier: Top 10 Tips From ZOE Science & Nutrition  Gut Guide - for a healthier microbiome in weeks Mentioned in today’s episode: Food additive emulsifiers: a review of their role in foods, Nutrition Reviews  Emulsifiers Impact Colonic Length in Mice and Emulsifier Restriction is Feasible in People with Crohn’s Disease, Nutrients 2020 Food Additive Emulsifiers and Their Impact on Gut Microbiome, Permeability, and Inflammation, Journal of Crohn's and Colitis Bacterial Overgrowth and Inflammation of Small Intestine After Carboxymethylcellulose Ingestion in Genetically Susceptible Mice, Inflammatory Bowel Diseases Have feedback or a topic you'd like us to cover? Let us know here. Episode transcripts are available here.

Hello, and welcome to Zoe Shorts, the bite-sized podcast where we discuss one topic around science and nutrition. I'm Jonathan Wolfe, and today I'm joined by Dr. Federica Amati, and today's subject is emulsifiers in food. Federica, I'll be honest here, I thought emulsifiers were a type of paint. Yeah, so we're not talking about paint today, Jonathan. You might not know exactly what emulsifiers are, but you'll definitely have eaten them without knowing. Emulsifiers are present in a lot of food products these days. So why are emulsifiers in our food?

And more importantly, are they safe? In this episode, Jonathan, we'll find out what the science says. Great. Let's dive into the murky world of emulsifiers. So Federica, I want to make a quick introduction for listeners who don't know you yet. You're a lecturer at Imperial College London, a researcher at King's College London, and the author of the bestselling book, Everybody Should Know This. And we're also fortunate enough to have you as our head nutritionist here at Zoe. And I know you spent a lot of time thinking about this topic. So let's take a step back because I'm sure I'm not the only one wondering

what is an emulsifier and what is it doing in my food? Thanks, Jonathan. Yes, so in simple terms, emulsifiers combine substances or liquids into creamy emulsions. So if you imagine a jar of mayonnaise, the emulsifier is what stops the oil from separating from the vinegar. Or if you've ever made your own salad dressing at home by adding olive oil, vinegar, and a little bit of mustard, you'll know that at the start, they're all separate entities with the oil sitting at the top, but then you shake it

and it completely transforms into one creamy consistency. This is because in that case, mustard is acting as an emulsifier. Ah, so emulsifiers help mix different things together that normally don't mix. Exactly. So they keep the different components stable and they also help foods to feel smoother and less sticky when you eat them. So emulsifiers are extremely widespread now. You'll come across them on lots of different ingredients labels. They're key in improving the appearance, texture, and shelf life of many common industrial foods.

But they are also found in some natural foods, like in eggs or in soy, for example. So just how widespread are they now? Well, a 2019 review found emulsifiers in most foods consumed in the US. The US food emulsifiers market was valued at $817 million in 2022. And that number is set to increase as the demand for convenience food continues to increase. In the UK, as of last year, emulsifiers are present in more than half of all ultra-processed foods, including 95% of pastries, buns and cakes, ice creams and yogurts, and almost 80% of confectionery. Wow. So they're basically everywhere.

So Federica, help me to walk through this. Let's imagine I'm doing my weekly grocery shop. I'm browsing the grocery store aisles. What should I be on the lookout for on packaging? So let's say you've picked up a sandwich. The filling might contain an emulsifier called guar gum. A sandwich spread could have something called xanthan gum in it, or you might pop some cereal in your basket and that might have sterile lactolates. Even the bar of chocolate you throw in at the till, that likely contains desiccant.

Those are all different names, but they're all different types of emulsifier. That's right. None of which sound very appetizing. Yeah, indeed. I mean, in the US, the Food and Drug Administration has approved 171 emulsifiers for human consumption, or they also have emulsifying salts. Here in the UK, the Food Standards Agency has been a bit more stringent. There's only 63 approved emulsifiers, including other agents like stabilizers, gelling gels, gelling agents, and thickeners. And so what are emulsifiers actually made from?

Typically, they're made from plant or animal-based sources or from synthetic chemicals. So lecithin, for example, is the one that's in chocolate and it can be sourced from soybeans or eggs, liver, peanuts and wheat germ. So I could make these in my kitchen? No, absolutely not. So they're very much industrial ones that we've mentioned and they require complex chemical processes,

which is why you don't use them in your kitchen. And what about the wonderfully named xanthan gum? Great name, very futuristic, isn't it? But it's actually a synthetic emulsifier. So it's made by bacterial fermentation where the microbes break down glucose and make xanthan gum as a byproduct. I'd like to try and understand a bit more

about how these emulsifiers work. How are they functioning in this food that I'm buying at the grocery store? So I think the best way to think about it is if we picture a food like bread. If you've baked bread at home with simple ingredients, maybe you were perfecting your sourdough recipe, Jonathan, during the lockdown, then you'll know that it's very tasty, but you probably need to eat the whole loaf in a couple of days if you want to enjoy that fresh dairy texture. I'd like to share something exciting.

Back in March 2022, we started this podcast to uncover how the latest research can help us live longer and healthier lives. We've spoken to leading scientists around the world doing amazing research. And across hundreds of hours of conversations, they've revealed key insights that can help you to improve your health. If you don't have hundreds of hours to spare, no need to worry. At the request of many of you,

our team has created a guide that contains 10 of the most impactful discoveries from the podcast that you can apply to your life. And you can get it for free. Simply go to zoe.com slash free guide, or click the link in the show notes and do let me know what you think of it. Okay, back to the show. Well, Federico, as you know, my Zoe app is very clear that bread and my terrible blood sugar control don't get on very well. So bread making has not been a big thing for me in the last few years, but I am definitely aware that like a freshly baked loaf of bread goes stale pretty quickly. Exactly right. So let's compare that to your typical loaf of bread from the supermarket, your pre-sliced loaf. The emulsifiers in that bread,

like diacetyltartaric acid esters and mono- and diglycerides of fatty acids, which really rolls off the tongue, that results in a softer bread with a much longer shelf life. So what about my beloved bar of dark chocolate? Are you going to tell me that that has emulsifiers in it as well? Yeah, so chocolate products tend to contain lecithin or ammonium phosphatide, but quality is important here. We use emulsifiers in chocolate so that they can be molded into bars. It's all about getting that consistency.

And how about ice cream? So ice cream. Emulsifiers like polysorbates are added during the freezing process, which results in that very smooth texture and also helps to make sure that when you have a bottle of ice cream, it doesn't just melt too quickly after you've served it up. One of my favorite examples actually is nut butters. So those with added emulsifiers are always really creamy in consistency throughout the whole pot, whereas those without tend to separate. So you need to stir them as the oil will sit on the top and the bottom will be a much drier, thicker consistency. This is actually also the same

for yogurts, Jonathan. When you add emulsifiers, they stay creamy throughout the whole pot, but a natural yogurt will separate in the fridge. Got it. So it's one of the ways you could tell this was like really, really natural yogurt is actually going to have a sort of layering to it, Federica, which is not, I have to say, the experience of almost any yogurt I've ever bought. So if you get like a natural Greek yogurt, Jonathan, or a natural yogurt,

the Greek yogurts are more obvious. They have this sort of watery layer at the top that collects at the top of the yogurt, and then you stir that back in. That's perfectly normal, and it just means that they haven't added emulsifiers to maintain that creamy consistency throughout got it and we are so used to like the things that we buy from the store with emulsifier we just assume that everything should be mixed together and that if in any way it's

separated it's it's a bit weird and maybe you shouldn't eat it yeah it's funny i mean there's no reason why they shouldn't separate. It's just purely aesthetic. And because we're used to having this consistent creaminess in our products. So I don't know if you've ever bought the big tubs of nut butter. You know, you've really got to mix them up because they do separate.

And it's exactly the same with the Greek yogurts, the natural yogurts. You open them up, there's this watery layer at the top, but that's a perfectly normal part of the yogurt. Just mix it, stir it back in, and then you're good to go. It's amazing. I think about my mother-in-law's salad dressing. She makes this wonderful salad dressing, and you have to shake it because if it sits in the fridge, you take it out, you've got to shake it because otherwise it's separated. But you're right. I'm used to the fact that anything else I buy, you never need to do anything. That's fascinating.

So it sounds like these emulsifiers have some great functions for food manufacturers, right? Wanting to make these products smooth and all the rest of it. And they're also incredibly common, especially in ultra-processed foods. So Federica, how much of this stuff are we now consuming in our diets? And how much should we be eating? So you can imagine that measuring how many emulsifiers people eat on average is really tricky, actually. And is that because we all eat different amounts of different foods?

That's right. And it's really hard to know exactly how much emulsifier there is in a given food item. We don't actually get the number or the amount that's put in there. So let me guess. This is because the amount of emulsifier in foods is not properly recorded. And that's because government, you know, dietary advice has previously focused on macronutrients, like, you know, the amount of carbs and fats, the number of calories. So you've got to record that really accurately and give it to a government body. But you don't need to record how many emulsifiers and how much there is in your food and give it to anybody. Exactly right. So these non-nutritive components, which don't account

for calories or macronutrients or like vitamins, there's no sort of exact recording of how much of that is in our food. But nowadays, so many of our foods contain these added chemicals that we're starting to actually care about how much of our diet actually is made up of these chemicals. And has there been any research looking at how much we're consuming? There has been, and there's more research coming out now because it's of interest. So one study really looked at the intake of some additives, including emulsifiers, in the UK, France, and Ireland. And it found that children and adults did actually exceed

what's called the acceptable daily intake of some emulsifiers. So exceeding the acceptable intake sounds pretty bad, Federica. It does. But then on the other hand, some US research looked at the intake of seven specific emulsifiers, and it concluded that most people didn't go over the acceptable daily intake. And I guess this raises the question of what the acceptable daily intake is, and also, I guess, why the acceptable daily intake might be higher in the US than it might be in France. Exactly. So I think that brings us to the billion dollar question, Federica.

Are these emulsifiers bad for us? Right. So before we jump into the research, there's a couple of very important caveats. The first is that most of the research we have on emulsifiers to date on the mechanism in which they work do come from animal studies. And so we can't assume that the results would apply to us because, you know, we're not mice, we're human beings. Exactly. So that's a really important point to remember. The other is that scientists have only looked at one emulsifier at a time typically, and they haven't examined the effects of consuming a cocktail of emulsifiers at once, which is actually how most of us consume them. I love that idea of a cocktail of emulsifiers, which does not sound as nice as the alternative cocktails that you might be offered.

So I guess that means we're taking the following research with a big grain of salt? Exactly right. And there have been several studies on mice, which showed that common emulsifiers do impact the health of their gut microbiome. And how do they affect the mice microbiome? So they appear to cause an imbalance in the gut microbes and this promotes metabolic syndrome and inflammation. Now let's go back to our example of the mayonnaise or when you shake your lovely dressing. If you imagine that our gut

biome has layers, so our gut microbes make things like short chain fatty acids which are fatty, but then we also have like a water loving layer in the gut you can imagine how if we eat a lot of these emulsifiers it kind of messes up that balance that separation of fatty layer and water layer which we actually want to maintain in the gut microbiome so when you think about that then these mouse studies start to make a bit of sense another mouse study concluded that the emulsifier carboxymethylcellulose, which is often seen as CMC on food packaging and is really ubiquitous, is an ideal suspect to account for the rise of irritable bowel syndrome in the 20th century. Wow. And ubiquitous is science speak for everywhere, yes? Yes.

That doesn't sound good. Have there been any human studies at this point? So yes, human studies tend to be observational so far. So we can't assume causation because it's really observing people in their messy lives and trying to understand how much is attributable to emulsifiers versus other things. But there is emerging science that points to potential disruption for the gut microbiome. And so emulsifiers have been recognized by the European Food Safety Authority as an emerging risk, which is quite serious, actually. In 2017, there was a small randomized control trial in humans looking at the effect of emulsifiers carrageenan, in this case, on patients who have ulcerative colitis, Jonathan, which is a type of irritable bowel disease. And it concluded that carrageenan intake increases the likelihood of ulcerative

colitis relapse, which is really quite serious. Another study tested mice and humans with Crohn's disease, another IBD, and at the end of a low emulsifier diet, they had fewer IBD symptoms. Wow. So Federico, it sounds like there is some preliminary research that may signal a warning. But from where we stand right now, we don't really have strong scientific studies in human beings on the impact of emulsifiers yet. Yes, that's true, Jonathan. So we do know that emulsifiers play important roles in our food and that they're very widely used, especially in ultra-processed foods. The data we do have points to a negative impact on our health overall. Take the results from the

NutriNet-Sante study that found emulsifiers in the diet were associated with a higher risk of cardiovascular disease when analyzing data from over 90,000 people, which is a lot. So I'll be honest, I do find all of this a bit terrifying. You know, you sort of explained that emulsifiers are not a natural part of our diet. They're not something that you can make in the kitchen. It's therefore not something that we've ever sort of evolved to be exposed to in the sort of scale that we're seeing. And yet they're in most foods in the US now and an ever increasing fraction of foods in the rest of the world. And I know that, you know, from other podcasts we've done, that ultra processed food is particularly high in the

food that we give to our children, for example, and therefore I assume particularly high in these emulsifiers. So it sounds like we should be doing a lot more studies and really understanding what we're doing. Yes. And it's really about understanding these artificially added emulsifiers. As we mentioned at the beginning, some natural foods like eggs contain them, but they are part of a much more nutritious package, right? And there is increasing evidence that ultra-processed food is really bad for us. What role emulsifiers play in this versus other additives like artificial sweeteners is unclear. Since we only have animal studies showing a direct effect, a lot more research is needed. We simply don't yet know exactly how they impact gut and metabolic health in humans, though as we said the signs really

aren't positive. And we definitely don't know how they work together with each other and with the other additives in ultra-processed foods. So what can people listening take away from all of this? So Jonathan, as you know, I always like to remember that we eat food and not individual components of food or chemicals. So these emulsifiers are mostly found in pre-packaged, industrially made foods. I think the message for anyone who is listening and potentially worried about the effects of emulsifiers, especially if they suffer with IBS or IBD, is to find where you can reduce eating ultra-processed foods in your day. So reducing your intake of ultra-processed foods generally will lead to cutting down on your intake of emulsifiers

as well as other additives and make space for food that is better for you. Hi, I have a small favour 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. I find that this is an example of something that I'd literally never even heard of seven years ago, and that even three or four years ago, I wasn't worrying very much about.

And I feel that I'm worried more about it talking to you and the many other scientists who are closely involved at Zoe. And one part of that, I think, comes from being much more aware of this idea that my gut health is important, that all of these different bacteria in my gut are sort of helping me out, that my gut health is pretty miserable compared to the gut health of somebody who didn't grow up in the West and have, you know, 15 courses of antibiotics by the time I was 10. And that in particular, there seems to be some of these scientific studies showing emulsifiers sort of interacting with your gut microbiome in ways that we don't understand.

I don't think that if I eat a little bit, it's going to sort of kill me. But I'm definitely thinking a lot more about trying to avoid foods that are stuff full of this and probably see a lot of foods that I might buy in the grocery store that I would have thought of before as healthy. Now feeling like I'm not really sure that this is as good as it looks like it is. Yeah. So I think always remembering that our gut microbiome is very resilient. So if we've had a few years or maybe we've had a diet up to this point where there's been a lot of convenience foods, maybe we're time poor. And actually, I think for the majority of us, we just weren't even aware of just how many ultra-processed foods had made their way into our baskets.

Identifying emulsifiers is a nice way to sort of raise a red flag. So if a food contains like four different emulsifiers and maybe some artificial sweetness, and there's lots of ingredients that you just wouldn't have in your kitchen, then think about whether that specific food, could you replace it with something else in your chopping basket? So it may be the simplest example is the Greek yogurt, right? Instead of buying the flavored strawberry low-fat yogurt, could you just buy the Greek yogurt and then go home and blend it up with some frozen berries yourself if that's

what you want to have, some flavored yogurt? Or could you just simply be more aware of how easily these foods have made it into your day and could you reduce them i think our gut microbiome every day we have an opportunity to renew the top layer that are there waiting ready to make lots of helpful postbiotic chemicals for us these wonderful mini pharmacies as tim calls them you know maybe we can just think about how can we feed tomorrow's microbiome a little bit better? So what can we change today to help them not get emulsified, to help them not get shaken up by lots of emulsifiers, and actually give them plenty of fiber to eat, plenty of whole foods to break down and try to reduce these, as I said, these

non-nutritive chemicals that we thought did nothing, but actually they really do impact our gut microbes. They're at the receiving end of it, at the bottom of our colon. So just try to reduce what we're giving our microbiome to deal with, I think. I love the idea that, you know, at any point you can start to turn things around with your microbiome. It's one of the things I think that's incredibly positive. As you're describing this, like picking the yogurt that isn't full of emulsifiers versus the one that is, it made me think about an experience I often have when I'm abroad. So, you know, when I'm at home, it's very easy. You know, I use my Zoe app. It just tells me like, for me, the score of any of these foods. And I know that I can eat these things. I don't need to think about it. When I'm abroad and I can't use my Zoe app to scan a food, I increasingly,

you know, turn it over, look at the food label when I'm buying something. When you're abroad, often you don't really know exactly what food you're used to getting. You're trying to find like, is this a natural yogurt or something completely different? And if I see two products, one of which has an emulsifier in it and the other doesn't, I now immediately buy the product without the emulsifier because my mind is like a sort of shortcut to avoiding ultra processed food and helping support my gut microbiome, which needs all the help it can get. Is that, you know, how do you think about that as I share that, Federica? I think that's a really good idea.

It's actually really funny because I have a similar experience with yogurt where it says like natural and then you turn it over and you're like, oh, natural, not at all. Actually, loads of sweeteners, loads of emulsifiers. I think the one important point here, Jonathan, is also sometimes it's easy to switch things up. So it's easy to buy a natural Greek yogurt instead of a natural one that has emulsifiers in. But a lot of people are getting quite worried about things like emulsifiers in plant-based milks, for example. And we have to be mindful that if you're having a splash of oat milk, for example, in your coffee, it's a relatively little tiny amount of food compared to what

you're eating in the rest of the day. So what we want to avoid is for people to feel really stressed out by this information. And it's really about focusing on the foods that we eat more of, for example, your yogurt. I know that you love a yogurt bowl in the morning. So if you're eating a yogurt bowl in the morning every day, and it eating a yogurt bowl in the morning every day and it's a good amount of yogurt, then you definitely want to try and opt for yogurt that isn't full of emulsifiers and it's quite easy to find. But if you're someone who's navigating

buying non-dairy milks and you find that there is an oat milk or a soy milk that has like one emulsifier listed on the packaging, then I would encourage people not to stress too much about that because it's a relatively smaller amount of that food that you're going to get throughout the day. listed on the packaging, then I would encourage people not to stress too much about that because it's a relatively smaller amount of that food that you're going to get throughout the day. So definitely use it as like a way to distinguish foods, but also be mindful of like what quantity

of that food will you be eating? And is it easy for you to find alternatives? I guess your message here is you're not saying that the evidence suggests that we're going to suddenly discover that emulsifiers give us cancer or something like that. You're saying that it looks increasingly like these are not really a healthy part of your diet, that they are hiding in a lot of things. And so a bit like when we talk about foods that maybe you're intolerant to, there's an amount effect. So like a very small amount of emulsifier, you saying is, it's probably not something I need to worry so much, but if I realize, you know, as I think I realized with my children that like 80% of their diet is, is actually this ultra processed food. This is all layering on top and you'd really like to, to reduce this. Yes. It's like the 80-20 rule. So if we can get 80%, the majority of our diet

in a really good place, then there's space for the 20% where perhaps you just really love the taste of something in your coffee. I keep going back to this example because it's the one I get asked about the most. And actually, for that purpose, keeping to that milk is okay. But if your bread and your yogurt and maybe your pizza base that you're making with your kids, and even dressing, salad dressings. We want people to eat more salad and enjoy their greens. But if you're doing that every day,

like make your own at home would really help to reduce your intake. So exactly, Jonathan, there is a dose effect. So it's about reducing and not becoming anxious about completely eliminating. I think that's the message. And I think your example around the sort of oat milk is really interesting. I think it's a great example because you were describing how emulsifiers are used by lots of food manufacturers in order to make a product in a particular way, which it might not naturally be. I know what oats look like because they're like a solid thing that comes out of a plant that sort of sits in a packet downstairs

so I guess it's not surprising if you want to turn them into a milk you're going to have to do something which is in fact not like a normal thing that you're just going to do you know they just naturally do that so you're almost bound to have to to use something like that in order to you know make a food from one thing into this other way of consuming exactly and the different brands have different levels as well so some brands just add a little bit of um rapeseed oil actually as an so relatively natural emulsifier whereas others will have four or five emulsifiers plus added sugar plus artificial sweetness so there's also like a sliding scale there of what you can choose but exactly to your point like we there are people

who make their own nut milks and their own oat milks which is great but they will naturally separate in the fridge and most of us as consumers want to buy something that we can add to our drinks or to our cereals or to whatever we're eating in a way that's quite similar to cow's milk right because that's what we're trying to replicate so it's just being mindful of the variety of quality that there is and then of what to focus on so if you're having a splash of oat milk in your coffee or soy milk in your coffee that's maybe the last thing to change compared to the rest of your diet which is a lot more food a lot more components to think about and I'm always careful with these messages of not adding extra anxiety for people who may already

find navigating the food environment quite tricky so So I think it's a really useful context, but just making sure that we focus on the things that we can change and that will have the biggest impact. Absolutely. And as you're thinking about it, I'm thinking, well, that's exactly why we have the Zoe app that can just instantly tell you the difference between the scores for you of these different oat milks, because yes, I have actually seen that, that there's this huge variety, right, about how much actual sugar there's in and all the rest of it. So it's a brilliant example. Thank you so much, Federica.

Now, if you've listened to today's podcast and you'd like to reduce the muscle fires in your life and take the first step towards more energy, less hunger, and more healthy years, take our quiz to unlock new food choices you could be making right now. Simply go to zoe.com slash podcast, where as a podcast listener, you can also get 10% off. I'm Jonathan Wolfe. And I'm Federica Amati. Join us next week for another Zoe podcast. Bye.