ZOE Science & Nutrition - Recap: This type of daily chocolate could improve gut health | Spencer Hyman and Prof Sarah Berry

Episode Date: September 23, 2025

Today, we’re unwrapping the truth about chocolate. For many of us, chocolate is a guilty pleasure. But what if I told you that you didn’t need to feel guilty? Because it turns out that not all chocolate is created equal. And by changing the type of chocolate you eat, you can support your health instead of harming it. In this episode, I’m joined by chocolate expert Spencer Hyman and Sarah Berry to show you how to enjoy chocolate with a clear conscience. 🌱 Try our new plant based wholefood supplement - Daily30+ *Naturally high in copper which contributes to normal energy yielding metabolism and the normal function of the immune system 📚 Books from our ZOE Scientists: The Food For Life Cookbook by Prof. Tim Spector Food For Life by Prof. Tim Spector Every Body Should Know This by Dr Federica Amati Free resources from ZOE: Live Healthier: Top 10 Tips From ZOE Science & Nutrition  Gut Guide - for a healthier microbiome in weeks Have feedback or a topic you'd like us to cover? Let us know here Listen to the full episode here

Hello and welcome to Zoe Recap, where each week we find the best bits from one of our podcast episodes to help you improve your health. Today we're unwrapping the truth about chocolate. For many of us, chocolate's a guilty pleasure. But what if I told you you didn't need to feel guilty? Because it turns out that not all chocolate is created equal. And by changing the type of chocolate you eat, you could support your health instead of harming it. In this episode, I'm joined by chocolate expert Spencer Heimann and Professor Sarah Berry to show you how to enjoy chocolate with a clear conscience. The cocoa bean, which grows in a pod on trees in the rainforest, is initially a very bitter and astringent seed,

which through the magic of fermentation, becomes a rather interesting bean, which is then generally roasted for good chocolate, and then it's winnowed, which means you take the shell off it, and then it's ground, and then it's conched, and then it's tempered, and a little bit of sugar is sometimes added to it, maybe a bit of milk is sometimes added to it as well, and then it's turned into bars. That is the way that good chocolate is made, but there is an alternative process, too. And what's the difference between a dark chocolate, a white chocolate, you know, milk chocolate, and these different percentages that I think we see a lot more on the grocery stores than

when I was a kid, you know, saying 50% or 70% or whatever. Yeah. So I think there's been a move to basically use sugar more as a flavoring enhancer in the way that, for example, you'd use salt with dark craft chocolate. And the big difference between the three products that you've outlined, I'm just talking about craft chocolate, not industrially processed chocolate here, is basically the other inclusions that are put in there. So milk chocolate is basically cocoa beans, a bit of sugar.

and a bit of milk powder. White chocolate, which was originally sold as a vitamin supplement in the 1920s in Switzerland, which is another whole story, is just basically cocoa butter, often with a lot of milk powder, some sugar, and sometimes other flavourings, often vanilla. And is cocoa butter different from chocolate that you just mentioned? So what happens when you take a cocoa bean, and maybe we could dive into the two big differences in how you make chocolate,

inside a cocoa bean is basically about 50, 55% cocoa butter. which is the secret ingredient to lots of cosmetics, and then what's called cocoa mass or cocoa solids. And when you make a white chocolate, you just use the cocoa butter. And the big thing about chocolate is that everybody assumes that all chocolate is created equal. And it's not quite that simple. Because if you just take a bean, and as I said, you roast it, and then you winnow it, and then you grind it,

you can get all the wonderful flavors, you can get all the wonderful benefits, that cocoa's got inside it like therobroming, which I'm sure Sarah's going to talk more about in a sec, all the flabinolts and everything like that. But there's an alternative way, which is basically used to make cocoa butter for cosmetics, which is you take the bean, you will generally take the shell off it before you roast it.

You'll roast it at very high temperatures, and then you will often squeeze it in massive hydraulic presses. And those hydraulic presses basically squeeze out the cocoa butter and leave behind a cake. And the cake is often washed in an alkaline solution, because that makes it less acidic and a little bit less bitter, and also it changes the colour so that it's a bit more attractive. And if you have most sort of chocolate biscuits or most chocolate cakes

or lots of chocolate confectionery, it will be made in that way. And it is very likely that a lot of those steps damage some of the wonderful benefits that chocolate has inside it. And I always think it sounds crazy to say there could be any health benefits from chocolate because it's sort of obvious. It's like a sweet, right? It's like a candy. obviously it can't actually be doing anything good for me, can it?

So you're making me think of that saying if it's too good to be true, is it true? And I think going back to what Spencer said earlier is chocolate is so diverse. To group chocolate and all the different types of chocolate into one health recommendation is wrong. And I know we'll dive into that a little bit. If we talk generally, chocolate does contain these very special bioactives, as we call them, called polyphenols. They contain some other chemicals, which Spencer said as well, called theobromine, and some chocolate.

Please note the emphasis on some is also high in fibre, but not all chocolate. There is some good evidence from what we call the epidemiological studies that I know Jonathan we often talk about, so these are studies where we look at whole populations and we look at patterns of food intake alongside patterns of disease that as people increase their chocolate intake, they reduce their levels of blood pressure, they reduce their incidence of type 2 diabetes,

they reduce their incidence of cardiovascular disease and so much more. The problem is, with that, is that most of those studies group all chocolate together. The other problem is, is there's lots of confounders. Do people that consume more chocolate also have different other health habits? So how we then translate that back

to what's on our supermarket shelf, is where it gets really tricky. And Sarah, do we have any idea what's going on? Like, why might eating chocolate be beneficial in the way in which eating all the other candy on the candy aisle? Like, I've never heard anyone argue that that's good for anybody other than maybe, you know, the income of my dentist. So I think there's a number of different reasons.

One could be the fibre, but again, the fibre content in chocolate is hugely variable. So in certain types of dark chocolate, and I think you might know better, Spencer, about the different levels of fibre and different chocolate. So we do know that chocolate that's processed in a particular way and very dark chocolate is quite high in fibre, is that correct? Yeah, so fibre is, and also the way in which the chocolate is crafted will make a huge difference to fibre. But most good dark chocolates will have four to seven grams of fibre inside them. And then if you use cocoa pulp sugar, which is going to get very esoteric in a sec, that is also. very, very high in fibre. So the actual the pulp which surrounds

the cocoa beans, cocoa seeds and the husk is also very, very high in fibre. So lots of chocolate makers are now trying to work out how to use that too. And then the other point is what you were talking about is theobromine. We've known since the 1920s is a good vasodilitis. It used to actually be given to asthmatics. So there is

some good evidence that as you said, using chocolate moderately is very, very good for you. Obviously, as nutrition scientists, we try and look at the whole food because the matrix, you know, I always talk about as important, but we look at the different components. So fibres is one of the components, particularly in dark chocolate. Do bear in mind, though, I'm not saying that we should be using that as our main source of fibre. In milk chocolate, it's actually very low. So from a bar of chocolate, you'll probably only get one or two

grams, if that. You might get three or four from a dark chocolate, but at a level at which I would say is quite healthy to consume, so not a large amount. You're not going to get a huge amount. But it still makes a contribution given that we're deficient of fibre, given that on average we only consume 20 grams and we should be increasing our fibre. So that's one mechanism and we know that increasing our fibre by three, five grams has huge impacts on our health. Another mechanism could be the fat in it, cocoa butter. And I think this is where it gets really interesting. And I actually studied cocoa butter as part of my PhD. I did some research on this because cocoa butter is very special. The reason it's special is it actually has about 60% saturated fat. And it's actually got

the same fatty acid composition. So the types of different saturated fats as beef fat. So I don't know if you've heard of beef tallow. We don't really use it much these days, but years ago, it was used. If I was to ask you, what do you think the health benefits of beef tallow are? Well, I think you've convinced me that the health benefits of beef tallow are really low. So beef teller has the same fatty acid composition nearly as cocoa butter. Yet if you feed cocoa butter to humans, we do not increase our cholesterol levels. It seems to have this cholesterol neutral effect compared to other fats that have a similar saturated fatty acid composition. And this is because it has a very unique structure.

Now, given that I did spend many years studying it, I am not going to spend the next hour, although I'd love to. Maybe I can do another one on cocoa butter. But it has a very special structure. and this special structure is actually one of the reasons why I think many people love chocolate as well as the taste because it has this wonderful mouth fill. So cocoa butter melts at body temperature and it's one of the few fats that actually melts in a single peak.

So you put it in your mouth and slowly it warms up to your body temperature and you have this beautiful mouth feel of it melting. And Spencer, you've mentioned the word craft chocolate a few times now. It's a word I had not heard five years. ago and which I think many of our listeners will not be familiar with. What do you mean by craft chocolate and why have you used that word carefully? So I'm using it because it signifies

a slightly different approach. And so if you think about it, you have craft beer, you have specialty coffee. Almost every sort of food and bread has got a campaign. And chocolate has had the same. And what craft chocolate is all about is basically giving you as much flavor as you can possibly get out of the cocoa beans. And cocoa beans have got more flavor complexity than just about anything else on the planet. And they're also transparently traded and crafted. So they're all about basically trying to give you flavor,

but also trying to work with the farmers so that the farmers will look after the rainforests and also have enough money to live on and not be sort of using child labor, et cetera. So it's a sort of win-win situation. And as a movement, it's probably been around for even longer than specialty coffee. but for various reasons we can go into it hasn't grown in the same way that say artisan cheese has

or craft gin has or craft beer or anything else but it's all about basically flavor and transparency and i think you know this is a really good time to think about again what we've said numerous times about the difference between the different types of chocolate because what we know is that what you see necessarily on the back of pack labelling i'm sure we're going to dive into this doesn't necessarily equate to the health outcomes so a chocolate could say it's 75 percent, 85% cocoa or chocolate solid. But actually, depending on how it's processed, where it's sourced from, et cetera, determines the different levels of the really active kind of potent polyphenols, because different polyphenols have different potencies and the particular ones

that are in chocolate. Some of them are converted to slightly different forms and the microbiome might play a role in this, except, and, you know, very, you know, and other factors. And so actually, the amount of cocoa solids is a crude measure, but it doesn't tell us exactly. And I think this is where it gets really interesting that what we realize is also from recent research is how important a microbiome is in actually reaping some of the benefits of this chocolate as well. And so there's been some really fascinating studies that have looked at how variable people's health responses are to the same chocolate. And we know that there's huge variability between maybe how I respond to it

to how Spencer will respond to it to how you might respond to it, Jonathan. And we believe that one of the reasons for this huge variability might actually be the microbiome. And the reason for that is that we know that the microbiome is involved in some of the kind of, using simple terms, activation of these amazing bioactives, these polyphenols.

And so what we know is that when you consume chocolate, you have this very rapid, improvement in blood vessel function after about two hours. So, Sarah, I just want to check. You're saying, actually, if you're eating the right chocolate, I could actually see an impact on my blood vessel in just two hours? Yes, so randomised control trials where they measure how much your blood vessels dilate,

see an improvement if it's the right type, right amount of flavonols after two hours. That's crazy. But what's really interesting is studies that have them measured it for a longer period of time. These are studies that have only come out in the last year or so, see a second kind of peak benefit around six to eight hours after. So about eight hours after you've eaten that. Now, you've not got these magic chemicals circulating in your blood from when you've just eaten it.

What we know is it's then reached your large intestine and what we know is that there are particular bacteria in your gut, so our microbiome, that play a role in activating some of these polyphenols and that then we have this second kind of benefit, at this second dilation. And obviously, everyone's microbiome differs, and this is why we see, we believe, this huge variability in your responsiveness to Coco. So not only is chocolate hugely variable, we are in how we process it and benefit from it.

In terms of some brands you can look for, I would strongly recommend you look at TASA, which has got a fantastically interesting texture. Can you spell that? T-A-Z-A or T-A-Z-A. And would you get that in a grocery store or High Street retailer? You will in America. In the UK? In the UK, almost impossible. So the UK is particularly difficult because it is very difficult to persuade any grocery store to sell any bar above, you know, £2, 3 pounds. We basically got into this habit that the way in which you sell chocolate, it's an impulse buy, it's generally sold over a vending machine, it is sold off price. And you cannot do that with good flavour some chocolate. So no, occasionally you'll see willies in some supermarkets in the UK, some grocery stores. But fundamentally, the

the UK has a really big challenge. If you go to Europe, a little bit different. In Europe, there are some good examples where you can get some of these craft chocolates. But it is a real challenge. It's not like specialty coffee. It's not like craft beer. We haven't broken through. We haven't explained to people how this is the most amazing tool to get you to think about flavor and health yet. But we will get that. I'll end this recap with something I think you'll like, a free gut health guide created by our team of scientists here at Zoe. Many of us aren't sure how to best support our gut. So we developed an easy-to-follow guide, complete with tips, recipes and shopping lists,

designed to help you look after your gut. The guide is delivered straight to your inbox, along with ongoing nutrition insights from Zoe, the Science and Nutrition Company on a mission to transform the health of millions. To get your free gut health guide, just visit zoe.com slash gut guide. Thanks for listening. You know,