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Hello and welcome to Zoe Shorts, the Bite Size podcast where we discuss one topic around science and nutrition. I'm Jonathan Wolf and as always I'm joined by Dr. Sarah Berry. Today's subject is artificial sweetness. So Jonathan, artificial sweeteners are everywhere, not just in diet soft drinks as many of us think, but they're throughout all kinds of processed foods and actually maybe in some places that you wouldn't even expect.
As they become more widespread, peach will naturally have lots of questions about how they compare to natural sugars. And there have been years of conflicting studies, so I think there's a lot to clear up about these sugar alternatives. Yeah, absolutely. And I think we can shed some light on the most important benefits and also the potential risks of these sweeteners. Brilliant. Well, let's go. We did some research and it turns out the first synthetic sweetener to really make an impact globally was saccharin.
It was discovered by accident in 1879 when a Russian chemist was studying coal and tar. Now the story goes that he was working with these chemicals, got a little on his hand and decided to give it a taste. And Eureka, we have our first sugar alternative, which sounds like a very risky way for a chemist to behave. I'm a little skeptical that this is really the story, but there you go. And within a few years, it had hit the market and was widely used during World War I because sugar was in short supply.
Great. I didn't know that, Jonathan. Really interesting. So it didn't actually stop after World War I, the development of sweeteners. There were more that were invented or discovered and they've become a really regular part of our diet as manufacturers have started to include them for some time now in more of the food and drink we regularly consume, mainly in an effort to reduce the energy and also the sugar content of food.
So when we speak about alternatives, a lot of people instantly think of diet soft drinks, which are where these sweeteners are most commonly seen by consumers. But it's really important to note that a whole wide range of foods use sweeteners that most of us probably aren't even aware of.
I'm now increasingly amazed by how many foods, when I look at the detail of the food wrapper, turn out to have sweeteners in it. But if you want to understand how sweeteners work, basically they fool our sweet taste receptors into thinking that we're actually eating sugar. And some of them can provide the same intense sweetness that we get with sugar. And they can deliver all of that taste in far lower portion sizes than you would do with sugar. Yeah. And something to be aware of, Jonathan, is that the term artificial sweetener is
probably a little misleading when we talk about sweetness because not all of them are artificial. Some sweeteners occur naturally, such as stevia. Some contain some calories, so are nutritive, and some are non-nutritive and have no calories.
But really importantly, sweeteners differ from one to another depending on how they're processed by the body, so how they're metabolised. And so it's really important not to group all sweeteners into one category. And this is unfortunately often done when considering their health effects in research. So basically you're saying, as always, it's complicated, Sarah.
As always, Jonathan, yes. And am I right that some of these naturally occurring sweeteners have actually been used for a long time? Yeah, so sweeteners like stevia, which is, as you say, naturally occurring and actually native to Brazil and Paraguay, and it's believed that they've been used for around 200 years. And stevia especially has seen a massive increase, though, in the last decade since it's been made legal in the EU in 2011 and in the US in 2008.
And Jonathan, I think something that's really important to say is that there's a whole host of different sweeteners, but the four most commonly consumed sweeteners in terms of the artificial sweeteners are called aspartame, ace K, saccharin and sucralise. And the type of sweeteners used vary from country to country and also vary depending on the products. And
What I think has really surprised me when I was researching this is that Diet Coke, for example, you drink in the USA, actually has a different kind of sweetener than the one that you buy in England. Yeah, I remember when we were looking at things between the US and the UK and just all this added complexity of like, even when they say the food's the same, you know, it can have different sweeteners. And people said these sweeteners are completely inert, but it doesn't matter. But if you start to realize, as we're discussing, that maybe they have some impact, then, you know, these two products might not be the same.
So we have these food and drink where the sweeteners in them are obvious because the food is actually marketed as low calorie or no sugar products. And then we have these sweeteners that are hidden in everyday things that we eat that are sort of processed.
Why do we consider using artificial sweeteners at all instead of just using sugar? So sugar is something we know has unfavourable long-term effects when we consume it in excess, which unfortunately the majority of people in the Western population do. And these include everything from obesity, diabetes and many other chronic ill effects.
So I guess the idea is if you can find an alternative to sugar that would reduce your overall sugar intake, then that should be beneficial. Yeah, absolutely. And there's two really key arguments for using artificial sweeteners. The first is that sugar substitutes have significantly less or no calories compared with real sugar. So it stands to reason that for people wishing to reduce their calorie intake, so their energy intake, swapping full sugar drinks for artificially sweetened drinks would be a good move for those individuals to reduce energy intake.
The other argument is that replacing sugars with artificial sweeteners will prevent the large peaks and dips in blood glucose that's typically seen after we eat sugar or any refined carbohydrates. And we know, Jonathan, from our own ZOE predict research, that these large peaks and dips in glucose are associated with really unfavourable health effects such as increased inflammation, elevated hunger after we've eaten and increased energy intake in the subsequent few hours.
So anything that can improve the blood sugar control and these peaks and dips in general is going to have a positive impact on our health. And I imagine on top of all of this, they're better for your teeth too? Yeah. So as a mum to two young kids who are partial to too much sugar, I'm happy to say that there's good research actually showing that specific artificial sweetener, particularly xylitol, can actually have a positive effect in relation to oral health.
So what about the other side? There was a time when you couldn't open up a newspaper without seeing headlines about the cancer risks linked to artificial sweeteners. Was there ever any science to back up these claims? I think let's take a step back and think of the four main arguments that I typically think are used against the use of sweeteners. And we can dive into each of these very briefly. So one is that, as you've said, they may increase the risk of cancer. Two is that they impair the effect of
glucose control. Three is that they may modify our microbiome composition so this is the ecosystem of trillions of bugs in our gut that we know are really important for our health and four is that they increase the desire in people for sweetness which ultimately over time might encourage the intake of other sweet foods containing sugar.
So maybe let's take that step by step. So starting with the risk of cancer that I remember reading about when I was younger. So again, we took a look at this. Cancer Research UK and the US National Cancer Institute are on record saying that there is no increased cancer risk regarding artificial sweeteners.
Overall, the evidence that linked cancer and sweeteners turned out to be thinner than initially feared. But I think a lot of those concerns are still attached to the product. People still have some of these fears, despite evidence that today there's really not the data to link about that. What about the effect on blood glucose control and on the microbiome?
On paper, you would think a sugar alternative that means you don't have these blood sugar peaks and dips, you know, should be really good, particularly with people, for example, with diabetes or prediabetes. Yeah, absolutely. And there's been a lot of research in mice showing that sweeteners, though, impair actually glucose control. Which is shocking, right? So the reverse of what you would expect.
Yeah. The problem is there hasn't been as much research in humans. But really interestingly, a paper that actually just came out this week from the Wiseman Institute showed that two particular sweeteners, sucralose and saccharin, impaired blood glucose control, while aspartame and a control had no effect.
That's fascinating. So they've really able to measure some real effect on human beings. And as you said, it's complicated because not all the sweeteners were the same. So one thing we haven't mentioned yet is the effect of sweeteners on weight. And I think we do have to touch on that because the whole idea of a diet soft drink is that you aren't drinking all of those calories. If you believe in calorie counting, then people should have lost weight, right? As they swapped out their full sugar Coca-Cola for Diet Cokes. So...
You know, Sarah, did it work? So, Jonathan, yet again, I have to say that we just don't know, unfortunately. There have been loads of clinical trials on this, actually. Overall, the evidence, in my opinion, suggests that changing from full sugar drinks or foods to low calorie alternatives with artificial sweeteners
will have either no effect or only a small effect on energy intake and body weight. So whilst having an artificially sweetened drink between meals might reduce your energy intake within that few hours, you know, at that specific point in time, studies tend to show that over a 24-hour period, we tend to maintain the same amount of energy intake irrespective of whether we swap our full sugar drink with an artificially sweetened drink. ♪
So Sarah, after all of this, in your opinion, sugar or sweetness? I think this is a really tough one, Jonathan, because I think without a doubt, we know that we're consuming too much sugar. In the US, adults consume an average of 77 grams of sugar a day. In the UK, it's around 56 grams. Which is a huge amount of sugar, right? If you imagine it just sitting in a bowl in front of you, right?
Absolutely. It's way above what the recommended amount is. So we need to reduce our sugar intake, full stop. It has to be reduced. What are we going to replace it with? Well, ideally, we would swap our full sugar Coke with water or maybe even some kind of milk.
But the reality is, is people want to make swaps that have the same functionality, whether it's the same consistency or the same taste. So an alternative, therefore, is going to be that artificially sweetened drink. I think in that instance, it's better than the full sugar drink. And I think I would probably be slightly stronger, Sarah, which is never going to surprise you, which is that
I think about this a little bit as a big scientific experiment over the last 40 years, which basically has failed. If you think about the starting point of this, I think there was great reason to believe that you could swap out all of this sugar with this sweetener, you were gonna collapse the number of calories that people would drink and therefore it would have this transformational effect
on obesity, which there was already concern. And in fact, the period when you really saw the rise of these diet drinks, we actually saw obesity going up even faster than before. So I think that this really failed. We don't really understand what impact this is having on our microbiome, and it makes it hard to manage that if you think these are foods that
don't have that. And where I think in many cases, you might have been much better to have a much simpler product that has some sugar in it than something that has swapped out to sweeteners. So am I far too radical here? No, I think there's a really important point to pick up on there that so many sweeteners are hidden. And the Wiseman study that I referred to earlier specifically recruited people that said that they do not consume artificial sweeteners. They then monitored their diet to see what foods they're consuming and
and they actually had to exclude the majority of the people. So recruitment was really hard for the study because people who thought they weren't consuming artificial sweeteners actually were in all of these products where they're hidden. - That is amazing, isn't it? We're living in this environment where we're trained for these incredibly sweet tastes. We're pushed towards these foods that tend to not fill you up for very long, partly because we've moved to a lot of sort of high carb, low fat foods.
And so, yeah, I agree with you. Drinking these full sugar drinks is shocking. If you see what happens to your blood sugar, we know that those peaks cause hunger later. And what's interesting therefore is why aren't these sweetened drinks more successful? So if they aren't really leading to much lower weight gain,
there's got to be some balancing things that aren't good. So my view would be, you know, try and avoid where possible. Okay, so my view is watch this space for more evidence. If I was given the choice, I would say to opt for water or milk. My second best option would be an artificially sweetened drink.
And I would choose that above a full sugar drink. And I think you've totally convinced me, Sarah. And I think we should definitely follow up on this topic soon because it feels like this is one of the areas where the science is really swiftly changing. And we're saying something quite different than we would have said even a couple of years ago. And sounds like that's continuing. Yeah. And I think calling something unhealthy or unhealthy, we need to be a little bit careful. I think what we can say is whilst...
There is no evidence to show that artificial sweeteners are healthy for us. On balance, I believe the evidence would show that they are a healthier alternative to a full sugar drink. I think that's a brilliant conclusion to come to. Sarah, as always, thank you for taking us through this complexity and this minefield. We will return to this topic again soon.
If based upon this conversation, you're interested to understand more about your own body, do think about trying Zoe's personalized nutrition program to improve your health and manage your weight. You can get 10% off by going to joinzoe.com slash podcast. I'm Jonathan Wolf. And I'm Sarah Berry. Join us next week for another Zoe podcast.