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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 Barry 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 maybe in some places that you wouldn't even expect.

  • As they become more widespread, people 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.

  • 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.

  • And to start with, we did some research and it turns out the first synthetic sweetener

  • to 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 his 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 sceptical that this is 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, that's really interesting.

  • So you know, it didn't stop after world war I, the development of sweeteners, there were

  • more that were invented or discovered, and they've become a 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.

  • That's right.

  • And 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 them.

  • But if you'd wanna understand how sweeteners work, basically they fool our sweet taste

  • receptors into thinking that we're 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 sweeteners.

  • because not all of them are artificial.

  • Some sweetness occurs naturally such as Stevia.

  • Some contain some calories, so are nutritive and some are non-nutritive and have no calories.

  • Importantly, sweeteners differ from one to another, depending on how they're processed

  • by the body.

  • So how they're metabolized.

  • So it's really important not to group all sweetness 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 been used for a

  • long time?

  • Yeah.

  • So sweeteners like Stevia which is, as you say, naturally occurring and 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 in the last decade since it was made legal in the EU in 2011

  • and the US in 2008.

  • And Jonathan, I think something really important to say is that there is a whole host of different

  • sweeteners, but the four most commonly consumed sweeteners in terms of artificial sweeteners

  • are called as Aspartame, ACE K, Saccharine and Sucralose and the type of sweeteners used

  • vary from country to country and also vary depending on the products and what I think

  • really surprised me when I was researching this is that diet Coke.

  • For example, you drink in the USA has a different kind of sweetener than the one that you buy

  • in England.

  • 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' it doesn't matter.

  • But if you start to realize, as we're discussing, that maybe they have some impact, then these

  • two products might not be the same.

  • So we have these food and drinks where the sweeteners in them are obvious because the

  • food is 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 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 could find an alternative to sugar that would reduce

  • your overall sugar intake, then that should be beneficial.

  • Yeah and there are two key arguments for using artificial sweeteners.

  • The first is that sugar substitutes have significantly fewer 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 predicts 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 blood sugar control and these peaks and dips in general is gonna

  • 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 showing that specific artificial sweeteners, particularly xylitol, can 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 risk 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 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 links cancer and sweeteners turned out to be thinner than initially

  • feared.

  • 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 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.

  • There's been a lot of research in mice showing that sweeteners impair 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 interestingly,

  • a paper that 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 been able to measure some real effects on human beings.

  • And as you said, it's complicated because not all the sweetness

  • was

  • 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, did it work?

  • Um, so Jonathan, yet again, I have to say that we just don't know.

  • Unfortunately, there have been loads of clinical trials on this 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 at that specific point in time, studies tend to show that over

  • 24 hours, 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 sweeteners.

  • I think this is a really tough one, Jonathan because I think without a doubt, we know that

  • we are consuming too much sugar in the US adults consume an average of 77 grams of sugar

  • a day in the