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