Niki Bezzant: The danger of artificial sweeteners

"Fake sugar" increases your risk of heart disease, high blood pressure and diabetes. Photo / Getty Images

Sugar is something we have all become a lot more aware of in recent years. The trend towards lower-sugar diets and products has only grown since everyone went on those sugar-quitting diets a few years back. It's commonplace now to see "reduced sugar"; "x% less sugar"; "no added sugar"; "no refined sugar", etc on labels now.

That's because manufacturers have jumped on to this consumer trend. Many have worked hard to change their products, remove sugar, and develop new lower-sugar ones.

This, in general, is a good thing; the less added sugar we have in our diets, the better. The World Health Organisation recommends we have no more than six teaspoons of added (or "free") sugar a day; not much when you consider there can be double that in a single bottle of fizzy drink.

But there's still a lot of confusion out there about what constitutes free sugar, where it hides and whether the things used to substitute for it are healthy for us. Some food producers, it seems to me, are playing fast and loose with their marketing claims, and the lack of rules around what can and can't be said about sweeteners, including sugar.

Of course, when a manufacturer – or indeed a cook in a home kitchen – wants to have less sugar in a food but want to keep the sweetness, we have to replace that sugar with something else.

The something else, for manufacturers, used to be straightforward artificial (technically known as non-nutritive) sweeteners. These are things like aspartame, saccharine and sucralose. These seem to have become a bit unfashionable in recent times, probably because they are perceived, rightly or wrongly, as being artificial and therefore bad or harmful.

That's interesting, since aspartame and its ilk are some of the most-studied food additives around; and the body of evidence suggests they are perfectly safe. And many nutritionists would say that if you have an artificially-sweetened drink instead of a sugar-sweetened one, that's a step in a healthy direction, because these sweeteners contain no kilojoules or calories. (It's better still to transition away from any sweet-tasting drink at all; but if you're a habitual sugary drinks consumer, going cold turkey might be a step too far).

There has been emerging research, though, which suggests a link between artificial sweeteners and an increased risk of heart disease, high blood pressure and diabetes. And there have been animal studies suggesting these sweeteners may have a negative effect on the bacteria in our gut.

So you may prefer to choose a product sweetened with something more natural. Stevia is practically ubiquitous as a sweetener these days; it's a good one for helping manufacturers to lower the sugar in a food but keep the sweetness, since stevia is intensely sweet but has practically no kilojoules. Stevia tends to have a bit of a bitter aftertaste, though, which some people dislike. Monk fruit extract is another one that's popping up a bit.

A newer trend in non-nutritive sweeteners is the use of things called sugar alcohols. These are things like sorbitol, mannitol and others that end in -ol. They're not kilojoule-free, but they have far fewer kilojoules than sugar. But there's a drawback with these.

They're part of a family called polyols, which if you have any issues with irritable bowel, you may recognise. Unfortunately for anyone with a grumbly gut, these are creeping into lots of foods, now, including yoghurts and cereals, and they can have quite a drastic effect if eaten in excess, even for people who don't have IBS. I've heard reports of people having terrible diarrhoea after eating a tub of what they thought was healthier, low-sugar icecream, for example.

Finally we have so-called "natural" sugars: things like honey, maple syrup, rice malt syrup, fruit juice and coconut sugar. Using these means a food marketer can say things like "no refined sugar" or "naturally sweetened" on a product.

This is misleading. All of the above sweeteners are classified as free sugars by the WHO, meaning they're no different from the white stuff. Using these can be a bit of a tricky way of being able to claim "no refined sugar" – but ultimately it's meaningless. Be very wary of anything bearing this kind of claim, whether it's a recipe or a breakfast cereal.

So what's the best thing to do when choosing sweet foods?

It's probably, as in most areas, to start with the whole and natural: fruit. The sugar in whole fruit is intrinsic: it's bound in with the healthy fibre and vitamins that are great for us. This kind of sugar is completely different from added sugar.

And when we're looking at other sweet foods, we want to get to a place where they really are an occasional treat, no matter what they're sweetened with.

Niki Bezzant is a food and nutrition writer and speaker, and editor-at-large for Healthy Food Guide www.healthyfood.com. Follow Niki @nikibezzant