Sugar-free gum is sweetened with sugar alcohols, intense sweeteners, or a blend of both. The sugar alcohols, called polyols, are things like sorbitol, xylitol and erythritol, and they do most of the work. The intense sweeteners, such as aspartame and sucralose, are hundreds of times sweeter than sugar and are added in tiny amounts to top up the taste. Which ones a gum uses changes how it tastes, how it behaves in your gut, and whether it is safe around your dog.
Why gum stopped using sugar
Ordinary sugar is food for the bacteria in dental plaque, which turn it into acid. That is the basic reason sugary snacks are bad for teeth, and it is a particular problem for something you hold in your mouth for twenty minutes. Sugar-free gum exists because manufacturers needed sweetness that plaque bacteria cannot easily use. The polyols were the answer, and they have been the backbone of the category since the 1970s.
The polyols
Polyols are sometimes called sugar alcohols, though they contain no alcohol in the drinking sense. They are carbohydrates with a structure that makes them taste sweet but resist fermentation by mouth bacteria. Four turn up in gum regularly.
Sorbitol is the most common sweetener in mass-market sugar-free gum, because it is cheap and stable. It is about 60 per cent as sweet as sugar, so it is nearly always blended with something stronger. It is also the polyol most likely to cause digestive upset if you have a lot of it.
Xylitol is roughly as sweet as sugar, gram for gram, which is why it can carry a gum on its own. It occurs naturally in small amounts in fruit and vegetables and is produced commercially from birch wood or corn cobs. It has a cooling effect on the tongue that suits mint flavours. Two things to know: it can have a laxative effect in large amounts like all polyols, and it is toxic to dogs, so packs need to stay out of a dog's reach.
Erythritol is about 70 per cent as sweet as sugar and stands out from the other polyols in one useful way. Most of it is absorbed in the small intestine and passed unchanged in urine, rather than reaching the large intestine where the others cause trouble. That makes it the gentlest of the group on the gut. It has almost no calories and a clean, slightly cool taste.
Maltitol and mannitol appear less often in gum. Maltitol is used more in chocolate and lollies; mannitol is often a dusting on the outside of a stick of gum to stop it sticking to the wrapper.
The intense sweeteners
These are not carbohydrates at all. They are compounds so sweet that a few milligrams do the work of a teaspoon of sugar, and they are used to sharpen the sweetness of a polyol base.
Aspartame is around 200 times sweeter than sugar. It is one of the most studied food additives in existence and is approved by food regulators in Australia and worldwide within set daily limits. Products containing it must carry a warning that they contain phenylalanine, because people with the rare genetic condition phenylketonuria cannot process it. Plenty of people prefer to avoid it anyway, and it is the sweetener most often looked for on a label by people who read them.
Acesulfame potassium, usually listed as acesulfame K, is also around 200 times sweeter than sugar and is often paired with aspartame because each masks the other's aftertaste.
Sucralose is around 600 times sweeter than sugar, made by modifying a sugar molecule, and is very heat stable, which matters more in baking than in gum.
What the label warnings mean
Two warnings show up on sugar-free gum in Australia, and both are required by law rather than added by choice.
"Excess consumption may have a laxative effect" is mandatory on products that contain polyols above a set level. It is there because polyols draw water into the gut and are fermented by bacteria in the large intestine. For most people, a few pieces of gum a day is nowhere near the amount that causes a problem. A whole pack in one sitting might be.
"Contains phenylalanine" is mandatory on anything sweetened with aspartame, for the reason above. If you do not have phenylketonuria, it does not apply to you.
What Perli uses
Perli is sweetened with xylitol and erythritol, and nothing else. Xylitol because it is sweet enough to carry the flavour without an intense sweetener on top, erythritol because it rounds out the taste and is the polyol that is easiest on the gut. There is no aspartame, no acesulfame K and no sucralose in it. The laxative warning is on the pack because the rules require it for any polyol product, and we would rather print the warning than swap the sweetener for something we would not want to name.
The full ingredient list is on every pack and on each product page. For the other half of the label, the part that is usually hidden behind the words "gum base", read what chewing gum is actually made of.
Quick answers
Is xylitol natural?
It occurs naturally in small amounts in many fruits and vegetables, and is produced commercially from birch wood or corn. The commercial product is refined rather than extracted whole, so it sits somewhere between natural and manufactured, like most food ingredients.
Is aspartame safe?
Food regulators in Australia and internationally consider it safe within the set daily intake, which is far above what anyone gets from gum. People with phenylketonuria must avoid it. Perli does not use it.
Why does sugar-free gum say it may have a laxative effect?
Because polyols draw water into the gut and are fermented in the large intestine if you have enough of them. The warning is required by law above a set polyol level. A few pieces a day is well below the amount that causes problems for most people.
Which sweetener is easiest on the stomach?
Erythritol. Most of it is absorbed before it reaches the large intestine, so it causes far less digestive upset than sorbitol or xylitol at the same amount.
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