Sweeteners are typically used to reduce calories and curb sugar intake – but what are they doing to our overall wellbeing? We ask the experts for their verdict in this health guide.
What exactly is a sugar substitute?
A sugar substitute is any type of sweetener that replaces regular table sugar. Many varieties are available but most can be placed into three main groups: artificial sweeteners, sugar alcohols and natural or plant-based sweeteners.
Artificial sweeteners – These are synthetic or chemical based additives that are virtually calorie-free, and are very sweet compared to regular sugar so it can be used in smaller amounts.
For example, the artificial sweetener, aspartame, is 180 times sweeter than sugar (sucrose) and is commonly added to ‘diet’ or ‘zero’ soft drinks, some flavoured yoghurts, and is the main sweetening ingredient in Equal.
Other popular artificial sweeteners in Australian foods and drinks include saccharin, which is 300 times sweeter than sugar, and sucralose, which is 600 times sweeter than sugar and is the main ingredient in Splenda. Artificial sweeteners also go by the name intense sweeteners, and in Australia, they are regulated by the Food Standards Code (FSANZ).
Sugar alcohols – These are lower in calories than regular sugar but are not calorie free. They are also not as sweet as artificial sweeteners.
Popular examples of sugar alcohols are xylitol and sorbitol, which are naturally occurring in vegetables and fruits. They are typically marketed as naturally-derived sweeteners; however, they can be artificially produced as well. They are available in stores for tabletop use, and are usually found in sugar free chewing gums.
Plant-based and natural sweeteners – Stevia is the most widely known plant-based sweetener and is derived from the Stevia rebaudiana plant species, which is native to South America.
Stevia is calorie free and is roughly 300 times sweeter than regular sugar. Companies commonly market it as a natural sweetener, but it still falls under the FSANZ Code and is regulated alongside artificial sweeteners. Other natural sweeteners include common pantry items such as honey, molasses and syrup.
Are sweeteners good for you? A dietitian’s perspective
Artificial sweeteners and sugar substitutes are safe in discretionary foods and drinks, but people should think about the overall nutritional value of these foods in their diet, explains Joel Feren, Accredited Practising Dietitian and Spokesperson for the Dietitians Association of Australia.
“The key message here is you can still have sugar substitutes, they are safe, but at the end of the day we should be focusing on the whole foods,” he says. “It’s about the bigger picture.”
The real culprit, he argues, isn’t so much the occasional sugar in your cup of tea or coffee, rather the hidden sugars in everyday packaged sweet and savoury foods such as cooking sauces, breakfast cereals, flavoured yoghurts and frozen meals.
When it comes to soft drinks, if you have to have one, make it a diet or sugar free variety
Earlier this year, consumer advocacy group CHOICE found that some frozen meals and cooking sauces contained up to 30 grams of sugar per serve. That’s as much sugar in a regular can of soft drink.
When it comes to drinks, the gold standard is always water, Feren says. But if you must reach for a soft drink, a diet or sugar free variety is a better option for blood sugar and weight control.
Juices and smoothies can be naturally sweetened with fruit, but again, Feren argues that people should be consuming the whole fruit, as valuable nutrients including fibre are lost when you juice.
No increase in cancer risk
Much of the controversy surrounding artificial sweeteners and cancer relates to mice studies dating back to the 1970s. However, a 2007 review by the World Cancer Research Fund found that “the evidence … does not suggest that chemical sweeteners have a detectable effect on the risk of any cancer.”
Another review by the European Food Standards Agency (EFSA) in 2013 found that the artificial sweetener aspartame is not linked to adverse effects in healthy individuals.
The only adverse effect from aspartame, warns Feren, is in people with a genetic condition called phenylketonuria. People with this genetic condition, which is typically diagnosed at birth, are advised against consuming products with aspartame.
Gut health and stomach intolerances
Although deemed safe for consumption, some sweeteners can cause gut problems if consumed in large amounts. For example, sugar alcohols such as xylitol and sorbitol may have a laxative effect or result in bloating and diarrhoea.
There is also increasing research suggesting that some sweeteners can affect our gut microbiome – that's the community of good and bacteria living in our gastrointestinal tract.
However, not all sweeteners have the same effect. A 2016 review by University of California researchers found that artificial sweeteners such as aspartame and saccharin disrupt the gut microbiome; while natural sweeteners, isomalt, lactitol and maltitol, could have potential health benefits by increasing the diversity of good bacteria in the gut.
Importantly, everyone has a different microbiome and there are many factors, outside of diet, that determine our reaction to certain foods and drinks. So, what is considered a healthy gut microbiome for one person may not be necessarily healthy for another – which is why one person will experience bloating or stomach upset with one type of food and the next person will not.
The best advice for people who suspect they are experiencing side effects or intolerances from sweeteners is to chat to your doctor to determine the exact cause and rule out other health concerns.
What about the effect of sweeteners on our oral health?
In terms of dental health, sugar substitutes are better than table sugar, says Sydney-based dentist, Dr Josephine Ha.
“Plaque is like a sticky bio-film that is left by food and sugar, and within that plaque are bacteria, known as streptococcus mutans,” she explains. “These bacteria feed on sucrose and produce an acid that, if left on the teeth for a long time, causes dental decay.”
Some sugar substitutes are even shown to prevent decay from occurring, says Dr Ha.
“Obviously, one benefit of sugar substitutes is that people are consuming less sugar but some sweeteners also have an anti-decay effect. For example, streptococcus mutans cannot digest xylitol, therefore the bacteria starve and die.”
Dr Ha says that the sugar alcohol sorbitol has been shown to have a similar effect. Stevia has also shown to be anti-bacteria causing, by decreasing the number of bacteria in the plaque itself.
Consuming acidic drinks and sugary foods contribute to tooth decay
While Dr Ha advocates using a sugar substitute over table sugar, she cautions that there are many reasons to reduce overall sugar intake, including sweeteners.
“Just because you are taking a sugar substitute this doesn’t mean you shouldn’t be brushing your teeth,” she says. “Decay is very multifactoral.”
She adds that in some drinks, it’s not just about the sugar or sweetener, it’s the acid that contributes to dental decay.
For example, plain water has a pH of 7, which is neutral. However, lemon juice has a pH of 2, and diet soft drinks have a pH of 3, which is considered highly acidic for the teeth.
“If you take a short cut and drown your teeth in lemon drinks and diet carbonated drinks you could be doing more harm than good,” she says.
People who experience dry mouth, or anyone who experiences dry mouth as a side effect of taking many medications, are also at greater risk of dental decay from sugar and acidic foods.
“If they have sugar and acidic foods, and then miss a spot from brushing they will end up with dental decay 2-3 times faster than other people,” says Dr Ha.
As part of good dental hygiene, she recommends using flouride toothpaste and regular flossing as priority in most patients.
In high-risk patients, for example those with dry mouth and people with lots of dental work, she recommends supplementing with flouride mouthwash and sugar free chewing gum.
How are you cutting down your sugar intake? Let us know in the comments below.