Are artificial sweeteners better than sugar?

These intense sweeteners (also known as artificial or natural intense sweeteners) have a sweetness many times that of sugar, but with few to no kilojoules. This means you can have your cake without looking like you’ve eaten it too.

However, many of these additives have been dogged by controversy for decades, with claims they may cause you more harm than good. We look at the evidence and whether artificial sweeteners really are a better bet.

What’s the issue?

Most debate has focussed on whether intense sweeteners can cause cancer, with aspartame in particular hitting the spotlight.

Back in 2005, the European Ramazzini Foundation published a study suggesting aspartame could cause cancer in rats when consumed at levels close to the Acceptable Daily Intake (ADI) for humans.

The report got widespread attention and prompted a review by the European Food Safety Authority (EFSA). It concluded there was no reason to revise aspartame’s ADI. In 2013, EFSA completed a full risk assessment on aspartame and concluded it was safe to use at current levels of consumption.

According to the Cancer Society, there’s no reliable evidence linking intense sweeteners, including aspartame, with any kind of cancer. Many of the studies suggesting a link have been on rats, which were fed large quantities of sweeteners, and didn’t show the products were carcinogenic to humans.

Government agencies have also found them to be safe. The Ministry of Health states current evidence shows intense sweeteners are safe to use for most people and can play a role in a healthy diet.

Foods Standards Australia New Zealand (FSANZ) said all intense sweeteners undergo a safety assessment. If they’re approved, the Food Standards Code restricts the amount used and types of food to which they can be added. These restrictions are intended to make sure you don’t consume too much.

However, there are still some unanswered questions about these ingredients.

There’s new and emerging evidence that intense sweeteners may change the numbers and type of bacteria in our gut. The research on the role of gut bacteria suggests the sweeteners may affect digestion, immune function and regulation of metabolism. A 2019 review, published in Advanced Nutrition, concluded further research on the effects was needed.

Better health?

Switching to “diet” and “sugar-free” products may seem an effective way to cut back on sugar. But a 2019 systematic review, published in the British Medical Journal, concluded there was no compelling evidence to indicate health benefits of non-sugar sweeteners for a range of health outcomes.

The review, commissioned by the World Health Organization (WHO), looked at 56 studies and found evidence that sweeteners might have a small beneficial effect on body mass index and blood sugar levels.

However, other studies showed people who frequently consumed more of these sweeteners gained more weight than those who consumed less. For other outcomes, such as diabetes risk and heart disease, the studies showed no benefit or harm.

More research is needed. Of the limited studies identified for each outcome, the review found most were poor quality. It also concluded potential harms from consuming non-sugar sweeteners couldn’t be ruled out.

EFSA is re-evaluating the data on intense sweeteners. The evaluation excludes aspartame, which was reviewed in 2013.

Cutting back

Dietitians New Zealand spokesperson Helen Gibbs said intense sweeteners offer an option for people looking to limit their sugar intake.

However, they should be viewed as “transitional” products – a way to cut back on sugary foods, rather than a long-term alternative.

“Humans are hardwired to enjoy sugar and intense sweeteners [help] maintain a preference for sweet foods, rather than training our taste buds to enjoy a wider range of tastes,” Gibbs said.

She also said choosing a food or drink with an intense sweetener isn’t a green light to eat or drink that product in large quantities.

New Zealand Dental Association sugary drinks spokesperson Dr Rob Beaglehole said the main concern with artificially sweetened drinks, from a dental perspective, is their acidity.

“Despite being sugar-free, these drinks are highly acidic and can cause dental erosion, which dissolves the tooth enamel. Once the enamel is lost, it’s lost forever. These drinks also maintain a desire for sweetness,” Dr Beaglehole said.

He said there’s also new and emerging evidence that links artificially sweetened beverages with weight gain and type-2 diabetes.

Types of sweeteners

Twelve sweeteners are approved for use in New Zealand. If you want to know what’s in a product, check the ingredients list. Under “sweetener”, you’ll find the name or food-additive code number - for example, aspartame or 951. Sometimes both the name and number will be listed.

Intense sweeteners

Acesulphame-potassium (acesulphame-K): It’s been claimed acesulphame-potassium is associated with tumours of the lungs and glands in rats, and with increased cholesterol levels in diabetic rats. But more than 90 studies have verified its safety. The sweetener isn’t metabolised or stored in the body.

Advantame: Approved in 2011, advantame is derived from aspartame and vanillin. FSANZ assessed toxicity studies on advantame and concluded its use as a sweetener didn’t raise any health and safety issues.

Alitame: There’s no evidence of any harmful effects from alitame. It is rarely used in food products.

Aspartame: It’s one of the most-studied food additives in the world – aspartame has been reviewed by FSANZ, the Food and Agricultural Organization/WHO Joint Expert Committee on Food Additives, EFSA and the US Food and Drug Administration. Current evidence supports aspartame being safe.

Aspartame does carry a risk for people with the rare inherited disorder phenylketonuria (PKU), which is screened for at birth. People with PKU are unable to break down phenylalanine, a component of aspartame. For this reason, products containing aspartame must carry a warning label.

Aspartame breaks down at high temperatures, so can’t be used in baking or cooking.

Aspartame-acesulphame salt: A combination of aspartame and acesulphame-potassium. People with PKU should avoid this sweetener.

Cyclamate: Animal studies in the 1960s suggested cyclamate was carcinogenic and it was banned in the US in 1969. However, it’s approved in many countries. The International Agency for Research on Cancer (IARC) states there’s insufficient evidence that cyclamate causes cancer.

Neotame: It’s a modified form of aspartame but only releases small amounts of phenylalanine, so doesn’t need an advisory label for people with PKU. There’s no evidence of harmful effects from neotame.

Saccharin: In the 1970s, saccharin was linked with bladder cancer in animals and was listed as a possible carcinogen by IARC. Saccharin has since undergone review and been removed from the IARC list.

Sucralose: Sucralose is the only intense sweetener made from sugar. It’s chemically altered and can’t be broken down once consumed. Numerous studies verify it has no carcinogenic, neurologic or reproductive risk.

Natural intense sweeteners

Monk fruit extract (luo han guo): Derived from the Siraitia grosvenorii fruit, monk fruit extract is the new sweetener on the block. It’s often combined with stevia or sugar alcohols.

Steviol glycosides (Stevia): Stevia is extracted from the Stevia rebaudiana plant. There’s no evidence of any harmful effects from steviol glycosides.

Thaumatin: Derived from the katemfe fruit, there’s no evidence of any harmful effects from thaumatin.

Other sweeteners

Sugar alcohols: Sugar alcohols include erythritol, isomalt, lactitol, mannitol, sorbitol and xylitol. They’re generally less sweet than sugar and often perform other functions such as emulsifying or thickening. They can’t be fully digested, so eating too much may have a laxative effect. Advisory statements are required on products containing high levels.

“Natural” sugar alternatives: Sweeteners such as honey, brown rice syrup, maple syrup and coconut sugar are often touted as being better for your health than regular sugar. However, they contain the same number of kilojoules as sugar and their small amounts of additional nutrients have no extra health benefits.

Compare sweeteners

How much is too much?

Most sweeteners have an Acceptable Daily Intake (ADI), which is set by government health bodies. This is the daily amount you could safely eat, based on your body weight. ADIs have safety margins and are calculated on lifetime exposure to the additive. For example, to exceed the ADI for aspartame, a 75kg adult would need to drink a 5.6L diet soft drink daily over a lifetime.

There are no recent data about how much of these additives we’re consuming. A survey commissioned by New Zealand Food Safety and FSANZ is underway.

The World Health Organization (WHO) recommends free or added sugars should make up less than 10 percent of your daily energy intake. It advises sticking to less than five percent for additional health benefits.

Its guidelines apply to all sugars added to food and the sugars present in honey, syrups, fruit juices and fruit concentrates (but not sugars that naturally occur in milk and whole fruit).

For an adult, five percent is about 25g or six teaspoons. Children should eat less than this.

We consume much more than 25g. In 2017, a study published in Nutrients estimated half of Kiwi adults eat about 57g (14 teaspoons) each day.

Six ways to cut sugar

Here are six tips for cutting back on the sweet stuff.

1. Check the ingredients list: Common aliases for sugar include fructose, glucose, corn sugar, dextrose, honey, lactose, maltose and sucrose.
2. Reduce added sugar gradually: Over time, your taste buds will be trained to enjoy less sugar. Most recipes won’t be affected if you reduce the sugar content.
3. Watch what you drink: Soft drinks, juices and sports drinks are major contributors of sugar, and can quickly rack up extra kilojoules. Water should be your go-to most of the time.
4. Use spices: Adding cinnamon, ginger or nutmeg can add flavour and help you reduce the amount of sugar you use.
5. Choose healthier options: Sugary treats such as confectionery, sugary cereals and muesli bars should only be eaten occasionally.
6. Sensible serving sizes: Be aware of portion sizes. You will eat more sugary foods if servings are larger or you eat straight from the packet.