Sweetening additives (aka artificial sweeteners) have a sweetness many times that of sugar with few to no kilojoules. This means they can be used in much smaller amounts than sugar – so they provide the sweetness without the extra kilojoules. Their advantages are that they don’t contribute to weight gain and they don’t feed the bacteria living on our teeth. But they are controversial.

How much is too much?

With many foods, it’s not what you eat that counts – it’s how much. 10 sweetening additives (also known as “intense sweeteners” or “non-nutritive sweeteners”) are approved for use here (see "Sweeteners compared", below) and they’re all regarded as safe.

Food regulators have set an Acceptable Daily Intake for most sweetening additives.
Food regulators have set an Acceptable Daily Intake for most sweetening additives.

However, to make sure you don’t consume too much of these sweeteners in your overall diet, the Australia New Zealand Food Standards Code stops them from being added to some foods. The Code also says they can only be added in specified amounts.

Food regulators have set an Acceptable Daily Intake (ADI) for most sweetening additives. This is the amount you could safely eat, per kilogram of your body weight, every day of your life. A 2003 survey commissioned by Food Standards Australia New Zealand (FSANZ) found we were most likely to get our sugar-free fix from diet drinks and confectionery, including chocolate and chewing gum.

The survey found that most people weren’t eating enough sweetening additives to pose any risk to their health. The only cause for concern was cyclamate. Although average intakes of this were below the ADI, some people aged 12 to 39 exceeded it – mainly from cordials, fruit drinks, soft drinks and table-top sweeteners. As a result the maximum levels permitted in water-based flavoured drinks were lowered.

It isn’t necessarily a health risk to eat more than the ADI over a short period of time. ADIs have substantial safety margins and are based on lifetime exposure to the additive.

Dietitians NZ supports the use of sweetening additives and their safety. Their official statement says that: “Sweeteners offer a safe low-energy option for anyone who wants or needs to limit their sugar intake. They are also an important step in weight management and diabetes control for many people.”

If you want to know if a sweetener’s in your food, look in the ingredients list. It’s listed under “sweetener” with its name or food-additive code number – for example, aspartame or 951. The website www.foodsmart.govt.nz has a downloadable booklet giving the code numbers. Sometimes both the name and the code number will be listed.

Aspartame

Aspartame is one of the most-studied food additives in the world and has been safely used for at least 25 years. It’s been reviewed by Food Standards Australia New Zealand (FSANZ), the FAO/WHO Joint Expert Committee on Food Additives, the European Food Safety Authority (EFSA), and the US Food and Drug Administration. Scientific evidence so far supports the safety of aspartame.

Despite this, aspartame is still controversial. There are claims it’s been associated with multiple sclerosis, vision problems, Alzheimer’s, and tumours. In 2007 the European Ramazzini Foundation (ERF) published a study that suggested aspartame could cause cancer in rats at levels close to the human Acceptable Daily Intake (ADI). The EFSA reviewed this study and concluded that on the basis of all the evidence, including the Ramazzini study, aspartame did not cause cancer and there was no reason to revise the ADI for aspartame. FSANZ agreed with its European counterpart’s conclusions.

In 2010, 2 further studies were published questioning aspartame’s safety. EFSA evaluated these studies and said there was no cause to reconsider previous safety assessments.

In December 2013 EFSA completed a full risk assessment on aspartame and concluded it’s safe at current levels of exposure.

Many people are adamant that aspartame adversely affects them. So the UK Food Standards Agency has launched a pilot study that’s testing individual sensitivity to aspartame through a double-blind placebo-controlled study. This may be useful in providing direction for future research and could provide insights into the issue of possible aspartame sensitivity.

Aspartame does carry a risk for a small number of people with the rare inherited disorder phenylketonuria (PKU). People with PKU should avoid aspartame because they are unable to break down phenylalanine, a component of aspartame. For this reason, all products containing aspartame must carry a warning label. (Babies are screened for PKU at birth.)

Other sweeteners

Advantame
The newest sweetening additive allowed is Advantame, approved in 2011. Advantame is derived from aspartame and vanillin. FSANZ independently evaluated toxicity studies on Advantame and concluded that its approval as a sweetener doesn’t raise any public health and safety issues.

Acesulphame-K
Acesulphame-K is not metabolised or stored in the body. After it’s consumed, it’s quickly absorbed by the body and then rapidly excreted unchanged.

It’s been claimed that acesulphame-K 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.

Alitame, neotame and thaumatin
There’s no evidence of any harmful effects from this group of sweeteners. Thaumatin has no Acceptable Daily Intake (that’s because it’s considered to have a very good safety profile).

Cyclamate
Animal studies in the 1960s suggested cyclamate was carcinogenic. This is no longer considered the case and it’s approved in many countries.

Saccharin
Saccharin has been linked with bladder cancer but there’s no definitive evidence it’s carcinogenic.

Stevia
Stevia (specifically steviol glycosides), was approved in 2008. Stevia is extracted from the Stevia rebaudiana plant and is considered a more natural sweetener than its artificial counterparts. It has been approved for use in many countries. But it has been controversial: the US Center for Science in the Public Interest says it’s been inadequately tested.

Sucralose
Sucralose is the only intense sweetener made from sugar. It’s chemically altered so can’t be digested. Numerous studies verify that it has no carcinogenic, neurologic or reproductive risk.

Sugar alcohols
Sugar alcohols such as erythritol and xylitol also act as sweeteners. They’re generally less sweet than sugar and are often used for their other properties (emulsifiers or thickeners). They can’t be fully digested, so eating too much can lead to diarrhoea. Erythritol and xylitol don’t have an Acceptable Daily Intake because they’re considered to have a very good safety profile.

“Better-for-you” sugar
Chelsea Sugar's LoGICane is raw sugar that has had molasses extract sprayed on it, resulting in a product with a lower GI than sucrose. Low-GI foods are useful for people with diabetes because they have a lower impact on blood-glucose levels. But LoGICane is still 100 percent cane sugar: weight-wise, it packs the same kilojoule punch as regular sugar.

Our view

  • There are clear benefits in consuming foods that contain a sweetening additive – especially if you need to limit your sugar or energy intake, or have diabetes.
  • Sweetening additives are usually in processed foods such as soft drinks and confectionery that don’t provide much nutritional content, so you shouldn’t be consuming them in large amounts anyway.

Report by Belinda Castles.