Information sheet: Intense sweeteners and cancer risk

Key messages

• The food supply in Australia is strictly regulated.
• The intense sweeteners used in the Australian food supply have not been found to increase the risk of cancer in humans in the quantities currently consumed by the population.
• While intense sweeteners are often used to assist with weight management, there is not strong evidence that this works.
• Foods and drinks that contain intense sweeteners are usually highly processed and therefore are not products that Cancer Council recommends consuming regularly.

Background

Intense sweeteners (sometimes called artificial sweeteners, non-nutritive sweeteners, sugar substitutes or low-calorie sweeteners) are used to replace added sugar in food and drink products. These products may be labelled as ‘diet,’ ‘low joule,’ ‘no sugar,’ ‘zero sugar’ or ‘sugar-free.’

Intense sweeteners are much sweeter than sugar and so are able to be used in small quantities. Some are created synthetically (often called “artificial sweeteners”) and some are extracted and concentrated from plant sources (e.g., Steviol glycoside from the stevia rebaudiana plant). The use of intense sweeteners in food and drink products reduces the sugar content and the energy content (kilojoules or calories) compared to the full sugar versions of these products.

The sweeteners approved for use in Australia are strictly regulated by Food Standards Australia and New Zealand (FSANZ).¹ FSANZ carries out safety assessments based on evaluations and acceptable daily intake levels set internationally, and taking into account current availability and consumption in Australia and New Zealand.

The peak organisation for research into the role of diet in cancer, the World Cancer Research Fund (WCRF), notes that there is no strong evidence that drinks made with intense sweeteners are a cause of cancer.² Cancer Council closely follows the WCRF and other major research and regulatory bodies internationally to keep our knowledge and advice up-to-date.

Current issues

In July 2023, the International Agency on Research into Cancer (IARC) and the Joint FAO/WHO Expert Committee on Food Additives (JECFA) released their updated findings on the intense sweetener aspartame. These two international agencies have different tasks; IARC is responsible for assessing the likelihood that a substance causes cancer, and JECFA is responsible for assessing the size of the risk. JECFA is also responsible for setting the Acceptable Daily Intake (ADI) – an amount that is deemed to be safe for people to consume.

Based on this research:

• IARC has classified aspartame as a Group 2B substance; possibly carcinogenic to humans. This is based on limited evidence that consumption of aspartame is associated with increased risk of hepatocellular cancer, the most common form of liver cancer.
• This classification is based on limited evidence of carcinogenicity in humans, limited evidence of carcinogenicity in animal studies and limited evidence of a mechanism by which aspartame could cause cancer.
• For breast cancer and haematological cancers (non-Hodgkin lymphoma and multiple myeloma), a consistent association with aspartame consumption could not be demonstrated.
• At the same time, JECFA has reviewed the evidence of public health risk associated with aspartame and found no convincing evidence to change the current Acceptable Daily Intake of aspartame (40mg/kg of body weight).
• Based on the most recent data, the vast majority of Australians are consuming well below the Acceptable Daily Intake for aspartame.
• To summarise; aspartame has been found to be a possible cause of liver cancer in humans, but only when consumed in high enough levels.

This change reflects new research and knowledge about the risks of aspartame for human health. It doesn’t change Cancer Council Australia’s recommendations:

• Cancer Council Australia recommends eating mostly whole foods that are minimally processed. Foods that are highly processed, including foods that contain any kind of intense sweetener, are not considered “everyday” foods. People who limit intake of highly processed foods will be limiting their intake of all intense sweeteners.
• Most Australian adults eat and drink a lot less aspartame than the ADI (the amount that is deemed safe). For a 70 kg person, the ADI is 2800 mg/day. The last time FSANZ assessed aspartame consumption in Australia and New Zealand (2003), the vast majority of people (95%) were having 628 mg or less per day, and half of people were having 124 mg or less per day.³
• To put this in context, for a can of soft drink containing 200 mg of aspartame, a person weighing 70 kg would need to consume more than 14 cans every day to exceed this limit, assuming no other aspartame was consumed from other sources.
• Although there is limited information on current intake levels, studies suggest that the use of aspartame in the Australian food supply is decreasing.⁴

Current consumption levels in Australia

FSANZ has not assessed the consumption levels of most intense sweeteners in Australia since 2003. At that time, the average exposure to each of the intense sweeteners under investigation was well below the Acceptable Daily Intake. Stevia consumption was assessed more recently using 2011/12 dietary intake data and found to also be well within the Acceptable Daily Intake.⁵ A survey of the Australian population intake in 2011/12 found 18% of adults and 9% of children had consumed intense sweeteners the previous day. Drinks, tabletop sweeteners, and yoghurts were the top sources of intense sweeteners in the Australian diet.⁶

There is limited information on current intake levels.⁷ Globally, use of intense sweeteners is increasing although information on their use and effect on dietary patterns is limited.⁷ A study into the Australian food supply found a slight increase in the proportion of food and beverage products containing intense sweeteners between 2015 and 2019, from 3.8% to 4.3%.⁴ In terms of specific intense sweeteners, the researchers found that the proportion of products containing steviol glycosides increased from 1.3% to 2.2%, while the proportion of products containing sucralose decreased from 1.6% to 1.3%, aspartame decreased from 0.8% to 0.6%, and acesulfame K decreased from 1.4% to 1.2%.⁴

Dietary recommendations

There is not strong evidence that the intense sweeteners permitted in the food supply cause cancer or are unsafe in the amounts typically eaten and drunk.

Intense sweeteners are often assumed to be useful for weight management. It seems logical that having less sugar and energy (kilojoules or calories) would result in weight loss (or at least less weight gain). Surprisingly, the evidence does not support this.^8-13 The World Health Organization has recently (2023) reviewed the evidence of the health effects of intense sweeteners, and found that replacing sugars with non-nutritive sweeteners results in reductions in body weight in the short-term, but in the longer-term, is associated with increased risk of obesity, type 2 diabetes, cardiovascular diseases, and mortality.¹⁴ Please note that the use of intense sweeteners for blood sugar control (for example in people with diabetes) was not considered in this review. For individualised information about the risks and benefits of intense sweeteners for you, talk to your health care professional.

As with all additives, the presence of intense sweeteners generally indicates that a food is more heavily processed. Intense sweeteners are usually present in foods which aren’t recommended as “everyday” foods; for example, soft drinks, snack foods and confectionary products. To reduce the risk of cancer (and to maintain good health more broadly), we recommend following the Australian Dietary Guidelines and choosing a wide variety of whole and minimally processed foods. Physical activity is also important to for achieving good health, avoiding excess weight gain and reducing cancer risk.

The most common way that people use intense sweeteners is in drinks. If you drink sugary drinks and think a “no sugar” or “diet” version might help you cut down on sugar, that may be a first step to reducing your intake of sugary drinks. However, no/low sugar soft drinks are still bad for your teeth, so aim to make water your preferred drink every day, and drink intensely sweetened drinks only occasionally and as a step towards cutting back on sugar-sweetened soft drinks broadly.

Policy context

Ongoing monitoring of the research into the role of intense sweeteners in both weight management and in cancer risk is recommended.

Cancer Council Australia supports continued monitoring of intense sweeteners in the Australian food supply. The National Nutrition and Physical Activity Survey 2011-12 is the most recent comprehensive source of data on what Australians eat and drink. Given the significant changes to the Australian food supply in the last 10+ years, Cancer Council also supports the recommendation of the National Preventive Health strategy that comprehensive national data on nutrition is enhanced and collected regularly. For example, an updated National Nutrition and Physical Activity Survey would provide up-to-date dietary intake data to inform food regulation and nutrition policy in Australia.