Information sheet: Intense sweeteners and cancer risk
Key messages and recommendations
The use of intense sweeteners in Australian food products is regulated by Food Standards Australia and New Zealand.
Intense sweeteners, sometimes called artificial sweeteners, sugar substitutes or low-calorie sweeteners are substances that are used instead of sugar to sweeten foods and beverages. Intense sweeteners are many times sweeter than sugar which means they can be used in much smaller amounts. They are added to food and drinks – often labelled as ‘diet’ foods or drinks – to provide lower kilojoule (calorie) or sugar-free alternatives and may assist with controlling energy intake.
Several intense sweeteners have been approved for use in Australia including alitame, acesulfame potassium (Ace K), aspartame, advantame, cyclamate, neotame, saccharin, sucralose, steviol glycosides and thaumatin. Intense sweeteners are regulated by Food Standards Australia and New Zealand (FSANZ) under the Food Standards Code. FSANZ carries out safety assessments based on evaluations and acceptable daily intake levels set by the Joint Food and Agriculture Organization and World Health Organization Expert Committee on Food Additives (JECFA).
The list below contains the most common sweeteners used in Australia (including their international code number) which will be the subject of this position statement.
- Aspartame 
- Cyclamate 
- Saccharin 
- Sucralose 
- Steviol glycosides*
*Derived from the Stevia plant
In Australia, intense sweeteners are assessed for safety following an internationally accepted model (Codex Alimentarius). Extensive testing of intense sweeteners is conducted in laboratory animals to assess safety. A substance is only approved if there are no harmful effects. Safe concentrations of intense sweeteners determined from animal studies are divided by a safety factor to provide a health based guidance value for humans. The acceptable daily intake (ADI) is the amount of an intense sweetener that can be eaten every day for an entire lifetime without adverse effect. This means that the amounts of intense sweeteners that are permitted in foods are usually significantly lower than the quantities used in safety testing.
Aspartame is composed of two amino acids, aspartic acid and phenylalanine, and provides 17 kilojoules per gram of energy. It is about 200 times sweeter than sugar so only very small amounts are required to give the same level of sweetness. It is used in low kilojoule or sugar-free foods, including carbonated soft drinks, table top sweeteners, flavoured yoghurt, confectionery and weight management products. Aspartame entered the market in 1981 and is sold under the brand names Nutrasweet® and Equal® in Australia.
Early animal studies showed that aspartame does not have any carcinogenic effects. Safety concerns around potential carcinogenicity of aspartame first were raised in 2006 when the European Ramazzini Foundation published studies linking various cancers in rats with aspartame consumption. The European Food and Safety Authority (EFSA) reviewed all unpublished data from the European Ramazzini Foundation studies as well as all other available studies, and concluded that there was no reason to revise the previously established ADI for aspartame of 40 milligrams per kilogram of body weight per day (mg/kg body weight). The World Cancer Research Fund (WCRF) also reviewed evidence in 2007 and concluded that the evidence did not suggest chemical sweeteners, including aspartame, had a detectable effect on the risk of any cancer.
A case-control study in the United States (US) on aspartame found no increased risk of brain cancer from aspartame consumption in children. A cohort study on adults in the US also found no association between brain cancer and aspartame-containing beverages. The current epidemiological evidence does not support a link between aspartame and brain cancer.
Key regulatory authorities around the world including JECFA, EFSA and the US Food and Drug Administration (USFDA) permit the use of aspartame. EFSA published their first full risk assessment of aspartame in December 2013 and concluded that aspartame was safe for the general population including infants and pregnant women at the current ADI of 40 mg/kg, with the exception of people with phenylketonuria (PKU). The ADI is not applicable to people with PKU which is a rare genetic disorder that affects the way the body breaks down phenylalanine. FSANZ has agreed with EFSA’s assessment and has set an ADI for aspartame of 40 mg/kg body weight in Australia. As a risk management approach, FSANZ initiated mandatory labelling to alert people with PKU that the product contains phenylalanine.
A survey conducted by FSANZ in 2003 examined the amount of aspartame eaten in Australia. It was found that average consumers of aspartame were consuming 6% of the ADI, and high consumers were having 15% of the ADI, well below the levels at which adverse health effects could occur.
Cyclamate has no kilojoules and is 30 times sweeter than sugar, making it the least potent artificial sweetener. It is used most commonly in cordials/fruit drinks, carbonated soft drinks, desserts, confectionery and as a table top sweetener. It is often used with other artificial sweeteners especially saccharin and is under the brand name Sucaryl® in Australia.
An animal study in 1970 found an increased incidence of bladder cancers in rats exposed to a mix of cyclamate and saccharin. This led to a ban on the use of cyclamate in a number of countries, including the US and the United Kingdom. However, this association between bladder cancer and cyclamate could not be reproduced in other animal studies.
The International Agency for Research on Cancer (IARC) reviewed all the available evidence on cyclamates in 1980, 1987 and 1999 and concluded that there was inadequate evidence that cyclamates cause cancer in humans or animals. Studies indicate that cyclamates are largely excreted in urine unchanged, apart from small amounts which are converted by gastrointestinal microflora to cyclohexylamine which is absorbed by the body.
There are very few epidemiological studies of cyclamate on its own in humans as it was approved for use after saccharin and most products contain a mixture of both sweeteners. One of the few studies of cyclamate on its own includes a population-based case-control study in Denmark where 11% of the subjects reported having consumed cyclamate only. This study reported that there was no indication that cyclamate use increased the risk of bladder cancer.
Further evaluation of the data available for cyclamate by both USFDA and JECFA concluded that cyclamate was not a carcinogen. JECFA has recommended an ADI for cyclamates of 11 mg/kg body weight. FSANZ conducted a safety assessment of cyclamates in 2007 and concluded that this ADI adequately protects consumers. Exposure assessments by FSANZ found that all people over 12 years and 95% of children aged 2-11 years consume cyclamates within this ADI in Australia. FSANZ has reduced the maximum amount of cyclamates allowed in flavoured drinks to ensure exposure to cyclamates in Australia is within safe limits.
Cyclamate remains banned in the US, however, the USFDA’s concerns about cyclamate are not cancer related.
Saccharin is about 200-700 times sweeter than sugar and has no kilojoules as it is not metabolised by the body. It is commonly used in cordials/fruit drinks, carbonated soft drinks, baked goods, desserts, confectionery as well as toothpaste and mouthwash. It is sold under the brand names Sugarless®, Sugarine® and Sweet’n Low® as a table top sweetener in Australia.
Saccharin is the oldest and the most widely researched intense sweetener available. Studies in rats in the 1970s and 1980s linked high saccharin consumption with an increased risk of bladder cancer. As a result of these studies, saccharin was banned in Canada in 1977. In 1980, IARC listed saccharin as a possible carcinogen in humans and it was subsequently banned in the US in 1981. It has since been found that the mechanism by which saccharin causes cancer in rats is not relevant to humans.
Epidemiological studies have found no consistent evidence that saccharin is associated with bladder cancer incidence in humans. A Canadian study showed a positive correlation between consumption of artificial sweeteners, particularly saccharin, and bladder cancer in men. At the same time, a large study in the US found no correlation between bladder cancer and consumption of artificial sweeteners.
In 1999, IARC concluded that saccharin produces bladder cancer in rats by a non-DNA-reactive mechanism that is not relevant to humans because of critical differences between rats and humans. IARC removed saccharin from being a possible carcinogen as there was inadequate evidence in humans .
Due to lack of clear evidence that saccharin causes cancer in humans, in 2000 the US National Toxicology Program removed saccharin from the list of substances reasonably anticipated to be a human carcinogen in their Ninth Report on Carcinogens. The US and Canada have lifted their ban on saccharin.
FSANZ has conducted a safety assessment on saccharin and has set an ADI for saccharin of 5 mg/kg body weight based on recommendations by JECFA.
Sucralose is about 600 times sweeter than sugar and has no kilojoules as it is not metabolised by the body. It is commonly used in carbonated soft drinks, flavoured yoghurts, cordials/fruit drinks and sports products. Sucralose is sold under the brand name Splenda® as a table top sweetener in Australia.
Epidemiological evidence and regulation
Extensive testing has established the safety of sucralose and it has been shown to be non-carcinogenic. The European Commission’s Scientific Committee on Food found adequate evidence that there were no concerns around carcinogenicity for sucralose. The ADI set for sucralose by JECFA, and accepted by FSANZ, is 15 mg/kg body weight.
Steviol glycoside is a natural sweetener derived from the Stevia Rebaudiana plant. It is 200-300 times sweeter than sugar and contains no energy. It is a relatively new sweetener in Australia but has been used in Japan for more than 30 years. It is sold under the name Stevia in Australia.
Epidemiological evidence and regulation
FSANZ conducted a comprehensive risk assessment prior to approval of steviol glycoside in 2008, and concluded that it is unlikely to have adverse effects on health at doses up to 11 mg/kg body weight. Extensive research has been done on steviol glycosides involving both humans and animals. After analysing all the available evidence, EFSA's reviewing panel concluded that steviol glycosides are not carcinogenic, toxic or pose a risk to pregnant women or children.
Current consumption levels in Australia
FSANZ has assessed the consumption levels of intense sweeteners in Australia by conducting two surveys in 1994 and 2003. The surveys aimed to provide data on intense sweetener consumption patterns and to identify sub-groups of the population at risk of exceeding the ADI for individual intense sweeteners. The survey was conducted via telephone to determine patterns of consumption of 12 key food groups containing intense sweeteners and to screen respondents in order to select high consumers of intense sweeteners. Exposure to intense sweeteners in high consumers was estimated from diary surveys.
The two main food groups contributing to intense sweetener exposure in the survey were carbonated soft drinks (27%) and confectionery (27%). Thirteen per cent of respondents had consumed flavoured yoghurt/mousses, 10% had consumed tabletop sweeteners, 8% had consumed cordials and 7% ice cream. In comparison with the 1994 survey, there has been a significant increase in the consumption of carbonated soft drinks, cordial and flavoured yoghurt/mousses containing intense sweeteners. The report states that despite the increased consumption of foods containing intense sweeteners, the majority of Australians consume these foods in amounts that present no safety risk.
Women, people with diabetes and those on weight management diets were more likely to consume intense sweeteners than others. Younger age groups were more likely to have consumed cordials, fruit drinks and confectionery containing intense sweeteners than the older age groups. Those aged 60 years and over were more likely to have consumed jam, canned fruit and tabletop sweeteners containing intense sweeteners.
The mean exposure to all intense sweeteners surveyed was below their ADI. Exposure in relation to each ADI was highest for cyclamate with some consumers exceeding the cyclamate ADI. Cordials, fruit drinks and carbonated soft drinks were the major contributors to cyclamate exposure. To address over-consumption of cyclamate, FSANZ has reduced the maximum amount of cyclamates allowed in flavoured drinks.
Information on consumption of steviol glycosides in Australia is not yet available, due to its more recent introduction to the market.
Intense sweeteners and weight management
Intense sweeteners or ‘diet’ foods are often chosen to maintain or lose weight, however, research suggests that intense sweeteners may actually contribute to weight gain. Several large population studies found a positive association between intense sweetener use and weight gain. These findings may be due to overcompensation when substituting intense sweeteners for sugar, resulting in an overall increase in total energy intake. Results from a recent meta-analysis showed that findings from observational studies showed no association or a small positive association between intense sweetener use and weight gain. However, data from randomised controlled trials, which provide the highest quality of evidence, indicate that substituting intense sweeteners for sugar results in modest weight loss. Given the evidence on the effectiveness of intense sweeteners for weight management is mixed, Cancer Council does not recommend substitution with intense sweeteners, particularly in discretionary foods such as soft drinks and confectionery, as a way of reducing obesity-related cancers.
Guidelines for a healthy diet
Cancer Council encourages healthy eating and maintaining a healthy weight to help protect against cancer. Cancer Council supports the Australian Dietary Guidelines that recommend people be physically active and choose amounts of nutritious food and drinks to meet energy needs. A healthy diet includes plenty of vegetables, fruit, grain foods (wholegrain), moderate amounts of lean meats, poultry and fish, and dairy products.
Information sheet details
This information sheet was reviewed and approved by the Public Health Committee August 2015.
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