• Sucralose is a no calorie sweetener which has been deemed as safe and approved for use in food and drink products in the European Union. 
  • The authors of a study carried out in 2005 in mice (published in 2016) have suggested a link between the consumption of sucralose and cancer.
  • The European Food Safety Authority (EFSA)’s Panel on Food Additives and Nutrient Sources added to Food reviewed the study and found several problems with the methodology used which makes the results misleading.
  • EFSA concluded that the results do not demonstrate that sucralose causes cancer.

 

Sucralose (E955) is a no calorie sweetener approximately 600 times sweeter than sucrose which is authorised for use in food and drink products in the EU. Sucralose was assessed by the European Union Scientific Committee on Food in 2000 and the acceptable daily intake (ADI) was set at 15 mg/kg body weight. The ADI was based on a no observed effect level (an exposure level at which there are no statistically or biologically significant increases in the frequency or severity of any effect between the exposed population and its appropriate control) of 1,500 mg/kg body weight, based on a long term study in rats, and applying a 100-fold safety factor.

In 2016 the European Food Safety Authority (EFSA)’s Panel on Food Additives and Nutrient Sources added to Food (ANS Panel) concluded that the proposed extension of use for sucralose in foods for special medical purposes for young children aged from 1 to 3 years would not be of safety concern. As sucralose is part of a group of additives that were permitted for use in the EU before 2009, it will be re-assessed by EFSA by 2020 but authorised food additives are kept under continuous observation. The EC requested that EFSA provided an Opinion on an animal study published in 2016 performed by the Ramazzini Institute which concluded that sucralose induced cancer in male mice.

Study design

The study was carried out between 2005 and 2008 and published in the International Journal of Occupational and Environmental Health (Soffritti et al., 2016). Mice were exposed to sucralose, which was incorporated into feeding pellets in 5 different doses (0, 500, 2,000, 8,000 and 16,000 mg/kg diet; approximately equivalent to 0, 62.5, 250, 1,000 and 2,000 mg/kg body weight based on average body weight and feed consumption), from the 12th day of pregnancy (i.e. exposure in the womb) until either death or 130 weeks of age, at which time disease was assessed. 

Results as reported by the Ramazzini Institute

  • Survival was significantly lower among male animals on two of the sucralose doses (2,000 mg/kg diet and 16,000 mg/kg diet).
  • There was an increased incidence in tumours (mostly leukaemia) in male animals only, on the 2,000 mg/kg and 16,000 mg/kg sucralose diets.
  • The authors concluded that sucralose administered in feed induces tumours in male mice and that follow-up studies are urgently required.

EFSA identified several anomalies with the results:

  • The study only reported an effect in male mice and not female mice. No explanation was provided by the authors as to why sucralose would induce tumours in males and not females. Background data on the particular mice used suggests that female animals are more prone to developing leukaemia than male animals, which opposes the results of Soffritti et al., 2016. Therefore the plausibility of the proposed effect is low and a mechanism of action is lacking.
  • An increase in tumour rate was found at 2,000 mg/kg and 16,000 mg/kg but not the 8,000 mg/kg dose, therefore the data does not demonstrate a dose-response relationship.
  • There is no reliable evidence in the wider literature that sucralose can induce genetic mutations.

The ANS Panel had several comments on the methodology used to carry out the study and the data obtained, including:

  • Several aspects of the study design deviate from standard guidelines and the lab was not accredited at the time the study was carried out.
  • Following the animals for such a lengthy duration is not standard practice and may have confounded the results as cancer risk increases in later life.
  • The stability of sucralose in the food pellets over time was not demonstrated.
  • The method of allocating the mice to different treatment groups was insufficiently explained.
  • The control animals were not housed with the intervention animals, therefore the environmental conditions of the two groups differed.
  • The data indicates overall health issues with the animals bred during the study, such as a high incidence of lung inflammation in all groups (particularly the controls). The ANS Panel suggests that cases of lung inflammation could have been misdiagnosed as leukaemia.

The ANS Panel therefore disagreed with the authors’ conclusions. It highlighted that studies carried out according to standard guidelines and protocols have not demonstrated that sucralose causes cancer, even at high doses up to 30,000 mg/kg diet.

Conclusion

The ANS Panel concluded the available data did not support the suggestion that sucralose induces tumours in male mice.

Furthermore, it is worth noting that the lowest dose of sucralose used in this study which was suggested to induce tumours (2,000 mg/kg diet, equivalent to 250 mg/kg body weight) is more than sixteen times higher than the European ADI of 15 mg/kg body weight.

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