WHO suggested aspartame has no adverse effect when consumed within acceptable daily intake limit of 40 mg/kg of body weight.
Published Jul 15, 2023 | 10:13 AM ⚊ Updated Jul 16, 2023 | 2:49 AM
Due to "limited evidence" of carcinogenicity in humans, IARC classified aspartame as "possibly carcinogenic to humans. (Creative Commons)
Is aspartame, a commonly used artificial sweetener, carcinogenic? Expert bodies conducted various tests, and found no specific evidence, compelling them to classify the artificial non-saccharide sweetener as “possibly carcinogenic to humans”.
The Expert Committee on Food Additives, the International Agency for Research on Cancer (IARC), and the Joint Expert Committee on Food Additives (JECFA) of the World Health Organisation (WHO) and the Food and Agriculture Organisation (FAO) conducted a thorough review of aspartame.
They found no compelling evidence, from human or animal studies, to suggest that aspartame has adverse effects when consumed within the acceptable daily intake limit of 40 milligrams per kilogram of body weight.
Dr Francesco Branca, the director of WHO’s Department of Nutrition and Food Safety, told a news conference on Thursday, 13 July, that the conclusion was reached after analysing recent studies that presented conflicting results regarding the potentially toxic effects of aspartame.
Due to “limited evidence” of carcinogenicity in humans, IARC classified aspartame as “possibly carcinogenic to humans” (Group 2B), while JECFA reaffirmed the acceptable daily intake of 40 mg/kg of body weight.
Aspartame is widely used in various food and beverage products since the 1980s, including diet drinks, chewing gum, gelatin, ice cream, dairy products, breakfast cereal, toothpaste, and medications.
Dr Branca emphasised the importance of addressing cancer, a leading cause of death globally, and the ongoing scientific efforts to identify factors that may contribute to its development.
“The assessments of aspartame have indicated that, while safety is not a major concern at the doses which are commonly used, potential effects have been described that need to be investigated by more and better studies,” he added.
Both IARC and JECFA conducted independent yet complementary reviews to evaluate the potential hazards of aspartame, including its carcinogenic effects and other health risks. This was the first time IARC evaluated aspartame, while JECFA assessed it on two previous occasions.
After reviewing the available scientific literature, both evaluations noted limitations in the available evidence for cancer (and other health effects).
IARC classified aspartame as “possibly carcinogenic to humans” (Group 2B) due to limited evidence of cancer in humans, specifically hepatocellular carcinoma, a form of liver cancer. Limited evidence of cancer in experimental animals and possible mechanisms for causing cancer were also observed.
JECFA concluded that the data reviewed did not provide sufficient grounds to modify the previously established acceptable daily intake (ADI) of 0–40 mg/kg body weight for aspartame.
Consequently, the committee reaffirmed that aspartame is safe for daily consumption within this limit.
For instance, an adult weighing 70 kg would need to consume between nine and 14 cans of diet soft drinks containing 200 or 300 mg of aspartame per day to exceed the acceptable daily intake, assuming no other significant intake from other food sources.
It is important to note that IARC’s hazard identifications represent the initial step in understanding an agent’s carcinogenicity by identifying its specific properties and potential to cause harm.
The classifications reflect the strength of scientific evidence regarding an agent’s ability to induce cancer in humans, but they do not indicate the risk of developing cancer at a given level of exposure.
Group 2B, the classification for aspartame, indicates limited evidence for cancer in humans or convincing evidence in experimental animals but not both.
“The findings of limited evidence of carcinogenicity in humans and animals, and of limited mechanistic evidence on how carcinogenicity may occur, underscore the need for more research to refine our understanding on whether consumption of aspartame poses a carcinogenic hazard,” Dr. Mary Schubauer-Berigan of the IARC Monographs programme, stated.
JECFA’s risk assessments focus on determining the probability of specific harms, such as cancer, occurring under certain conditions and levels of exposure. It is not uncommon for JECFA to consider IARC classifications in its deliberations.
Dr Moez Sanaa, WHO’s Head of the Standards and Scientific Advice on Food and Nutrition Unit stated that JECFA also evaluated the evidence on cancer risk in animal and human studies and found no convincing association between aspartame consumption and cancer in humans.
“We need better studies with longer follow-up and repeated dietary questionnaires in existing cohorts. We need randomised controlled trials, including studies of mechanistic pathways relevant to insulin regulation, metabolic syndrome, and diabetes, particularly as related to carcinogenicity,” Dr. Sanaa said.
The evaluations conducted by IARC and JECFA regarding the impact of aspartame were based on scientific data gathered from various sources, including peer-reviewed papers, government reports, and studies carried out for regulatory purposes.
Independent experts reviewed these studies, and both committees took steps to ensure the independence and reliability of their evaluations.
IARC and WHO will continue to monitor new evidence and encourage independent research groups to conduct further studies on the potential association between aspartame exposure and its effects on consumer health.
