WHO studies flag sweetener ‘aspartame’ as ‘possibly carcinogenic’

The World Health Organisation (WHO) has flagged the studies related to ‘aspartame’, which lebelled it “possibly carcinogenic to humans”, raising doubts over the use of one of the world’s most common artificial sweeteners used in everything from diet drinks to yogurt to toothpaste.

However, the WHO clarified that the International Agency for Research on Cancer (IARC), in its recent studies, found there’s “limited evidence” for carcinogenicity in humans when it comes to aspartame.

“Citing “limited evidence” for carcinogenicity in humans, IARC classified aspartame as possibly carcinogenic to humans (IARC Group 2B) and JECFA reaffirmed the acceptable daily intake of 40 mg/kg body weight,” the global health body says in its latest assessment report.

Notably, aspartame is an artificial chemical sweetener widely used in various food and beverage products since the 1980s, including diet drinks, chewing gum, gelatin, ice cream, dairy products such as yogurt, breakfast cereal, toothpaste, and medications such as cough drops and chewable vitamins.

The WHO says cancer is one of the leading causes of death globally, and that these claims need to be investigated by more and better studies.

“Every year, 1 in 6 people die from cancer. Science is continuously expanding to assess the possible initiating or facilitating factors of cancer, in the hope of reducing these numbers and the human toll,” said Dr Francesco Branca, Director of the Department of Nutrition and Food Safety, WHO.

Dr Branca says the assessments of aspartame have indicated that, while safety is not a major concern at the doses which are commonly used, “potential effects need to be investigated by more and better studies.”

The two bodies, IARC and the Food and Agriculture Organisation (FAO) Joint Expert Committee on Food Additives (JECFA), had conducted independent but complementary reviews on aspartame consumption.

The WHO says this was the first time IARC evaluated aspartame and the third time for JECFA.

Both evaluations noted limitations in the available evidence for cancer (and other health effects), though IARC classified aspartame as “possibly carcinogenic to humans”, specifically, for “hepatocellular carcinoma”, a type of liver cancer.

The WHO found there was also “limited evidence” for cancer in experimental animals and limited evidence related to the possible mechanisms for causing cancer.

JECFA says the data evaluated indicated no sufficient reason to change the previously established acceptable daily intake (ADI) of 0–40 mg/kg body weight for aspartame. “The committee, therefore, reaffirmed that it is safe for a person to consume within this limit per day.”

For example, with a can of diet soft drink containing 200 or 300 mg of aspartame, an adult weighing 70kg would need to consume more than 9–14 cans per day to exceed the acceptable daily intake, assuming no other intake from other food sources.

The WHO says JECFA’s risk assessments determine the probability of a specific type of harm, i.e. cancer, to occur under “certain conditions and levels of exposure”.

“JECFA also considered the evidence on cancer risk, in animal and human studies, and concluded that the evidence of an association between aspartame consumption and cancer in humans is not convincing,” said Dr Moez Sanaa, WHO’s head of the standards and scientific advice on food and nutrition unit.

The IARC and JECFA’s evaluations on aspartame were based on scientific data collected from a range of sources, including peer-reviewed papers, governmental reports, and studies conducted for regulatory purposes.