Aspartame “possibly carcinogenic to humans”, confirms WHO

After recent headlines that aspartame, a popular non-sugar sweetener used in food and beverage products, may have food safety risks, the World Health Organization has confirmed that it is “possibly carcinogenic to humans”.

The assessment was released by International Agency for Research on Cancer (IARC) and the World Health Organization (WHO) and the Food and Agriculture Organization (FAO) Joint Expert Committee on Food Additives (JECFA).

The IARC has said that there is “limited evidence” for carcinogenicity in humans, but has classified aspartame as possibly carcinogenic to humans (IARC Group 2B). What’s more the JECFA reaffirmed the acceptable daily intake of 40 mg/kg body weight.

Previously, New Food reported on plans for the sweetener to be “declared a possible carcinogen”, with the assessment now confirming its safety status.

Aspartame is an artificial sweetener that is used in a variety of food and beverage products, including diet drinks, ice cream and chewing gum. WHO has said that this sweetener has been used since the 1980s.

Commenting on the announcement, Dr Francesco Branca, Director of the Department of Nutrition and Food Safety, WHO, said: “Cancer is one of the leading causes of death globally. Every year, one in six 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.

“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.”

To carry out the study, two bodies conducted “independent but complementary reviews to assess the potential carcinogenic hazard and other health risks associated with aspartame consumption”. While JECFA has now evaluated aspartame three times, this assessment was the first time that the IARC has carried out an investigation on the sweetener. However, both evaluations noted “limitations in the available evidence for cancer (and other health effects)”.

IARC has defined aspartame as “possibly carcinogenic to humans (Group 2B) on the basis of limited evidence for cancer in humans (specifically, for hepatocellular carcinoma, which is a type of liver cancer)”. It highlighted that there was “limited evidence for cancer in experimental animals and limited evidence related to the possible mechanisms for causing cancer”.

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Meanwhile, JECFA found that the data showed “no sufficient reason to change the previously established acceptable daily intake (ADI) of 0–40 mg/kg body weight for aspartame”. With this in mind, the Committee has reaffirmed that “it is safe for a person to consume within this limit per day.

“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,” said Dr Mary Schubauer-Berigan of the IARC Monographs programme.

Also commenting on the findings of the investigation, Dr Moez Sanaa, WHO’s Head of the Standards and Scientific Advice on Food and Nutrition Unit, said: “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.

 “We need better studies with longer follow-up and repeated dietary questionnaires in existing cohorts. We need randomized controlled trials, including studies of mechanistic pathways relevant to insulin regulation, metabolic syndrome and diabetes, particularly as related to carcinogenicity.”

Going forward, WHO and IARC have said that they will continue to monitor new evidence. They are also encouraging independent research groups to carry out further studies on the potential association between aspartame exposure and consumer health effects.