WHO is set to release new data on Friday, 14 July on the carcinogenic risks of consuming aspartame, the artificial sweetener that is omnipresent in low-calorie soft-drinks, sweets and other processed foods, its head of nutrition, Dr Francesco Branca confirmed on Wednesday. 

A full WHO risk assessment on safe levels of exposure to the sugar substitute, which hasn’t been assessed since 1981, is due to be completed this week by the WHO and Food and Agriculture Organization’s Joint Expert Committee on Food Additives (JECFA), Branca said, speaking at a WHO press briefing on Wednesday. 

“The assessment of aspartame has been,in the first place, a hazard identification process. This has been closed. This is now followed by a full risk assessment process,” Branca said. “The two assessments will be then put together in a final release that will be completed and disseminated next week – a full risk assessment will be available next week.”

His comment came days after a Reuters report stated that aspartame is set to be declared as “possibly carcinogenic to humans”, by the International Agency for Research on Cancer (IARC), a WHO-affiliated agency that recently completed a separate assessment process on the sweetener. 

The new IARC monograph is due to be released 14 July, simultaneously with the JECFA assessment.  

IARC’s assessments looks at carcinogenicity, WHO evaluates exposure risks 

While IARC’s assessments look at whether a substance is potentially hazardous, or not, the JECFA assessments look at how much, if any, of a product is actually safe to consume, a WHO spokesperson explained, in a comment to Health Policy Watch.  

“In its Monographs Programme, IARC conducts hazard identification, which is the first fundamental step to understand carcinogenicity. Hazard identification aims to identify the specific properties of the agent and its potential to cause harm, i.e., the potential of an agent to cause cancer. 

“The classifications reflect the strength of the scientific evidence as to whether an agent can cause cancer in humans, but they do not reflect how high the risk of developing cancer is at a given exposure level.

“The JECFA Programme (Joint FAO/WHO Expert Committee on Food Additives) conducts risk assessment, which determines the probability of a specific type of harm (e.g., cancer) to occur under certain conditions and levels of exposure.  

“The evaluations are independent but complementary and are conducted one after the other in the months of June-July 2023,” the spokesperson explained. 

“Given the close collaboration between the IARC Monographs and the WHO/FAO JECFA Secretariat, we have planned to present the results of both evaluations at the same time.” This will allow to clearly communicate the different purposes of a hazard 

Aspartame’s links with health conditions

Along with cancer, aspartame has in the past been linked to a wide range of serious health conditions. A 2 July roundup by the US-based public health group, Right to Know, cites evidence around the sweetener’s links to cardiovascular disease, Alzheimer’s seizures, stroke and dementia, along with a range of head, stomach and mood disorders, and even weight gain. 

In May 2023, the World Health Organization signaled a change in its policies, advising the public not to consume non-sugar sweeteners for weight loss, including aspartame. The recommendation was based on a systematic review of the most current scientific evidence, which suggests that consumption of non-sugar sweeteners is in fact associated with increased risk of type 2 diabetes, cardiovascular diseases and all-cause mortality, as well as increased body weight.

Even so, evaluations by the US Food and Drug Administration (FDA), and the European Food Safety Authority have so far rebuffed claims that there is significant evidence of health risks. The FDA states that aspartame is “safe for the general population under certain conditions of use.

A “possibly carcinogenic to humans” IARC classification, which is the classification reportedly assigned to aspartame, is the lowest cancer classification level on the agency’s scale – other than “not classifiable at all”. 

It means that there is some limited evidence that the additive causes cancer in humans. 

“Probably carcinogenic” is the next step in the scale – in which red meat belongs along with glyphosate, the widely used weedkiller, first marketed by Monsanto and now controlled by Bayer. 

Substances with the most robust evidence receive the highest classification – “carcinogenic”.  Those range from outdoor air pollution and diesel exhaust to processed meat and asbestos. All have convincing evidence showing they cause cancer, IARC says.

National regulatory agencies have not always followed IARC’s recommendations.  For instance, the US Environmental Protection Agency still considers glyphosate to be “not likely to be carcinogenic in humans.”

Image Credits: Maxwildcat, CC BY-SA 4.0.