On July 13, the International Agency for Research on Cancer (IARC), an intergovernmental agency of the World Health Organization (WHO) and the Food and Agriculture Organization (FAO) Joint Expert Committee on Food Additives (JECFA) released their assessments of the health impacts of aspartame. This was the first occasion that IARC has evaluated aspartame and the third one for JECFA.
The IARC classified aspartame in Group 2B of its classification i.e. possibly carcinogenic to humans.
The JECFA concluded that there was insufficient evidence to change its previous acceptable daily aspartame intake of 0-40mg/kg body weight.
What are the implications of the announcement?
Sugar alternative
Aspartame is a popular non-sugar sweetener, which is not found naturally in food and has no nutritional value.
It provides a level of sweetness, without calories, in many foods and beverages.
It is found in tabletop sweeteners; beverages including diet drinks; gelatin; ice cream; chewing gum; dairy products like yoghurt, breakfast cereal; some medicines like cough drops and chewable vitamins; and toothpastes.
Previous research reports have associated aspartame with an increased risk of heart disease, high blood pressure, diabetes and obesity.
IARC classification
A carcinogen is a substance, organism or agent capable of causing cancer.
The IARC has three categories based on the certainty of the evidence of the risk.
They are:
> Group 1: Carcinogenic to humans – when there is sufficient evidence of carcinogenicity in humans or when there is both strong evidence in exposed humans that the agent exhibits key characteristics of carcinogens and sufficient evidence of carcinogenicity in experimental animals.
Examples include tobacco, ionising radiation, asbestos.
> Group 2A: Probably carcinogenic to humans when there is at least two of the following i.e. limited evidence of carcinogenicity in humans; sufficient evidence of carcinogenicity in experimental animals; strong evidence that the agent exhibits key characteristics of carcinogens.
Examples include biomass fuel (primarily wood), workplace exposure to petroleum refining.
> Group 2B: Possibly carcinogenic to humans when there is one of the following i.e. limited evidence of carcinogenicity in humans; sufficient evidence of carcinogenicity in experimental animals; strong evidence that the agent exhibits key characteristics of carcinogens.
Examples include aloe vera, pickled vegetables.
> Group 3: Agents that do not fall into any other group.
Placement in this group is not a determination of non-carcinogenicity or overall safety.
It often means that the agent is of unknown carcinogenic potential and that there are significant gaps in research.Aspartame and IARC classification
Aspartame’s Group 2B IARC classification means that the evidence link to cancer is “limited” in layman language.
A summary of the IARC’s working group’s evaluation, was published on July 13 2023 in Lancet Oncology.
The IARC classification was based on data from three studies assessing the link between aspartame intake and hepatocellular carcinoma, a primary liver cancer.
There was a large cohort study in 10 European countries that assessed the association of artificially sweetened beverages with hepatocellular carcinoma; a second study that pooled data from two large United States cohorts that investigated the association between artificially sweetened beverage consumption and liver cancer incidence by diabetes status; and another large US prospective cohort study that evaluated the association between artificially sweetened beverages and liver cancer mortality.
Among all three studies, positive associations between artificially sweetened beverage consumption and cancer incidence or cancer mortality were reported in the overall study population or in relevant subgroups.
All three studies were of high quality and controlled for many potential confounders.
However, the working group concluded that chance, bias, or confounding could not be ruled out with reasonable confidence in this set of studies.
Thus, the evidence for cancer in humans was deemed “limited” for hepatocellular carcinoma and “inadequate” for other cancer types.
The IARC evaluation also reported limited evidence for cancer in experimental animals and limited evidence related to the possible mechanisms for causing cancer.
Other views
Cancer Research UK, one of the world’s largest independent cancer research organisation, states: “There is no convincing evidence that artificial sweeteners such as aspartame cause cancer.
“You might have seen stories about artificial sweeteners and cancer on social media or the news.
“But studies in people do not show a link between aspartame and cancer.
“Ingredients in food and drink in the UK are tightly regulated. The European Food Safety Authority (EFSA) has set an acceptable daily intake (ADI) for aspartame.
“It equals around 14 cans of diet fizzy drink for a person who weighs around 70kg. This is more cans than most people would have in one day.”
The US Food and Drug Administration (FDA) stated: “Aspartame being labelled by IARC as ‘possibly carcinogenic to humans’ does not mean that aspartame is actually linked to cancer.
“The FDA disagrees with IARC’s conclusion that these studies support classifying aspartame as a possible carcinogen to humans.”
Health Canada stated: “An ADI of 40mg per kilogramme of body weight/day was established by Health Canada before aspartame was permitted for use as a food additive.
“An ADI is an estimate of the amount of a substance in food that can be consumed daily over a lifetime without presenting an appreciable risk to health.
“This ADI is recognised internationally and is the same as that established and recently re-affirmed by JECFA.
“Health Canada is reviewing the summary assessments by IARC and JECFA published on July 13, and will review the full reports for each assessment once they are released”
The EFSA stated: “EFSA’s scientists are currently re-evaluating the safety of two related food additives, the salt of aspartame–acesulfame (E 962) and neotame (E 961), considering all new data that may have become available since they were last evaluated either by EFSA or the European Scientific Committee on Food.
“All relevant new studies on aspartame that may have become available after the publication of our scientific opinion on aspartame in 2013 will be considered and integrated into our assessment of the salt of aspartame-acesulfame (E 962).
“We will also update our dietary exposure assessment of aspartame as part of our re-evaluation of the salt of aspartame-acesulfame (E 962)”
As of July 17, there has been no reported statement from Malaysian authorities.
What should one do?
This situation was not helped by media reports, prior to the IARC/WHO announcement, with headlines like “WHO may declare aspartame a cancer risk.”
The public should not be unduly worried about aspartame’s Group 2B classification as almost any evidence of carcinogenicity, however flawed, will put a substance in that category.
The new information may cause a change in habits and reduction in consumption of foods containing non-sugar sweeteners.
However, it would not be wise to consume foods that contain sugar, particularly as Malaysia has one of the highest sugar consumption per capita in the world.
Instead, it would be better to make healthier choices like consuming a diet comprising mostly plant products and minimally processed foods. The inclusion of some non-sugar sweeteners, within recommended limits, may be beneficial if it helps to decrease overall calorie intake.
The statement by Mary Schubauer-Berigan, IARC’s acting head, that the new classification “shouldn’t really be taken as a direct statement that indicates that there is a known cancer hazard from consuming aspartame. This is really more of a call to the research community to try to better clarify and understand the carcinogenic hazard that may or may not be posed by aspartame consumption” was reassuring.
To address this conundrum, a review of one’s diet and a discussion with one’s regular doctor would be helpful.
Dr Milton Lum is a past president of the Federation of Private Medical Practitioners Associations and the Malaysian Medical Association. For more information, email starhealth@thestar.com.my. The views expressed do not represent that of organisations that the writer is associated with. The information provided is for educational and communication purposes only, and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the reader’s own medical care. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.
Already a subscriber? Log in
Get 20% OFF The Star Digital Access
Cancel anytime. Ad-free. Unlimited access with perks.
