A common artificial sweetener found in everything from soft drinks to yoghurt is expected to be labelled a possible carcinogen next month – but experts say you don’t need to throw away your Diet Coke just yet.

The World Health Organisation’s (WHO) International Agency for Research on Cancer (IARC) has assessed the potential carcinogenic effect of aspartame, and reports indicate the additive has been found to possibly cause cancer in humans.

IARC will officially reveal the results of its assessment on July 14; at the same time, the Joint Food and Agriculture Organisation/WHO Expert Committee on Food Additives (JECFA) will provide an update as to whether there will be any changes to the acceptable daily intake and dietary exposure to aspartame.

Michael Cawley, Monash University physiology professor, said until the results of the assessments by IARC and JECFA are officially announced, reports of aspartame being labelled a carcinogen are just speculation.

But even if aspartame is labelled possibly carcinogenic, there’s no need to panic.

Understand risks

Professor Cawley said people are exposed to possible carcinogens every day, and that doesn’t mean everyone will definitely get cancer.

“The World Health Organisation says that red meat is possibly related to cancer … many things that we can’t avoid in our lives are possibly related to cancer,” he said.

“We know that sunlight causes cancer, and yet many of us tan … consuming alcohol may cause cancer.

“Everything has a risk of cancer. Life is about balancing risks.”

He said people tend to be really bad at understanding risk.

For example, people are scared of flying in planes because of the one fatal crash that occurs every 3.7 million flights; meanwhile, many of those people are likely perfectly comfortable to get in a car despite the fatality rate of crashes in Australia sitting at 4.4 per 100,000 people in 2021.

“Risk is a really difficult thing for … doctors to assess, it’s even harder for the general public to assess, and so that’s why we need to be really careful about how we discuss this sort of thing because risk is relative,” Professor Cawley said.

Previous studies

This isn’t the first time the potential health risks posed by aspartame have been studied.

A 2022 study found artificial sweeteners, including aspartame, were associated with increased cancer risk – particularly breast and obesity-related cancers, such as colorectal, stomach and prostate cancers.

This is because aspartame turns into the known carcinogen formaldehyde when digested, potentially causing the body’s cells to become cancerous, and switching off genes that would otherwise cause cancer cells to self-destruct.

Another study found the consumption of large amounts of aspartame could lead to a higher risk of stroke.

Reduce sweets consumption

Professor Cawley said the best preventative measure would be to reduce your overall intake of sweet foods and drinks.

“People have thought that sugar causes health problems because it’s high in caloric value, and so … consuming too much sugar increased risk of diabetes,” he said.

“And so we’ve made this switch in our minds that we’ll take that and exchange it for artificial sweeteners or non-nutritive sweeteners like sucralose, or aspartame … and that’s a free pass to have that sweet flavour in our life without any risk of the disease.

“We’re now learning that these compounds may have a risk that’s different to the risk of sugar … but still carries risk. So I think a better solution is to just decrease the amount of sweet things we eat.”

Authority keeps watch

The Food Standards Australia New Zealand (FSANZ) website notes that in 1980 JECFA established an acceptable daily intake (ADI) for aspartame of 40mg per kg of body weight.

The ADI is the amount of a food additive that can be consumed each day over your entire life without any significant health risks.

Christel Leemhuis, general manager science and risk assessment at FSANZ, told TND the organisation is closely monitoring the IARC and JECFA outcome.

Experts from FSANZ are currently assisting in JECFA’s assessment of aspartame.

“FSANZ looks to JECFA in terms of its assessment of [aspartame] … from the food perspective. That’s the body we will look to in terms of any action, if any, that’s required,” Ms Leemhuis said.

“It’s really important to note, it’s not just if something is carcinogenic, it’s actually how much we get of that.

“We’ll take any action that’s needed, but … aspartame has been evaluated numerous times internationally and over many years, and still is considered to be safe at the current permitted levels.”