One of the world’s most common artificial sweeteners is set to be declared a possible carcinogen next month by a leading global health body, according to two sources with knowledge of the process, pitting it against the food industry and regulators.
Aspartame, used in products from Coca-Cola diet sodas to Mars’ Extra chewing gum and some Snapple drinks, will be listed in July as “possibly carcinogenic to humans” for the first time by the International Agency for Research on Cancer (IARC), the World Health Organization‘s (WHO) cancer research arm, the sources said.
The IARC ruling, finalized earlier this month after a meeting of the group’s external experts, is intended to assess whether something is a potential hazard or not, based on all the published evidence.
However, similar IARC rulings in the past for different substances have raised concerns among consumers about their use, led to lawsuits, and pressured manufacturers to recreate recipes and swap for alternatives. That has led to criticism that the IARC’s assessments can be confusing to the public.
Since 1981, JECFA has said aspartame is safe to consume within accepted daily limits. For example, an adult weighing 60 kg (132 pounds) would have to drink between 12 and 36 cans of diet soda – depending on the amount of aspartame in the beverage – every day to be at risk. Its view has been widely shared by national regulators, including in the United States and Europe.
An IARC spokesperson said both the IARC and JECFA committees’ findings were confidential until July, but added they were “complementary”, with IARC’s conclusion representing “the first fundamental step to understand carcinogenicity”. The additives committee “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.”
However, industry and regulators fear that holding both processes at around the same time could be confusing, according to letters from U.S. and Japanese regulators seen by the leading news agency.
The IARC’s decisions have also faced criticism for sparking needless alarm over hard-to-avoid substances or situations. It has previously put working overnight and consuming red meat into its “probably cancer-causing” class, and using mobile phones as “possibly cancer-causing”, similar to aspartame.
Aspartame has been extensively studied for years. Last year, an observational study in France among 100,000 adults showed that people who consumed larger amounts of artificial sweeteners – including aspartame – had a slightly higher cancer risk, the Reuters report said.
However, the first study could not prove that aspartame caused the increased cancer risk, and questions have been raised about the methodology of the second study, including by EFSA, which assessed it. Aspartame is authorized for use globally by regulators who have reviewed all the available evidence, and major food and beverage makers have for decades defended their use of the ingredient. The IARC said it had assessed 1,300 studies in its June review.
Recent recipe tweaks by soft drinks giant PepsiCo demonstrate the struggle the industry has when it comes to balancing taste preferences with health concerns. PepsiCo removed aspartame from sodas in 2015, bringing it back a year later, only to remove it again in 2020. Listing aspartame as a possible carcinogen is intended to motivate more research, said the sources close to the IARC, which will help agencies, consumers, and manufacturers draw firmer conclusions.
But it will also likely ignite debate once again over the IARC’s role, as well as the safety of sweeteners more generally. Last month, the WHO published guidelines advising consumers not to use non-sugar sweeteners for weight control. The guidelines caused a furor in the food industry, which argues they can be helpful for consumers wanting to reduce the amount of sugar in their diet.
(With inputs from agencies)
