Aspartame sweetener used in Diet Coke a ‘possible cancer risk’ says WHO: reports

The International Agency for Research on Cancer (IARC), the cancer arm of the World Health Organization (WHO), recently indicated that aspartame – one of the world’s most common artificial sweeteners – will likely be declared a “possible carcinogen to humans.”

The move is expected to pit the global body against the food industry and regulators.

Aspartame ‘cancer’ fears

After several decades of research on artificial sweeteners to reduce obesity and diabetes rates, aspartame was discovered in 1965 and eventually brought to market in 1981.

Aspartame is between 150 and 200 times sweeter than sugar and, as a result, does not increase the caloric value of food and drink products.

Aspartame, used in products from Diet 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 IARC, Reuters reported, citing unnamed sources.

The IARC ruling, finalised 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.

It does not take into account how much of a product a person can safely consume. This advice for individuals comes from a separate WHO expert committee on food additives, known as JECFA (the Joint WHO and Food and Agriculture Organization’s Expert Committee on Food Additives), alongside determinations from national regulators.

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 to alternatives.

That has led to criticism that the IARC’s assessments can be confusing to the public.

JECFA, the WHO committee on additives, is also reviewing aspartame use this year. Its meeting began at the end of June and it is due to announce its findings on the same day that the IARC makes its decision – on July 14.

The Reuters report said 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 US and Japanese regulators seen by Reuters.

According to the US Food and Drug Administration (FDA), the acceptable daily intake (ADI) for aspartame is 50 mg/kg, whereas European regulatory bodies recommend an ADI of 40 mg/kg for aspartame for both adults and children.

Throughout the world, aspartame can be found in more than 6,000 products, including food and beverages, cough drops, and some toothpaste, thus indicating the ubiquitous nature of this chemical in many everyday items.

Several studies have investigated the carcinogenic potential of aspartame. For example, one study in rats found that aspartame exposure early in life increased the risk that rat pups subsequently developed cancer.

The vast number of in vivo and in vitro studies indicating a potential role of aspartame in the development of cancer has led many regulatory agencies, like IARC, to reconsider the safety of aspartame for human consumption.

Likewise, the results from these studies have also supported human studies, which are largely scarce.