The World Health Organization's International Agency for Research on Cancer (IARC) will announce next month that the artificial sweetener aspartame "is possibly carcinogenic to humans,” two sources close to the matter told Reuters. 

The decision by the international agency was based on 130 studies. The Aspartame artificial sweetener can be found in many "sugar-free" or "diet" products. Their announcement would link the substance to possibly causing cancer.

The subject has been a heated topic of research. Last year, an observational study of 100,000 adults in France showed that people who consumed larger quantities of artificial sweeteners, including aspartame, had a slightly higher risk of cancer.

It followed an early 2000s study by the Ramazzini Institute, in Italy, which reported that certain cancers in mice and rats were linked to aspartame. Its use was authorized worldwide by regulators, who claim to have examined all available evidence to date, while major food and beverage manufacturers have defended their use of the ingredient for decades.

According to sources close to IARC, this listing of aspartame as a possible carcinogen is intended to motivate more research in order to help agencies, consumers and manufacturers draw more solid conclusions. However, the food industry has prepared their counter-offensive, starting by questioning the role and credentials of this body. 

"IARC is not a food safety agency and its review of aspartame is not scientifically comprehensive and is based largely on largely discredited research," said Frances Hunt-Wood, Secretary General of the International Sweeteners Association.

Last month, the WHO warned against the use of artificial sweeteners, this time noting that prolonged consumption of artificial sweeteners can increase the risk of type 2 diabetes and heart and blood vessel disease, as well as the mortality rate among users.