Artificial Sweetener Aspartame Under Scrutiny for Cancer Risk

One of the most commonly used artificial sweeteners in the world, aspartame, is set to be labeled as a possible carcinogen by the International Agency for Research on Cancer (IARC), the cancer research arm of the World Health Organization (WHO). This upcoming classification published by Reuters has created a rift between the food industry, regulators, and health experts. While the IARC’s assessment aims to identify potential hazards based on published evidence, it does not consider safe consumption limits. The decision, expected to be announced on July 14, has raised concerns among consumers, led to lawsuits, and put pressure on manufacturers to seek alternatives. 

The Joint WHO and Food and Agriculture Organization’s Expert Committee on Food Additives (JECFA) has long considered aspartame safe for consumption within established daily limits. National regulators, including those in the United States and Europe, have supported this view. However, the IARC’s impending ruling challenges the existing consensus. The IARC spokesperson emphasized that the findings of both the IARC and JECFA committees are complementary but confidential until July. 

The simultaneous review of aspartame by both the IARC and JECFA has raised concerns among industry representatives and regulators. They fear that the coordination of these processes could cause confusion among the public. A letter from Japan’s Ministry of Health, Labour, and Welfare urged the organizations to align their efforts and release their conclusions on the same day. The impact of previous IARC rulings, such as the classification of glyphosate as “probably carcinogenic,” has made industry stakeholders apprehensive about potential repercussions. 

The IARC’s decision-making process has faced criticism for generating unnecessary alarm and confusion. The agency classifies substances into four levels: carcinogenic, probably carcinogenic, possibly carcinogenic, and not classifiable. Critics argue that these classifications do not adequately reflect the actual danger posed by a substance. While the IARC’s assessments are based on the strength of the evidence, other organizations may contest these findings, as seen in the case of glyphosate. The upcoming aspartame classification is likely to reignite debates over the IARC’s role and the safety of sweeteners in general. 

Scientific studies on aspartame have been conducted for years. An observational study in France suggested a slightly higher cancer risk among individuals who consumed larger amounts of artificial sweeteners, including aspartame. However, this study did not establish a causal relationship. The methodology of an earlier study linking aspartame to cancer in mice and rats has also been questioned. Despite these studies, regulators globally have authorized the use of aspartame based on their comprehensive reviews of available evidence. 

Industry giants, such as Coca-Cola and Mars, have staunchly defended the safety of aspartame, which has been extensively used in their products. However, some companies have made adjustments to their recipes in response to consumer concerns. Pepsico, for instance, removed aspartame from its sodas in 2015 but reintroduced it a year later. The ongoing debate surrounding aspartame’s safety may prompt further research and encourage agencies, consumers, and manufacturers to form more definitive conclusions. 

The upcoming classification of aspartame as a possible carcinogen by the IARC has set the stage for a heated debate among the food industry, regulators, and health experts. While the IARC’s assessment focuses on potential hazards based on published evidence, it does not consider safe consumption limits. Conflicting assessments from different organizations have created confusion among the public and raised concerns among industry stakeholders. Nevertheless, the classification is expected to spur further research and prompt discussions about the IARC’s role and the safety of artificial sweeteners.