The Curious Case of Aspartame: How the Same Evidence Can Yield Seemingly Different Conclusions
Food and Drug Law Institute, January 2024
In July 2023, the World Health Organization’s International Agency for Research on Cancer (IARC) classified the artificial sweetener aspartame as “possibly carcinogenic” to humans. That same day, the US Food and Drug Administration (FDA) released a statement reaffirming its position that aspartame is safe to consume. How did the two agencies come to such seemingly disparate conclusions? In the article “The Curious Case of Aspartame: How the Same Evidence Can Yield Seemingly Different Conclusions,” published by the Food and Drug Law Institute, Analysis Group authors examine how the distinct mandates of the IARC and the FDA shaped the different ways that the two bodies conveyed information about the safety of aspartame consumption, despite their agreement on the limitations of the available scientific evidence.
The authors – Managing Principal Jee-Yeon Lehmann, Principal Brian Ellman, Analyst Jack Pfefferkorn, and affiliate Christopher M. Worsham (Harvard Medical School, Massachusetts General Hospital) – first explain how the different organizational aims of the IARC (to identify potential cancer hazards) and the FDA (to regulate food safety and issue health guidance) led the organizations to reach different conclusions. They then describe how both qualified their conclusions by recognizing and explaining the limitations of the available scientific evidence. In closing, the authors discuss the importance of using high-quality evidence to reach conclusions regarding the causal relationship between product exposure and health outcomes.