Aspartame’s cancer risk unclear

July 24, 2023 – A recent report by the World Health Organization (WHO) declared that the artificial sweetener aspartame is “possibly carcinogenic,” but the research leading to that conclusion is unclear—so consuming aspartame to help with weight management is still reasonable, according to experts at Harvard T.H. Chan School of Public Health.

Evaluating existing research, WHO reclassified aspartame as possibly leading to cancer—but did not change its recommendation for acceptable daily intake of the sweetener. Additionally, in response to the WHO report, the U.S. Food and Drug Administration said that aspartame is safe to consume at currently recommended levels.

In a July 14 NPR article, Frank Hu, Fredrick J. Stare Professor of Nutrition and Epidemiology, said that the cancer risk of aspartame has not been well studied because it is hard to measure the exact amounts of sweetener that people consume. He also said that studying aspartame’s link with rare cancers such as liver cancer would require “hundreds of thousands of people, perhaps millions of people to be followed and to obtain sufficient statistical power to get reliable answers.”

Consuming aspartame in certain situations, such as drinking aspartame-containing diet sodas to help control weight, still makes sense, said Walter Willett, professor of epidemiology and nutrition, in a July 13 NPR article. Because sugary drinks can increase the risk of obesity and type 2 diabetes, “For people who are presently consuming diet soda, the worst possible decision would be to switch to regular sugar-sweetened soda,” he said. He added that while the best beverages for daily consumption are water, coffee, and tea, diet soda can help people transition from drinking sugar-sweetened sodas.

Read or listen to the July 13 NPR article: WHO says aspartame is a ‘possible carcinogen.’ The FDA disagrees

Read the July 14 NPR article: What you need to know about aspartame and cancer