GENEVA, SWITZERLAND: A semi-independent committee for the World Health Organization (WHO) has categorized aspartame, a popular artificial sweetener found in thousands of products like diet sodas, as “possibly carcinogenic to humans.” WHO’s International Agency for Research on Cancer (IARC) announced on Thursday, July 13 that their researchers have identified a possible link between aspartame and a type of liver cancer called hepatocellular carcinoma.
The researchers classified aspartame as a possible carcinogen after examining three sizable human studies undertaken in the US and Europe that evaluated artificially sweetened beverages. These three studies could have been affected by bias, chance, or other issues, noted Dr. Mary Schubauer-Berigan, a senior official at IARC. She further emphasized that additional studies are required to evaluate whether consuming the artificial sweetener actually causes cancer because the categorization is based on scant evidence.
Given the limited evidence, the Joint Expert Committee on Food Additives concluded that the classification does not change the recommended limit on the daily intake of the artificial sweetener, according to CNBC. The FDA also reviewed the evidence and, according to a spokesperson, they identified significant flaws in the IARC's study. Therefore, the spokesperson stated, “FDA scientists do not have safety concerns when aspartame is used under the approved conditions.”
What is Aspartame?
Known for its low-calorie and sugar-free properties, aspartame is a sugar substitute, which is used in Diet Coke, Pepsi Zero Sugar, and other diet sodas, as well as some chewing gum and various Snapple drinks. The artificial sweetener was approved for use as a sweetener in the US by the Food and Drug Administration in 1974. However, the decision was put on hold due to a study that linked it to brain tumors. The FDA concluded that this link likely did not exist and allowed sales of the product in 1981. Coca-Cola started adding artificial sweeteners to Diet Coke in the 1980s and popularised the calorie-free beverage with eye-catching advertising campaigns that emphasized its flavor. Despite its widespread use, there have always been skeptics and detractors, and recent studies indicate that artificial sweeteners may change the microbiota and enhance food cravings in some individuals.
WHO’s latest classification came after two separate committees examined the evidence on aspartame. The IARC used a classification system to rank the potential of aspartame to cause cancer in humans, landing on 2B, which translates to it being a "possible carcinogen" along with aloe vera extract. In addition to the previous three studies, the committee also reviewed the data from a significant French research, the NutriNet-Santé study, which was published in 2022 and found that people who consumed the most aspartame had an increased risk of cancer, including breast and obesity-related cancers, compared with people who didn't consume aspartame.
The research group said that these were "high-quality" studies, but it was unable to prove that aspartame was to blame for the spike in cancer cases since it could not completely rule out the possibility that the findings weren't due to chance, bias, or "confounding variables,'' The data was also examined by a second group, the Joint Expert Group on Food Additives, or JECFA, which concluded that "there is insufficient evidence to conclude that aspartame consumption is associated with cancer in humans,” according to a summary released by the WHO.
Is Aspartame safe for consumption?
WHO’s experts pointed out that the recommended daily consumption amounts of aspartame should not change in light of the contradictory findings. "Our results do not indicate that occasional consumption should pose a risk to most consumers," said Dr. Francesco Branca, director of the Department of Nutrition and Food Safety at the WHO, during a press conference in Geneva. He noted that it is a red flag for "high consumers" of diet soda or other foods that contain aspartame. "We have, in a sense, raised a flag here," Branca said, while calling for more thorough studies, NPR reported.
The acceptable daily intake, or ADI, of aspartame, has long been determined by the WHO as a maximum of 40 milligrams per kilogram of body weight each day. This means that a person weighing 60 kilograms (approximately 130 pounds) could consume up to 2,400 milligrams per day, which is roughly equivalent to 12 cans of Diet Coke — much higher than most people consume. While the WHO is not revising the acceptable daily intake of aspartame, Branca said "We're just advising for a bit of moderation." He continued by adding that "the benefit is not there" if people use aspartame to avoid sweets and manage their weight.
