In July, the International Agency for Research on Cancer (IARC), a subsidiary of the World Health Organization (WHO), is set to declare aspartame as a “possible carcinogen.” Aspartame is an artificial sweetener commonly used in sugar-free beverages, chewing gum, and yogurt. Its chemical name is methyl aspartyl phenylalanine, and it was discovered by scientists in 1965 during the development of an ulcer medication. Aspartame is approximately 200 times sweeter than regular sugar and is considered by the food industry as a sugar substitute due to its intense sweetness and nearly zero calorie content.
However, controversy surrounding the health effects of aspartame has persisted for decades. In terms of its carcinogenicity, the Center for Science in the Public Interest (CSPI) in the United States declared in 2013 that animal studies have found a potential link between aspartame and cancers such as leukemia and lymphoma, and it should not be present in the food supply. However, previous assessments by organizations such as the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the U.S. Food and Drug Administration (FDA) concluded that aspartame does not have carcinogenic effects on animals. The American Cancer Society has also stated that multiple human studies have found no association between aspartame and an increased risk of cancer.
A study released by the European Ramazzini Foundation in 2006 reported that long-term consumption of aspartame at a dose of 100 milligrams per kilogram of body weight in laboratory mice resulted in various cancers, including lymphomas, leukemia, and neuroblastomas. However, the original data of this study were reviewed by relevant agencies commissioned by the United States and the European Union, which disputed the interpretation of the results and did not recognize the carcinogenicity of aspartame.
In terms of neurotoxicity, although reports suggest that high doses of aspartame in animals may alter neurotransmitter levels in the central nervous system, extensive animal experiments and epidemiological data have not shown any neurological diseases or symptoms related to aspartame consumption. Genetic toxicity studies have not found evidence that aspartame causes mutations, and no teratogenic or reproductive toxic effects have been observed.
Furthermore, some experts argue that while aspartame may lack the calorie content of sugar, it may still contribute to an increased risk of obesity.
In May of this year, the World Health Organization released new guidelines on non-sugar sweeteners, advising against the use of aspartame, acesulfame, saccharin, and other sweeteners for weight control or reducing the risk of non-communicable diseases. The WHO stated that a systematic review of the existing evidence indicates no long-term benefits in reducing body fat for adults or children through the use of non-sugar sweeteners. Long-term use of non-sugar sweeteners may carry potential adverse effects, such as an increased risk of type 2 diabetes, cardiovascular diseases, and adult mortality.