Dozens of studies have linked the widely used artificial sweetener aspartame to various severe health problems, including cancer, cardiovascular disease, Alzheimer’s disease, seizures, stroke, and dementia, as well as negative effects such as intestinal dysbiosis, mood disorders, headaches, and migraines. Furthermore, evidence suggests that aspartame is associated with weight gain, increased appetite, and obesity-related diseases, raising concerns about the marketing of aspartame-containing products as "diet" drinks or weight-loss aids.

In 2015, the US Right to Know petitioned the Federal Trade Commission and the Food and Drug Administration to investigate the marketing and advertising practices of "diet" products containing aspartame. However, the agencies declined to take action. More recently, in July 2023, the International Agency for Research on Cancer (IARC) classified aspartame as "possibly carcinogenic to humans." The World Health Organization advised against consuming non-sugar sweeteners, including aspartame, for weight loss, citing increased risks of type 2 diabetes, cardiovascular diseases, all-cause mortality, and weight gain based on a systematic review of scientific evidence.

Numerous studies have raised concerns about aspartame's safety, and questions have been raised about the industry-funded research and the approval process by the FDA. While some studies report no issues with aspartame, independent research conducted over decades links it to a range of health problems. These include cancer, brain tumors, cardiovascular disease, Alzheimer's disease, seizures, and neurotoxicity. Additionally, aspartame may lead to headaches, migraines, anxiety, mood disorders, and weight gain. The safety assessment conducted by the European Food Safety Authority (EFSA) has also faced criticism for downplaying potential harm. Industry-funded studies have influenced reassuring evidence, raising concerns about bias.

Furthermore, beverage companies like Coca-Cola have been implicated in employing aggressive PR tactics, including hiring scientists and physicians to defend sweeteners like aspartame in public forums. It is evident that more research and scrutiny are necessary to ensure the safety of aspartame-containing products and to protect vulnerable populations, such as pregnant women and children, from potential harm.