In studies done on mice, aspartame, sucralose, saccharin, and acesulfame potassium caused a higher incidence of cancer. Studies in humans are challenging because it can take decades for cancers to develop and be diagnosed. One 20-year human study found that men (but not women) who drank at least one diet soda a day had a slightly higher risk of multiple myeloma and non-Hodgkin lymphoma.
Conclusion—there is strong evidence that aspartame, sucralose, saccharin, and acesulfame potassium cause cancer in mice. Many scientists believe there is a good correlation between the cancer risk of these ingredients in mice and humans.