Which artificial sweetener or sugar substitute is not connected to cancer?

Stevia: In my opinion, stevia is the safest artificial sweetener currently available. If you are a diabetic, you might consider tupelo honey - a variety of honey that reportedly does not spike blood sugar.

None of them are!: Study the evidence. The trials in the 1970s triggering cancer in rats with cyclamate + saccharin used gigantic doses & have no clear relevance to either usual dosages or humans. Study: http://www.cancer.gov/cancertopics/factsheet/Risk/artificial-sweeteners. However, there is evidence that real sugar is linked to a higher incidence of cancer, both directly and through promoting obesity.