The data is now being called weak, but a study that linked some of the chemicals in artificial sweeteners to blood cancers like leukemia may have some merit. 

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Dr. Hamid Sayar, hematologist at the IU Health Simon Cancer Center, says he's cautious about any beverage that contains chemicals, including regular soda.  Sayar says the healthiest drink is still water. 

Despite numerous links in animal testing, no strong connections between blood cancers and diet soda have been found in humans.  Sayar says he hasn't seen any alarming evidence in his patients that there is a link between diet soda and cancer, but he says it's not typical to go through someone's nutritional history in such great detail.