Sugar sweetened beverages such as sodas have received a wide-scale bad reputation for their negative impact on health. All the while, diet sodas are falsely promoted as a healthier alternative. But artificial sweeteners such as aspartame, used in diet soda, have also been tied to numerous health complications, with one study linking artificial sweeteners to premature delivery.
Although some attest to the safety of artificial sweeteners like aspartame, these sweeteners have actually been shown to cause considerable harm.
http://www.activistpost.com/2012/05/artificial-sweeteners-linked-with.html