Heart Attack and Stroke: Drinking diet sodas daily may increase the risks for heart attack and stroke and other vascular events by 43 percent, but no such threat exists with regular soft drinks or with less frequent consumption of diet soda. These results come from a study including more than 2,500 adults published online in the Journal of General Internal Medicine on January 30, 2012. So far, no one knows what it is about diet sodas that could explain the added risk.
Kidney Trouble: In 2009, researchers at Harvard found that drinking two or more diet sodas daily could lead to a 30 percent drop in a measure of kidney function in women. No accelerated decline was seen in women who drank less than two diet sodas daily. The drop held true even after the researchers accounted for age, high blood pressure, diabetes and physical activity.