Diet soda consumption has been linked to an increased risk of stroke or heart attacks.
Researchers say the risks for stroke and heart attack is higher in those who drink it every day versus those who have none. A simple solution, health experts say, is to drink water instead.
But why is diet soda risky? Doctors have no medical explanation. Some say those who drink lots of the beverage also fail to exercise, weigh more, drink more alcohol or have other risk factors like high blood pressure and smoking.
It's reasonable to have doubts, because we don't have a clear mechanism. This needs to be viewed as a preliminary study," said lead researcher Hannah Gardener of the University of Miami.
But for those trying to cut calories, "diet soft drinks may not be an optimal substitute for sugar-sweetened beverages," she said.
Dr Maureen Storey, senior vice-president of science policy for the American Beverage Association, said in a statement that there is no evidence "that diet soda uniquely causes increased risk of vascular events or stroke".
The study tracked more than 100 diet soda drinkers for a decade. It also took into account rates of smoking, diabetes, waistline size and other differences among the groups.
"The body of scientific evidence does show that diet soft drinks can be a useful weight management tool, a position supported by the American Dietetic Association. Thus, to suggest that they are harmful with no credible evidence does a disservice to those trying to lose weight or maintain a healthy weight."
