The findings come from a federally funded study of about 2,500 adults in the New York City area.
Doctors have no explanation for why diet soda might be risky. It could be that people who drink lots of it also fail to exercise, weigh more or have other risk factors like high blood pressure and smoking. However, the researchers took these factors into account and found the trend remained.
What to do? Drink water, the experts suggest.
The study was discussed Wednesday at an American Stroke Association conference in Los Angeles.