People who drink diet sodas daily have three times the risk of stroke and dementia compared to people who rarely drink them, researchers reported Thursday. It's yet another piece of evidence that diet drinks are not a healthy alternative to sugary drinks, and suggests that people need to limit both, doctors said. The researchers, led by Matthew Pase ... and colleagues, studied more than 4,000 people for their report, published in the journal Stroke. We found that those people who were consuming diet soda on a daily basis were three times as likely to develop both stroke and dementia within the next 10 years as compared to those who did not consume diet soda," Pase told NBC News. "Our study provides further evidence to link consumption of artificially sweetened beverages with the risk of stroke," the team wrote. "To our knowledge, our study is the first to report an association between daily intake of artificially sweetened soft drink and an increased risk of both all-cause dementia and dementia because of Alzheimer's disease." The team did not find the same risk for sugar-sweetened beverages. But they found other troubling signs. "Those who more frequently consume sugary beverages such as fruit juices and sodas had greater evidence of accelerated brain aging such as overall smaller brain volumes, they had poorer memory function and they also had smaller hippocampus, which is an area of the brain important for memory consolidation," Pase said.