A major new study by the American Heart Association has just discovered something very alarming about diet sodas, a finding that could make people think twice about the zero-calorie beverages. The study found that artificially sweetened beverages may be associated with health risks not only to your body, but also your brain.

Diet sodas were tied to a higher risk of stroke in dementia in the new study, published in the AHA’s journal Stroke this past week. However, much research remains to be done, as scientists don’t know what the cause and effect relationship is, if there is one, between artificially sweetened drinks and an increased risk of stroke and dementia. The study only shows an association between the two, and therefore people shouldn’t jump to conclusions.

Interestingly, scientists did not find this connection with other sugary beverages like regular soda and fruit drinks, even though they are often fingered as a major culprit in the rising levels of obesity in America. This new finding suggests that there is a lot we don’t know about the diet drinks that are often used in place of regular sodas.

“Our study shows a need to put more research into this area given how often people drink artificially-sweetened beverages,” said Matthew Pase, Ph.D., a senior fellow in the department of neurology at Boston University School of Medicine, Swinburne University of Technology in Melbourne, Australia, and the Framingham Heart Study.

“Although we did not find an association between stroke or dementia and the consumption of sugary drinks, this certainly does not mean they are a healthy option. We recommend that people drink water on a regular basis instead of sugary or artificially sweetened beverages.”