Diet soda, once hailed as a healthy drink in the mainstream media, has been increasingly linked to serious health risks over the past few years.

Now, a new study is casting further doubt on the safety of artificially sweetened diet drinks, linking them to an increased risk of clot-based strokes, heart attacks and early death among women over 50 who drink more than two servings per day.

The study, conducted by the American Heart Association and American Stroke Association, tracked health outcomes for an average of 11.9 years in more than 80,000 post-menopausal women, who were asked how often they drank one 12-ounce serving of a diet beverage over the previous three months.

“Previous studies have focused on the bigger picture of cardiovascular disease,” said lead study author Yasmin Mossavar-Rahmani, an associate professor of clinical epidemiology and population health at the Albert Einstein College of Medicine in the Bronx, New York.

Mossavar-Rahmani and her team are not sure exactly what in diet drinks may be causing the issues, but it could relate to gut health or side effects of artificial sweeteners, including the controversial additive aspartame.

“Our study focused on the most common type of stroke, ischemic stroke and its subtypes, one of which was small-vessel blockage,” she said. “The other interesting thing about our study is that we looked at who is more vulnerable.”

Those found to have the highest risk were women with no history of heart disease or diabetes, and women who were obese or African American.

The study found that women who consumed two or more artificially sweetened drinks were 31 percent more likely to have a clot-based stroke, 29 percent more likely to have heart disease and 16 percent more likely to die from any cause than women who drank diet drinks less than once per week or not at all.

The researchers also found that those women who had no heart disease or diabetes but were heavy consumers of diet drinks were nearly 2 ½ times more likely to have a small-artery occlusion, a common type of stroke caused by blockage of the smallest arteries inside the brain.

Previous research has shown a link between the beverages and stroke, dementia, Type 2 diabetes, obesity and metabolic syndrome, which can lead to heart disease and diabetes.

While it was noted that the association may also be attributed to rising blood pressure or blood sugar increases not yet diagnosed as hypertension or diabetes, American Academy of Neurology President Dr. Ralph Sacco stressed that a pattern is developing in regards to the health risk of these drinks that should be taken seriously.

“The more you begin to question, the more you begin to feel strongly about the association being real,” he said.

For more information, read the full report from CNN Health here.