That said, almost two-thirds of the women consumed diet sodas or drinks very infrequently, meaning less than once a week or never.
The new findings are based on a big study of women and show some groups are at even greater risk, with those drinking two or more diet drinks a day who were also obese having more than double the stroke risk.
Dr Yasmin Mossavar-Rahmani, lead author of the study and associate professor of clinical epidemiology and population health at the Albert Einstein College of Medicine in the Bronx, New York, said:'Many well-meaning people, especially those who are overweight or obese, drink low-calorie sweetened drinks to cut calories in their diet.
The study focused on over 80,000 post-menopausal women in the United States for an average of 11.9 years.
At the end of three years, the women were asked to report on their consumption of diet drinks, low calorie, artificially sweetened colas, fruit drinks, sodas etc. over the previous three months.
Research shows that consuming just two diet drinks or artificially sweetened drinks per day can raise the risk of stroke by a quarter (23 percent) and risk of heart disease by a third (29 percent).
One serving of a diet drink in the study was regarded as 355ml.
Investigators tracked the general health of all the enrollees for an average of almost 12 years.
After taking into consideration a variety of stroke risk factors - including blood pressure status, smoking history and age - the study team concluded that heavy consumption of diet drinks did appear to be tied to cardiovascular risks in a number of ways.
As for the type of artificial sweetener, did the researchers find one in particular to be the culprit? No. Beware, your heart could be at risk. These results in postmenopausal women may not be generalizable to men or younger women.
"What is it about these diet drinks?"
"It is likely study subjects were already at a greater health risk and chose low-calorie sweetened beverages to manage their calorie and sugar intake as these products are proven safe and beneficial for those managing their weight and blood glucose levels", said Robert Rankin, president of the Calorie Control Council.
She says that more studies need to be done to tease apart which artificial sweeteners might be more or less associated with stroke, and to track more closely how long people drink diet beverages before their risk starts to rise.