A new study linked diet drinks to increased cardiovascular risks in post-menopausal women.

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The study looked at postmenopausal women and their cardiovascular risk. Getty Images

Switching to low-calorie and low-sugar sodas may seem like a healthy choice, but a new study finds that may not be the case.

According to a study in Strokepublished this month, postmenopausal women who consumed multiple diet drinks each day were more likely to have a stroke or other cardiovascular event.

The study comes as Americans are increasingly turning away from soda altogether. In recent years the popular beverage has been linked to a higher risk of obesity, even in diet form.

Researchers found that compared to women who had diet drinks less than once a week or not at all, women who had two or more diet drinks per day were significantly more at risk for vascular issues.

They were 23 percent more likely to have a stroke, 31 percent more likely to have a clot-caused stroke, 29 percent more likely to develop heart disease, and 16 percent more likely to die overall.

The self-reported data came from more than 81,000 women who were between 50 and 79 years old at the start of the study, which went from 1993 to 1998.

The authors caution that the results don’t prove that the diet drinks definitively cause stroke. Instead the study found there was a correlation between drinking more diet soft drinks and cardiovascular events.

Certain women are more at risk than others, the study noted. Those who had diet drinks more than twice daily had a doubled risk for stroke, especially if they previously had heart disease or diabetes.

Similarly, women who were obese without previous heart disease or diabetes were also at risk. African-American women without previous heart disease or diabetes were 3.93 times as likely to have a clot-caused stroke.

Along with other observational research, the current study shows that artificially sweetened drinks may not be harmless and that high consumption is associated with having a higher risk of both stroke and heart disease.

The results were obtained after adjusting for stroke risk factors, such as age, high blood pressure, and smoking.

In an accompanying editorial, researchers said the most interesting results was the fact that heavy diet drink consumption was associated with an increased stroke risk only in women who were obese — not those who were overweight or had a healthy body mass index.

Dr. Michael Miller, professor of cardiovascular medicine at the University of Maryland School of Medicine in Baltimore, has concerns with how the study was done and said more research is needed.

He said the better way to get more definitive results is to have a group of women matched for risk factors such as weight and cholesterol, and then to randomize them to groups consuming varying amounts of diet drinks daily and measure the response.

“In my opinion, this diet soda study falls flat,” he said.

Sylvia Wassertheil-Smoller, PhD, a co-author of the study from the Albert Einstein College of Medicine, told Healthline that the team would like to do more research on types of sweeteners and genetic factors that could predispose some people to respond negatively to artificial sweeteners. They’d also like to understand why the effect is so strong in African-American women.

The data didn’t include details on which sweeteners the women consumed, so it’s unclear which could be more harmful or specifically contribute to a higher stroke risk.

According to a science advisory published by the American Heart Association, there’s not enough scientific research to say if low-calorie sweetened drinks do or don’t change the risk factors for stroke and heart disease.

Rachel K. Johnson, PhD, RD, professor emeritus at the University of Vermont and the advisory’s writing group chair, said limiting diet drinks is the “most prudent” thing to do for your health.

Some experts have found that there’s not enough evidence to confirm that artificial sweeteners are harmful when consumed in small amounts, Miller notes. He recommends people consume no more than one 12-ounce diet soda or one packet of artificial sweetener per day.

Dr. Regina Druz, a cardiologist from New York, said she never recommends diet drinks or artificial sweeteners, “as they are known to result in obesity and diabetes and have no role in weight management.”

“Many well-meaning people, especially those who are overweight or obese, drink low-calorie sweetened drinks to cut calories in their diet,” Yasmin Mossavar-Rahmani, PhD, lead author of the study and associate professor at the Albert Einstein College of Medicine in the Bronx, New York, said in a statement.

Dr. Elizabeth Klodas, a Minneapolis-based cardiologist and founder of Step One Foods, said to stick to water.

“In general, my suggestion is to avoid all artificial and low-calorie sweeteners,” she told Healthline. “We simply do not have enough data to know what long-term exposure to these additives is.”

Klodas said that in one published study, artificial sweeteners were found to alter the function of the gut microbiome in mice, which then affected blood sugar metabolism.

Susan Swithers, PhD, a body weight researcher from Purdue University, said people generally seem to realize that daily soft drink intake isn’t healthy.

“The public shouldn’t be assuming that shifting from regular to diet soft drinks will automatically improve health, or that drinking diet soft drinks regularly is healthy,” she added.

People should also work to prevent and treat known stroke factors, such as diabetes, smoking, high blood pressure, high cholesterol, atrial fibrillation, and physical inactivity, according to Dr. Laura Stein, assistant professor of neurology at the Icahn School of Medicine at Mount Sinai in New York.

“While water is the best alternative to sugary beverages, those who substitute artificially sweetened beverages for sugary beverages should be reminded of the importance of all things in moderation and encouraged to work toward minimizing long-term consumption,” she noted.