Diet drinks, once thought as a good alternative to sugary drinks to reduce diabetes and obesity, may actually put you at a greater risk of stroke and dementia, new research has found.
Just one artificially sweetened beverage a day appears to increase the odds by a factor of three, compared with drinking less than once a week, according to the research published this week in the American Heart Association's journal Stroke.
The researchers cautioned that the study only observed the tread mainly among one group of people and cannot establish a cause-and-effect relationship.
"Our study shows a need to put more research into this area given how often people drink artificially-sweetened beverages," said Matthew Pase, a senior fellow in the department of neurology at Boston University, Swinburne University of Technology in Melbourne, Australia, and the Framingham Heart Study, a U.S. health project that kicked off in 1948 to identify factors contributing to cardiovascular disease.
The researchers analyzed the Framingham Heart Study Offspring Cohort of 2,888 people, primarily Caucasian, over the age of 45 for the stroke study and 1,484 people over the age of 60 for the dementia arm of the study.
Over a period of seven years, the researchers reviewed what people were drinking at three different points in time.
Then, they followed up with the study subjects for the next 10 years to determine who developed stroke or dementia, and compared the dietary information to the risk of developing stroke and dementia over the course of the study.
At the end of the 10-year follow-up period, 97 people, or three percent, suffered from stroke, 82 of which were ischemic, or caused by blockage of blood vessels; while 81 people, or five percent, developed dementia, 63 of which were diagnosed as Alzheimer's disease.
After adjusting for various risk factors such as age, sex, caloric intake and education, they found that people who drank at least one artificially-sweetened beverage a day were three times as likely to develop ischemic stroke and 2.9 times as likely to develop Alzheimer's disease dementia.
Interestingly, the researchers did not see an association with regular soda, probably because people did not drink sugary sodas as often as diet sodas, Pase said.
"This certainly does not mean they are a healthy option," he said. "We recommend that people drink water on a regular basis instead of sugary or artificially sweetened beverages."
Meanwhile, Pase noted only a small number of people in the study developed either dementia or stroke, so "it is by no means a certain fate."
In an accompanying editorial, Ralph Sacco, a former president of the American Heart Association, said that the current body of scientific research is inconclusive regarding whether or not drinking artificially sweetened beverages can actually lead to stroke, dementia or other cardiovascular conditions.
"The growing number of epidemiological studies showing strong associations between frequent consumption of [artificially sweetened beverages] and vascular outcomes, however, suggests that it may not be reasonable to substitute or promote [artificially sweetened beverages] as healthier alternatives to [sugarsweetened beverages]," said Sacco, now the chairman of the Department of Neurology at the University of Miami. "Both sugar and artificially sweetened soft drinks may be hard on the brain."
