Artificial sweeteners may increase the risk of stroke, dementia

After adjusting for age, sex, physical activity and other variables, adults who drank artificially sweetened soft drinks had an increased risk of ischemic stroke, all-cause dementia and Alzheimer’s disease, according to an observational study.

The researchers also found that sugar-sweetened soft drinks were not associated with an increased risk of stroke or dementia.

Lead researcher Matthew Pase, PhD, of the Boston University School of Medicine, and colleagues published their results online in Stroke on April 20.

Examples of artificially sweetened beverages include diet soda and other diet drinks.

“Our study shows a need to put more research into this area given how often people drink artificially-sweetened beverages,” Pase said in a news release. “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.”

The researchers evaluated participants from the Framingham Heart Study Offspring cohort, which began in 1971. Since then, participants have been monitored nine times, most recently in 2014. However, the researchers estimated the 10-year risks of incident stroke and dementia beginning from the seventh examination cycle, which was from 1998 to 2001.

For the stroke analysis, the researchers excluded participants with prevalent stroke or other significant neurological disease at baseline and those who were younger than 45 years old. For the dementia analysis, they excluded participants who had prevalent dementia, mild cognitive impairment or other significant neurological disease at baseline and those who were younger than 60 years old.

The stroke analysis included 2,888 adults and the dementia analysis included 1,484 participants. All of the participants completed the Harvard semiquantitative food-frequency questionnaire, which measured dietary intake over the past 12 months.

The researchers found that the prevalence of cardiovascular disease and diabetes decreased with more frequent consumption of total sugary beverages, although they increased with greater consumption of artificially sweetened soft drinks.

They also noted that greater recent consumption of artificially sweetened soft drinks was associated with an increased risk of stroke, particularly for ischemic stroke. However, intake of total sugary beverages and sugar-sweetened soft drinks were not associated with increased risks of stroke.

In addition, they noted that daily intake of artificially sweetened soft drinks was associated with an increased risk of all-cause dementia and Alzheimer’s disease, although the associations were not significant when they adjusted for several variables. Further, they mentioned that total sugary beverages and sugar-sweetened soft drinks were not associated with an increased risk of dementia or Alzheimer’s disease.

The researchers acknowledged a few limitations of the study, including that they did not include ethnic minorities, which limits the generalizability of the findings. They also mentioned that the observational design of the study precluded them from making causal links between artificially sweetened beverage consumption and the risks of stroke and dementia. In addition, using a self-report questionnaire could result in subject recall bias. Further, they noted that residual confounding could effect the results.

“As the consumption of artificially sweetened soft drinks is increasing in the community, along with the prevalence of stroke and dementia, future research is needed to replicate our findings and to investigate the mechanisms underlying the reported associations,” they wrote.