Observational Study Linking No- and Low-Calorie Sweetened Beverages with Stroke and Dementia Not Based on Cause and Effect, Does Not Represent Risk to Americans

April 20, 2017 — While a recent study alleges consumption of diet beverages sweetened with no- and low-calorie sweeteners increases risk for stroke and dementia, the study suffers from limitations which impact the generalizability of the authors’ conclusions.

In the paper, “Sugar- and artificially-sweetened beverages and the risks of incident stroke and dementia: A prospective cohort study,” published in Stroke, Pase et al. report that “artificially-sweetened soft drink consumption was associated with an increased risk of stroke and dementia…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.”

The findings are based on data collected during 1991-2001 as part of the Framingham Heart Study Offspring Cohort study, which examined various health outcomes including incidence of stroke and dementia during a 10 year follow-up period. The current study suffers from several major limitations, including:

1. The study is observational, and while it can suggest a potential association, the study cannot be used to assess causation; therefore, these results should not cause alarm. It is well known that people with certain health conditions, such as obesity and diabetes, are at higher risk for stroke and dementia. Many individuals trying to manage their obesity and diabetes often include foods and beverages containing no- and low-calorie sweeteners in their diets as a way to manage their condition. However, this does not mean that consuming such beverages causes obesity, diabetes, or any other health conditions. In fact, studies have shown that no- and low-calorie sweetened beverages help reduce energy intake and body weight.¹
2. When researchers conducted statistical analysis to determine risk, confounding variables were not wholly considered. A more thorough examination would have included all well-established risk factors for stroke and dementia such as socioeconomic status, body mass index, drug use, alcohol intake, family history, and depression. In fact, the authors cautioned readers about possible reverse causality that cannot be excluded in this study.
3. The study population lacked ethnic diversity and does not represent the American population, so it is difficult to generalize results to all American adults.

“This study design has significant limitations and is unable to prove a causal relationship between artificial sweeteners and stroke or dementia. Known risk factors for stroke and dementia such as high cholesterol, diabetes and high blood pressure can be prevented by maintaining a healthy weight. Swapping out sugary drinks and foods for those containing no- and low-calorie sweeteners remains a valuable tool for people looking to cut calories in order to reach their weight loss goals.” Keri Peterson, MD

All no- and low-calorie sweeteners used in diet beverages have routinely been reviewed and deemed safe by numerous regulatory agencies, including the US Food and Drug Administration. Furthermore, healthcare experts, including the American Diabetes Association, the American Heart Association, and the Academy of Nutrition and Dietetics, acknowledge the role that no- and low-calorie sweeteners can have in managing health concerns, such as diabetes and obesity. The American Heart Association states, “Replacing sugary foods and drinks with sugar-free options containing NNSs [no- and low-calorie sweeteners] is one way to limit calories and achieve or maintain a healthy weight. Also, when used to replace food and drinks with added sugars, it can help people with diabetes manage blood glucose levels.²”

“Individuals can choose to modify their lifestyle to reduce their risk of stroke by participating in more physical activity, achieving and maintaining a healthy body weight, and smoking cessation. Beverages are an important consideration and diet beverages provide safe, reduced calorie options that people can enjoy while working towards achieving their healthy lifestyle goals,” says Robert Rankin, President of the Calorie Control Council, “Rather than focusing on results from observational studies, which cannot establish cause and effect, individuals should talk to their healthcare team to address known risks for stroke and dementia.”

Keri Peterson, MD and medical advisor to the Calorie Control Council added, “This study design has significant limitations and is unable to prove a causal relationship between artificial sweeteners and stroke or dementia.  Known risk factors for stroke and dementia such as high cholesterol, diabetes and high blood pressure can be prevented by maintaining a healthy weight.  Swapping out sugary drinks and foods for those containing no- and low-calorie sweeteners remains a valuable tool for people looking to cut calories in order to reach their weight loss goals.”