Artificial Sweetener Drinks Linked to Heart Flutters

Adults who regularly drink artificially sweetened drinks have a higher risk of irregular heart rhythms, according to a new study.

After trawling through health data from the UK Biobank, Shanghai Jiao Tong University researchers observed that participants who reported drinking two liters or more of artificially-sweetened drinks per week had a higher risk of atrial fibrillation and other irregular heart rhythms, compared with adults who drank fewer such beverages.

Adults who regularly drank pure, unsweetened fruit juices had a lower risk of atrial fibrillation.

The findings were published in Circulation: Arrhythmia and Electrophysiology.

Sweethearts

The researchers reviewed dietary questionnaire answers and genetic data taken from 201,856 adults (who hadn’t been diagnosed with atrial fibrillation when they enrolled in the UK Biobank between 2006 and 2010).

During the nearly 10-year follow-up period, 9,362 cases of atrial fibrillation were diagnosed among the cohort.

The team found that, compared to people who didn’t consume any sweetened drinks, there was a 20% increased risk of atrial fibrillation among those who drank more than 2 liters per week of artificially-sweetened beverages, and a 10% increased risk among participants who reported drinking 2 liters per week or more of sugar-sweetened beverages.

People who said they drank one liter or less of pure fruit juice each week, on the other hand, had an eight percent lower risk of atrial fibrillation.

Participants who consumed plenty of artificially sweetened beverages were more likely to be female, young, have a higher body mass index (BMI) and a higher prevalence of type 2 diabetes.

Participants who consumed sugar-sweetened beverages were more likely to be male, young, have a higher BMI, a higher prevalence of heart disease and lower socioeconomic status.

Those who drank sugar-sweetened beverages and pure juice were likelier to have a higher intake of total sugar than those who drank artificially sweetened drinks.

Smokers who drank more than 2 liters per week of sugar-sweetened beverages also had a 31% higher risk of atrial fibrillation; no significant increase in risk was noted for former smokers or those who had never smoked.

Although the findings don’t reveal a cause-and-effect relationship between sweeteners and such cardiac issues, the researchers insist their results are strong enough to discourage the regular use of sweetened drinks.

“Our study's findings cannot definitively conclude that one beverage poses more health risk than another due to the complexity of our diets and because some people may drink more than one type of beverage,” said lead study author Ningjian Wang, a researcher at the Shanghai Ninth People's Hospital and Shanghai Jiao Tong University School of Medicine in Shanghai, China.

“However, based on these findings, we recommend that people reduce or even avoid artificially sweetened and sugar-sweetened beverages whenever possible. Do not take it for granted that drinking low-sugar and low-calorie artificially-sweetened beverages is healthy, it may pose potential health risks.”

Other researchers have been less impressed by Wang's results. In a statement to the UK's Science Media Centre, Dr. Duane Mellor, a registered dietitian and senior lecturer at Aston University, said the following:

“This study claimed to find that individuals who drank more than 2L per week had an increased risk of atrial fibrillation (a variation in part of the heart beat linked to increased risk of other conditions like stroke). However, the data this was based upon was only 5 separate single day food intake recalls which were taken over the first three years of the study, so this data had to be extrapolated to estimate weekly intake. Although there is an increased risk, there is limited explanation of how sweeteners might increase risk of atrial fibrillation, so there is a limited biological reason to explain how sweetened drinks could be linked to heart health."

Not so sweet

While most health authorities consider artificial sweeteners, on the whole, safe to consume, other recent studies have highlighted the flavorings’ unsavory cardiac effects. 

One paper, published last year in Nature Medicine, observed that patients who had experienced heart attacks and strokes were more likely to have elevated levels of the sweetener erythritol in their blood. After experimenting with the flavoring in the lab, the researchers seemingly proved that the sweetener did make human platelets easier to activate and clot, fostering “enhanced thrombosis.”

When it comes to behavioral effects, several studies have also linked sweeteners to nervousness. One experimental study published last year found that aspartame produced anxiety-like behavior in mice.

“We believe that aspartame produces a shift in the excitation-inhibition balance, in favor of excitation,” Pradeep Bhide, chair of Developmental Neuroscience at Florida State University College of Medicine, told Technology Networks at the time.

Reference: Sun Y, Yu B, Yu Y, et al. Sweetened beverages, genetic susceptibility, and incident atrial fibrillation: a prospective cohort study. Circ Arrh And Electro. 2024. doi: 10.1161/CIRCEP.123.012145

This article is a rework of a press release issued by the American Heart Association. Material has been edited for length and content.

*This article was updated on May 5, 2024, to incorporate expert comments.