Study details and key findings

In the study, researchers analyzed data from 201,856 adults who were part of the U.K. Biobank database. Of the participants, 45.1% were men, and the average age was 56 years. Participants did not have AFib at baseline and were followed for a median of 9.9 years.

Diet information was taken from questionnaires about the participants' various eating habits, including how many cups of beverages they drank the previous day. Researchers then used this information to estimate participants' weekly consumption.

Although most participants did not report drinking any sugar-sweetened or artificially sweetened beverages, 6.6% drank over two liters or 8.5 cups of sugar-sweetened beverages a week, and 5.5% drank the same amount of artificially sweetened beverages.

People who drank higher amounts of artificially sweetened beverages were more likely to be female, younger, weigh more, and have a higher prevalence of Type 2 diabetes. Similarly, those who drank higher amounts of sugar-sweetened beverages were more likely to be male, younger, weigh more, and have a higher prevalence of heart disease.

Overall, the researchers found that people who drank more than two liters of sugar- or artificially sweetened beverages a week had an increased risk of AFib. Participants who drank sugar-sweetened beverages had a 10% increased risk, while those who drank artificially sweetened drinks had a 20% increased risk.

Smoking may have also impacted participants' risk of AFib. Smokers who drank more than two liters of sugar-sweetened beverages a week had a 31% higher risk of AFib. In comparison, former smokers and people who had never smoked had no significant increases in their risk.

Drinking less than two liters of sweetened beverages a week was not associated with an increased risk of AFib. Additionally, drinking one liter or less of pure fruit juice a week may be mildly protective against AFib, with these participants having an 8% decreased risk.

The researchers acknowledged that there could be unmeasured confounding in the study due to its observational nature. They also noted that participants could have misreported their dietary habits and that the findings from relatively healthy participants in Britain may not be applicable to other groups.

Commentary

"This is the first study to report an association between no- and low-calorie sweeteners and also sugar-sweetened beverages and increased risk of atrial fibrillation," said Penny Kris-Etherton, an emeritus professor of nutritional sciences at Penn State University and a member of the American Heart Association's nutrition committee. "While there is robust evidence about the adverse effects of sugar-sweetened beverages and cardiovascular disease risk, there is less evidence about adverse health consequences of artificial sweeteners.

Similarly, Robert Koeth and two colleagues from Cleveland Clinic, wrote that the study's findings "raise the possibility that artificial sweeteners may have a more important role and contribute to the pathogenesis of [AFib]."

"Among [artificially sweetened beverages] what artificial sweetener(s) are associated with [AFib]? What underlies the pathogenesis of this observation?" they wrote. "Are there indirect or direct effects of artificial sweeteners on the myocardium? Finally, should longer term studies be required before the introduction of artificial nutrients into the food?"

Both Kris-Etherton and Koeth and colleagues have called for more research to confirm the study's findings and better understand the potential impact on heart diseases and other conditions.

"In the meantime, water is the best choice, and, based on this study, no- and low-calorie sweetened beverages should be limited or avoided," Kris-Etherton said.

Ningjian Wang, a professor at the Shanghai Ninth People's Hospital and Shanghai Jiao Tong University School of Medicine and one of the study's authors, agreed, saying that people should "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," Wang added.

Separately, Theodore Maglione, an assistant professor of medicine and cardiologist at Robert Wood Johnson University Hospital, said that, regardless of a person's dietary habits, it's important to be aware of any potential heart issues.

"If you feel any symptoms of irregular heartbeat or palpitations, seek out medical care," Maglione said. "Because usually with earlier intervention, we can be more successful in treatment and preventing any of the things like stroke from occurring." (Salam, The Guardian, 3/5; LaMotte, CNN, 3/5; Lou, MedPage Today, 3/5; American Heart Association news release, 3/5)

The  American Heart Association (AHA)  rated  10 types of popular diets based on how well they align with AHA's dietary guidance, with the Dietary Approaches to Stop Hypertension (DASH) diet receiving a perfect score.