An analysis of health data found a 20% higher risk of atrial fibrillation among people who said they drank two liters or more per week (about 67 ounces) of artificially sweetened drinks.
The risk was 10% higher among people who said they drank similar amounts of sugar-sweetened beverages.
Consuming sweetened drinks has been linked to type 2 diabetes and obesity in previous research: but the new study is among the first to assess a possible link between sugar- or artificially sweetened beverages and atrial fibrillation.
The study also found that drinking one liter (about 34 ounces) or less per week of pure, unsweetened juice, such as orange or vegetable juice, was associated with a lower risk of atrial fibrillation (AFib).
10 year follow up
Researchers drew on health data from the UK Biobank: a large, biomedical database with health records from the National Health Service.
They assessed dietary questionnaires and genetic data for 201,856 adults, aged 37 – 73, who were free of AFib at the time they enrolled in the UK Biobank between 2006 and 2010. Forty five percent of the participants were male.
During the nearly 10-year follow-up period, there were 9,362 cases of AFib among the study participants.
Compared to people who did not consume any sweetened drinks, there was a 20% increased risk of atrial fibrillation among people who said they drank more than 2 liters per week (about 67 ounces or more, or roughly one 12-ounce drink six days a 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 1 liter (about 34 ounces) or less of pure fruit juice each week had an 8% lower risk of atrial fibrillation.
Smoking may have affected risk: with smokers who drank more than two liters per week of sugar-sweetened beverages having a 31% higher risk of AFib.
There was no data on caffeine intake from the drinks.
The results are published in Circulation: Arrhythmia and Electrophysiology: a peer-reviewed journal of the American Heart Association.
Atrial fibrillation is a condition in which the heart beats irregularly, increasing the risk of stroke by five-fold. More than 12 million people are expected to have AFib by 2030, according to the American Heart Association’s 2024 Heart Disease and Stroke Statistics.
The risk factors for AFib increase with age, notes the CDC, with other factors including high blood pressure, obesity, European ancestry, diabetes, chronic kidney disease, moderate to heavy alcohol intake and smoking.
The complexity of modern diets means the study cannot definitively conclude one beverage poses more risk than another. Meanwhile, the findings were observational and cannot prove causation between consumption of certain types of beverages and AFib risk.
Researchers also evaluated whether a genetic susceptibility to AFib was a factor in the association with sweetened beverages. The analysis found the AFib risk was high with the consumption of more than 2 liters of artificially sweetened drinks per week regardless of genetic susceptibility.
“Although the mechanisms linking sweetened beverages and atrial fibrillation risk are still unclear, there are several possible explanations, including insulin resistance and the body’s response to different sweeteners,” said lead study author Ningjian Wang, M.D., Ph.D., a researcher at the Shanghai Ninth People's Hospital and Shanghai Jiao Tong University School of Medicine in Shanghai, China.
“Artificial sweeteners in food and beverages mainly include sucralose, aspartame, saccharin and acesulfame.”
Artificial sweeteners
Artificial sweeteners have played a large role in sugar reduction in beverages. But the latest research on atrial fibrillation is another blow to the category: following on from WHO guidance, published last year, that recommended against the use of non-sugar sweeteners to control body weight or reduce the risk of non-communicable diseases.
But the International Sweeteners Association, a trade group representing the industry, highlights that the atrial fibrillation study cannot prove cause and effect.
"Robust evidence from randomised controlled trials and prospective cohort studies with rigorous analytical methods reaffirm that low/no calorie sweeteners have no adverse effect on heart health and may even offer some benefits for cardiometabolic health," it says. "The recent observational study [on atrial fibrillation] may risk confusing consumers given observational research cannot establish a cause-and-effect relationship."
Nor does the study provide any mechanistic evidence about how low/no calorie sweetened beverage consumption could be a cause of atrial fibrillation, continues the association.
"Actually, risk factors of atrial fibrillation include obesity and type 2 diabetes, among others, and we know that people living with such conditions may use low/no calorie sweeteners as a risk reduction strategy in their effort to limit their sugars intake.
"In fact, participants with a higher body mass index and a higher prevalence of type 2 diabetes consumed more low/no calorie sweetened beverages in this study. In addition, the impact of residual confounding cannot be ruled out, as the study could not consider all potential confounders and known causes of atrial fibrillation. The results of this study could be a typical case of reverse causation which frequently affects observational research studying the health effects of low/no calorie sweeteners."
American Heart Association guidance
American Heart Association already advises limited intake of sugar-sweetened beverages. But a 2018 science advisory from the American Heart Association noted the lack of large, long-term, randomized trials on artificial sweeteners.
Kris-Etherton, an emeritus professor of nutritional sciences at Penn State University and American Heart Association nutrition committee member (but not involved with the Circulation study), was a co-author of the association’s science advisory on artificial sweeteners.
“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,” she said. “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.
“We still need more research on these beverages to confirm these findings and to fully understand all the health consequences on heart disease and other health 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.”