Consuming two liters of diet soda or other artificially sweetened drinks a day can increase the risk of a dangerous irregular heartbeat by 20% compared with people who drink none, according to a new study by researchers in China.

The study, from Shanghai, found that people who drink such beverages are more susceptible to a condition known as atrial fibrillation.

Theodore Maglione, an assistant professor of medicine and a cardiologist specializing in cardiovascular disease and cardiac arrhythmias at Robert Wood Johnson University hospital in New Jersey, told the Guardian: “Atrial fibrillation is a chaotic quivering of the top chambers of the heart. Normally, they beat in an organized fashion.”

Symptoms of atrial fibrillation, or “A-fib”, include “fatigue, shortness of breath, [and] palpitations”, Maglione said.

A-fib can often be genetic, Maglione said, but there are also some modifiable risk factors.

“Some things you cannot control are your genetics and age – which is a big risk factor as well. Some of the things you can control would include smoking, hypertension, uncontrolled sleep apnea, obesity and nutrition,” he said.

Making sure blood pressure is optimized is important when it comes to A-fib, as well as a “heart-healthy lifestyle”, Maglione said.

“Diet and exercise has been shown to decrease recurrence rates of atrial fibrillation after we treat them with certain procedures,” he said.

“The jury’s not out on whether the low-calorie or zero-calorie sodas with artificial sweeteners are any healthier than the conventional for-calorie sodas.”

Maglione said that when it comes to A-fib and nutrition, avoiding foods that are high in cholesterol and fat, and doing regular exercise, are key.

“Even modest weight loss has been associated with much lower recurrence rates of atrial fibrillation after treatment,” he said.

A-fib can also lead to blood clots, strokes and other heart-related complications.

The US’s Centers for Disease Control and Prevention says stroke is “a leading cause of serious long-term disability”. And atrial fibrillation is the leading cause of stroke in the United States.

Those above 65 are at greater risk for heart conditions such as A-fib and stroke, making it more important for this group to follow a healthy lifestyle and to avoid artificially sweetened drinks.

Maglione said there was also some evidence linking atrial fibrillation to early dementia later in life.

The study also looked at added-sugar beverages and pure unsweetened juices, such as orange juice. It was found that added-sugar beverages raised the risk of A-fib by 10%, while drinking roughly four ounces of pure unsweetened juices lowered the risk of the condition by 8%.

Penny Kris-Etherton, a nutritional sciences professor at Penn State University, told CNN: “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.”

Soda fiend or not, Maglione said it was important to be aware when it comes to medical matters of the heart.

“If you feel any symptoms of irregular heartbeat or palpitations, seek out medical care,” he said. “Because usually with earlier intervention, we can be more successful in treatment and preventing any of the things like stroke from occurring.”