Low-carb diets could cause common heart disorder, study says

Many doctors have warned against low-carbohydrate diets, and now they believe they could cause a common heart disorder.

According to the American College of Cardiology, scientists from health institutions in China recently conducted a study to determine the relationship between carbohydrate intake and AFib, the most common heart rhythm disorder.

To do so, they examined the health records of nearly 14,000 people for more than two decades. The participants were asked to complete a questionnaire, where they reported their daily intake of 66 different food items. They then estimated the subjects' daily carbohydrate intake and the proportion of daily calories that came from carbohydrates.

"Researchers then divided participants into three groups representing low, moderate and high carbohydrate intake, reflecting diets in which carbohydrates comprised less than 44.8 percent of daily calories, 44.8 to 52.4 percent of calories, and more than 52.4 percent of calories, respectively," the team explained in a statement.

After analyzing the results, they found people in the low-carb group were more likely to develop AFib. In fact, they were 18 percent more likely to have the condition compared to the moderate-carb group and 16 percent more likely to have it compared to the high-carb group.

"The long-term effect of carbohydrate restriction is still controversial, especially with regard to its influence on cardiovascular disease," coauthor Xiaodong Zhuang said in a statement. "Considering the potential influence on arrhythmia, our study suggests this popular weight control method should be recommended cautiously."

The analysts also said low-carb diets were associated with increased risk of AFib regardless of the type of protein or fat eaten.

While the team didn't determine why restricting carbohydrates might lead to AFib, they believe people on such diets consume fewer vegetables, fruits and grains, which are foods know to reduce inflammation.

"Without these foods people may experience more inflammation, which has been linked with AFib," they wrote.

They also explained that eating more protein and fat to replace carbohydrate-rich foods can cause oxidative stress, which has also been associated with AFib.

Despite their findings, the team noted they cannot prove cause and effect. They said more investigations are need to confirm their results.