Last month the American College of Cardiology published a study that tied eating a diet low in carbohydrates with a heart problem called atrial fibrillation, or AFib.
Low-carb diets such as the Keto diet or the Paleo, Atkins or South Beach diets before are known for fast weight loss as people decrease the carbs — and often increase the fats.
This study looked at 14,000 people from 1995 to 2016. The participants were asked to report their daily intake of food on a questionnaire and the researchers then estimated what proportion of their daily calories were made up of carbs.
Of those who did not have AFib when they enrolled, 1,900 people later were diagnosed with it. The researchers then divided participants into people who fit in what is considered the healthy range of 44.8 percent to 52.4 percent daily intake of carbs and people who were above that or below that.
The participants who were below the healthy range for carbs were 18 percent more likely to develop AFib than those with moderate carb intake and 16 percent more likely to develop AFib than those with high carb intake.
Why do we care about AFib?
AFib is an an abnormal heart rhythm that happens when the upper chamber of the heart no longer beats in a regular way, says Dr. Amin Al-Ahmad, a cardiac electrophysiologist at the Texas Cardiac Arrhythmia Institute at St. David’s Medical Center in Austin, Texas. Normally, the upper chamber beats and then the lower chamber beats. In AFib, the upper chamber no longer is organized electrically and it bombards the lower chamber with signals that results in the lower chamber beating irregularly and rapidly, Al-Ahmad explains.
It’s important because AFib can cause a fast heart rate, irregular heart rate and symptoms like shortness of breath, palpitations and tiredness. It puts people at risk for a blood clot in the upper chamber and stroke.
The causes are unclear, but it’s associated with increase of age, high blood pressure and other types of heart problems, he says.
Sometimes people don’t feel it or sometimes it sneaks up on them and they don’t notice that they are increasingly tired, he says.
To treat AFib, you might use a blood thinner to reduce stroke risk or medicine to slow down the heart rate. Doctors also might do an ablation to put catheters in the heart to cauterize the areas causing the AFib.
“It’s very treatable,” Al-Ahmad says.
“It’s not something you want to ignore for a long time,” he adds. See your doctor within a day or two, but if you are feeling poorly, seek attention right away.
The researchers in this study were very careful to say that they did not find a direct cause between low-carb diets and AFib, but instead found an association.
The problem with a study like this one, Al-Ahmad says, is that it relies on participants to remember what they ate and accurately record it.
It also assumes that what you are eating is the reason, when there might be other factors. “People who may be on that specific diet may also have a weight problem specifically associated with AFib,” he says.
“I would consider it to be interesting and perhaps useful to generate a hypothesis but not necessarily in any way indicting to that type of diet causative or even associated with AFib,” he says.
Al-Ahmad recommends thinking about reduction rather than elimination of bad actors such as sugar. Keto, though, is effective in losing weight and that weight loss might outweigh the harm you get from eliminating a food. If you can achieve weight loss with a more moderate approach, it will be better, he says.
“Anything on the extreme level is concerning,” he says. “Trying to achieve balance is more important.”