Low-carb diets tied to common heart rhythm disorder, research finds

By Anthony Magnano, M.D., Ascension St. Vincent’s Riverside

Low-carb diets are all the rage, but can cutting carbs spell trouble for your heart? A study presented at the American College of Cardiology’s Scientific Session revealed a link between low-carb diets, like the keto diet, and an increased risk for a serious heart rhythm disorder: atrial fibrillation, or AFib. It found that participants reporting low carbohydrate intake were 18 percent more likely to develop AFib than those with high carbohydrate intake. Now is always the perfect time to evaluate your diet and how what you eat affects your heart health.

Link between low-carb diets and heart health

This research has serious implications, because it shows a link between diet and AFib. While studies like this are certainly concerning, it’s important to note that they are only observational and do not directly prove causation. After looking a little deeper, this study classified “low-carb” diets as those in which carbohydrates comprised less than 44.8 percent of daily calories. That’s almost half of a person’s daily calories coming from carbs. To put that in perspective, with the keto diet, only about 5-to-10% of calories come from carbohydrates. The study didn’t necessarily show the effects of low-carb diets as we think of them. But, it brings our attention to the importance of choosing heart-healthy diets to prevent the risk of AFib.

How atrial fibrillation affects the heart

AFib affects millions of Americans, but many don’t experience symptoms and the condition goes undiagnosed. With AFib, the heart doesn’t always beat or keep pace the way it should. There is a rapid and chaotic heartbeat that can result in reduced heart function. Even though many people don’t notice this happening, it increases the chances of dangerous blood clots forming and causing a stroke. In fact, those with AFib are five times more likely to have a stroke. AFib can also lead to heart failure, and if untreated, doubles the risk of heart-related deaths.

Those patients who do notice symptoms of AFib can experience heart palpitations, shortness of breath, weakness or fatigue. AFib may occur in brief episodes, or it may be a persistent condition. There are many risk factors that contribute to AFib, including age, family history, underlying heart disease and other chronic conditions like diabetes. Some of the major risk factors like high blood pressure and obesity can be reduced through a healthy diet.

Heart-healthy diet options

Our goal is to prevent AFib, and one way to help is by maintaining a healthy weight. That’s why low-carb diets can be beneficial. Evidence shows that they promote healthy weight loss, which reduces the risk of coronary heart disease. However, given this research, low-carb diets may have unforeseen issues.

When it comes to a heart-healthy diet, the important thing is to maintain balance. A Mediterranean-style diet high in vegetables, fruits, lean proteins and whole grains has been shown to promote weight loss and reduce the risk of heart disease. Salmon, chicken, asparagus, spinach, brown rice and almonds are all great examples of heart-healthy foods. They help lower cholesterol and keep your blood pressure in check. At the same time, you want to limit high-sodium foods, such as canned or processed foods. Also limit high-fat foods, such as red meat, cheese and baked goods.

Talk with your doctor about your heart health

At least 80 percent of cardiac events are preventable, so it’s important to talk to your doctor about your diet and how it may affect your heart health. Everyone is different—just because a diet worked for one person doesn’t mean it will work for you. For example, some people have had success losing weight with high-protein diets, but a recent study from Washington University School of Medicine suggests that they may increase risk of heart attack. On the other hand, eating a high-quality, plant-based diet may reduce risk. Work with your doctor to establish a heart-healthy diet that is tailored to your lifestyle.

Dr. Anthony Magnano is a Ponte Vedra resident and cardiologist at Ascension St. Vincent’s Riverside. For more information on Dr. Magnano and his specialty treating Atrial fibrillation, visit Healthcare.ascension.org.