Can the Keto Diet Trigger Atrial Fibrillation? Exploring the Science Behind This Diet-Heart Connection

The ketogenic diet is often talked about as a promising diet to improve one’s health outcomes. The diet is known for promising weight loss, improved energy, and metabolic benefits. But for individuals with atrial fibrillation (Afib), this high-fat, low-carb lifestyle may come with hidden risks. From electrolyte imbalances to the effects of rapid weight loss, the keto diet could inadvertently trigger episodes of irregular heartbeat. By understanding these potential pitfalls, you can choose a diet that suits your goals and works best with your overall health.

Key points:

What is the keto diet?

The ketogenic (keto) diet is characterized by extreme carbohydrate intake reduction.

Nutritional ketosis, the desired goal of ketogenic diets, is attained by limiting carbohydrate intake, regulating protein consumption, and increasing the proportion of calories derived from fat.

This diet has gained popularity for its rapid weight loss effects. While it can lead to rapid short-term reductions in body weight, triglycerides, and blood pressure, evidence for its long-term efficacy is limited.

Potential benefits of the ketogenic diet

Though the diet is still heavily debated as a treatment for individuals with cardiovascular disorders, research has indicated that there are also possible positive effects of the keto diet. Benefits include reduced triglycerides, and increased HDL (“good cholesterol”). The diet has also been seen to potentially lower blood pressure, improve insulin resistance, and reduce small dense LDL particles linked to higher cardiovascular risk. These effects have been observed across various populations but long term outcomes still remain unclear.

Potential risks of the keto diet on the heart

The ketogenic diet presents several risks, particularly concerning cardiovascular health and safety. Although it has been shown to reduce blood pressure in the short term, this effect may be linked to increased dehydration and rapid weight loss, with limited evidence supporting long-term benefits. Furthermore, a 2023 meta-analysis indicates a moderate carbohydrate intake is associated with the lowest risk of cardiovascular mortality, while extremely low or high carbohydrate diets increase risk. So a low carbohydrate diet may result in unfavourable cardiovascular mortality outcomes when taken to ketogenic extremes.

The keto diet often leads to an increased consumption of animal fats and a reduced intake of fruits and vegetables. These deficiencies can exacerbate cardiovascular risks. Moreover, the diet’s tendency to cause greater fat-free mass loss and dehydration may harm elderly or malnourished individuals, potentially leading to adverse health outcomes.

Why the keto diet might affect heart rhythms

The keto diet has been seen to affect heart rhythms, particularly in individuals with or at risk for heart failure. Ketone bodies, produced in excess during ketogenesis, contribute to the body’s energy production. Although the heart typically adapts to shifts in fuel sources, elevated ketone levels can lead to favoring ketone metabolism over glucose and fatty acids. While potentially beneficial in energy-starved failing hearts, this metabolic shift could have unintended consequences for normal cardiac function, including disruptions in its electrical activity.

Furthermore, studies in animal models suggest that prolonged adherence to a ketogenic diet may lead to adverse myocardial remodeling, including fibrosis, and changes in the structural and functional properties of the heart. Such remodeling could interfere with the conduction of electrical signals within the heart, increasing the risk of arrhythmias such as Afib.

The electrolyte imbalance, potentially caused by the diet, may contribute to changes in potassium, sodium, and magnesium levels. Prolonged disturbances in these electrolytes can increase the likelihood of arrhythmias.

Although the ketogenic diet may offer benefits for metabolic health, such as improved glycemic control and reduced body weight, its potential impact on heart rhythms requires careful consideration.

Alternatives to the keto diet

The ketogenic diet is one of the many diet options out there. Other heart-healthy diets include the Mediterranean diet and the plant-based diet. The Mediterranean diet, rich in fresh produce, whole grains, olive oil, and moderate amounts of fish and meat, is associated with reduced cardiovascular disease and improved heart health, including a lower risk of Afib.

Similarly, a whole-foods plant-based diet, focused on unprocessed plant foods like vegetables, fruits, legumes, and whole grains, has been shown to reduce hypertension, diabetes, obesity, and inflammation, which are all key contributors to Afib. Reducing or eliminating processed and red meat, which increases hypertension, and limiting alcohol intake, are also recommended. These dietary strategies promote better overall heart health and may help manage or prevent Afib episodes.

Read more about nutrition and Afib in our article discussing heart-healthy diet options. 

The 2021 European Society of Cardiology guidelines on cardiovascular disease prevention recommend the Mediterranean diet for long-term benefits, highlighting its emphasis on nutrient quality, including low saturated fats and high intake of vegetables, fruits, and dietary fiber. While low-carbohydrate diets, including ketogenic diets, are mentioned as potential short-term strategies for weight loss and triglyceride reduction, their effects tend to diminish over time. The guidelines stress that ketogenic diets often lack essential nutrient quality and should be professionally supervised due to potential health risks. Further research is needed to evaluate its long-term efficacy and safety.