Dr. John Day, Cardiologist

Does the Mediterranean Diet Prevent Atrial Fibrillation?

While researchers associate the Mediterranean diet with a lower risk of heart attacks and strokes, they continue to research its direct impact on preventing atrial fibrillation (AFib). In this article I review the latest study on how the Mediterranean Diet may prevent atrial fibrillation.

The PREDIMAR Study

Researchers conducted a study involving 199 patients from the PREDIMAR trial (PREvención con DIeta Mediterránea de Arritmias Recurrentes). The study aimed to explore the relationship between adherence to the Mediterranean diet and epicardial adipose tissue (EAT) in people with atrial fibrillation. EAT refers to the layer of fat surrounding the heart. They also investigated how EAT and MedDiet adherence correlated with AF recurrence after ablation.

How May the Layer of Fat Surrounding the Heart Cause AFib?

Now, you might wonder how this fat can cause atrial fibrillation. Well, researchers have found that when there’s too much fat around the heart, it can lead to inflammation. This inflammation can affect the electrical signals that control the heartbeat. When these signals become disrupted, they can cause the heart to beat irregularly, which characterizes what we see with atrial fibrillation.

Epicardial adipose tissue (EAT) is a type of fat that wraps around the heart, sitting between the heart muscle and its outer layer. It works like a cushion, protecting the heart. EAT is also active in the body’s metabolism, which means it can release hormones and substances that cause inflammation, potentially affecting heart health.

So, in simple terms, having too much epicardial adipose tissue (EAT) can lead to inflammation around the heart, which in turn can disrupt the heart’s normal rhythm and cause atrial fibrillation. That’s why it’s important to keep a healthy balance of fat around the heart to help maintain a regular heartbeat.

How May the Mediterranean Diet Decrease the Fat Layer Around the Heart?

The Mediterranean diet might help decrease epicardial adipose tissue (EAT) because it’s rich in foods that are good for the heart. Eating a mostly plant-based diet, rich in vegetables, fruit, and legumes, along with whole grains and lean proteins like fish in moderation, can have a positive effect on your body. Avoiding health-harming foods like sugar, processed foods, or fast foods is essential. This healthy eating pattern can benefit your overall health, including potentially shrinking the fat layer around the heart.

5 Ways that the Mediterranean Diet May Decrease Fat Around the Heart

1. Healthy Fats: The Mediterranean diet includes sources of healthy fats like olive oil, nuts, and fatty fish. We know that these fats have anti-inflammatory properties, which can help reduce inflammation in the body, including around the heart where EAT is located.

2. Vegetables, Fruits, and Legumes: The Mediterranean diet is packed with veggies, fruits, and legumes, which are rich in antioxidants and other nutrients. These nutrients can help protect the heart and reduce the risk of inflammation, which in turn may help decrease EAT levels.

3. Fiber: Plant-based natural foods like veggies, fruits, and legumes are packed with fiber. And a high fiber diet fills you up so you don’t need to snack between meals. Fiber is also good for heart health as it helps regulate blood sugar and cholesterol levels. And these blood sugar and cholesterol levels are factors that can influence EAT accumulation.

4. Lean Proteins: Lean proteins like fish and poultry in moderation are lower in saturated fats compared to red meat, which can help keep cholesterol levels lower and reduce the risk of excess fat and inflammation around the heart.

5. Overall Healthy Eating Pattern: The Mediterranean diet isn’t just about individual foods—it’s a lifestyle approach to eating. By following this pattern of eating, you’re less likely to consume processed foods, sugary drinks, and unhealthy fats, which can contribute to inflammation and EAT accumulation.

How Does the Fat Layer Around the Heart Correlate with Belly Fat?

Epicardial adipose tissue (EAT) and belly fat, also known as visceral adipose tissue (VAT), both constitute types of fat in the body, yet they reside in distinct areas and perform different functions.

EAT is the fat that surrounds the heart, located between the heart muscle and the outer layer of the heart. It acts as a protective cushion for the heart and is metabolically active, meaning it can release hormones and inflammatory substances that can affect heart health.

On the other hand, belly fat or VAT refers to the fat that accumulates around the abdominal organs, such as the liver, pancreas, and intestines. This type of fat associates with metabolic syndrome, insulin resistance, and an increased risk of cardiovascular disease.

Both EAT and belly fat can lead to health problems, but they aren’t directly linked. However, they can share some common risk factors, such as obesity, poor diet, sedentary lifestyle, and genetics. Individuals who have excess belly fat are more likely to have higher levels of EAT, but the relationship between the two can vary among individuals.

It’s important to note that reducing belly fat through lifestyle changes like healthy eating and daily exercise will likely also lead to a reduction in EAT.

How Do You Check Your Fat Layer Around the Heart?

The best way we can measure epicardial adipose tissue (EAT) is with directly imaging the heart. For example, an MRI or CT scan of the heart can readily identify the amount of epicardial adipose tissue (EAT). Unfortunately, physicians traditionally haven’t been taught about the link between the fat layer around the heart and the risk of atrial fibrillation, so you’ll rarely see the amount of EAT reported on an MRI or CT scan.

4 Main Findings of the Latest Study on the Mediterranean Diet and Atrial Fibrillation

The 4 main findings of this latest study on the Mediterranean Diet and atrial fibrillation can be summarized below:

1. The Mediterranean Diet is Associated with Less Epicardial Adipose Tissue (EAT): This research shows that adhering to the Mediterranean diet is linked to reduced levels of epicardial adipose tissue in individuals undergoing ablation for atrial fibrillation. This suggests that adopting a Mediterranean diet may help prevent the accumulation of EAT, which is associated with heart rhythm disturbances.

2. EAT is Associated with Persistent Atrial Fibrillation: Higher levels of epicardial adipose tissue are significantly associated with persistent atrial fibrillation, a more aggressive and challenging type of atrial fibrillation to treat. This underscores the importance of addressing EAT levels in individuals with atrial fibrillation, as it may impact the pattern and severity of the condition. In other words, the more EAT you have the harder it is to keep your heart in rhythm.

3. EAT Increases the Risk AFib After Ablation: The study suggests that a larger amount of epicardial adipose tissue may increase the risk of arrhythmic recurrence after ablation. This highlights the potential role of EAT in predicting the likelihood of recurrent episodes of atrial fibrillation post-treatment.

4. Mediterranean Diet Adherence May Help to Prevent AFib: While adherence to the Mediterranean diet shows a trend towards reducing the risk of arrhythmic recurrences after ablation, this association did not achieve statistical significance. However, in my experience, incorporating the Mediterranean dietary principles still offers many other benefits that are very helpful in managing atrial fibrillation.

Disclaimer

The information provided in this article is for educational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional before making any changes to your diet, exercise routine, or medical treatment plan.

About the Photo

Family fun in the sun! Enjoying a peaceful moment at the summit of the 9990 Chairlift at Park City Mountain Resort last weekend.