The link between atrial fibrillation and diet

Atrial fibrillation is a common arrhythmic disorder where the heart beats quickly and irregularly. In this article,  consultant cardiologist Dr Boon Lim explores how diet can impact atrial fibrillation.

What is atrial fibrillation?

During atrial fibrillation (AFib), the atria, which are the heart’s upper chambers, begin to beat rapidly and out of sync with the ventricles, the lower heart chambers. This may lead to sensations of palpitations, shortness of breath, chest pain, or dizziness. It can be an episodic occurrence (which is termed paroxysmal) or persistent. The arrhythmia happens due to an error in transmitting bioelectrical signals across the heart’s four chambers (the two atria and the two ventricles). Where a normal resting heart rate is typically between 60 and 100 beats per minute, patients with AFib can have a resting heart rate which is much higher than usual, typically between 90 and 140 beats per minute, but with the heart rate accelerating rapidly, sometimes it can go up to rate of 180 to 200 beats per minute during minimal exertion.

What causes atrial fibrillation?

Atrial fibrillation is a heart rhythm abnormality, but there is likely to be a structural heart abnormality which contributes to the development of AFib. What are the major factors for the development of AFib?

• Valvular heart disease, where the heart’s valves are leaking or narrowed
• Heart attacks and damage from prior heart attacks
• High blood pressure

Other conditions that affect the heart’s health can also cause complications that lead to AFib, such as:

• Obesity
• Substance abuse
• Type 2 diabetes
• Hyperthyroidism
• Obstructive sleep apnoea

Patients with AFib have reported that episodes can be triggered due to high stress or physical activities, drinking caffeine or alcohol, and after large meals. This form of AFib is termed ‘vagally mediated AFib’ and you can learn more about this by watching this video.

Some patients may feel that they are not too negatively impacted by their condition, but AFib comes with significant risks that can be fatal or at least massively debilitating, including blood clots forming that can lead to a stroke, heart failure causing shortness of breath, and inability to catch your breath with minimal exertion.

What is the relationship between atrial fibrillation and diet?

One of the key tenets for maintaining a healthy heart is a healthy diet – and this extends to preventing AFib.

Avoid foods which are known to trigger AFib  - an individualised approach (understand your triggers of AFib!)

Some patients will be aware of certain food triggers. In other words, particular types of food or drink may trigger an episode of AFib either within an hour, or perhaps several hours later, and occasionally during sleep. The common food triggers include:

• Alcohol – particularly in binges or in combination with large meals
• Caffeine – either in coffee/tea or even chocolate
• Large “stodgy” or carbohydrate-laden meals – ie large volume meals which stretch and distend the stomach may well trigger vagally-mediated AFib.

A specific nuance concerning acute food triggers of Afib includes trying to figure out what specific combination of conditions facilitates the food that triggers AFib. For example, taking two glasses of wine on a relaxing day at the end of the evening and after a healthy light meal may not trigger a bout of AF. However, the same two glasses of wine, consumed after a heavy day at the office, followed by an intense workout, and followed by a large meal, may well have a much higher likelihood of triggering AF in the 6 hours afterwards

Avoid foods that stack your risk factors for developing Afib

Obesity and type 2 diabetes, for example, are conditions that are caused by or worsen due to unhealthy diets that are high in sugar and processed foods, and low in nutritional value.

An unhealthy diet with a lot of sugar means that the blood sugar (glucose) levels are too high. If they are constantly high it can lead to a stepwise development in insulin resistance, followed by the development of type 2 diabetes, where the body cannot process glucose effectively.

Without the checks and balances of good insulin control, high amounts of glucose in the blood can damage the blood vessels, leading to coronary atherosclerosis, which may increase your risk of a heart attack which may weaken the heart muscle. This will increase your risk of Afib.

In addition, consuming an unhealthy diet rich in high-sugar and ultra-processed foods may lead to obesity, which in itself increases the risk of diabetes, obstructive sleep apnoea, and hypertension, all of which are factors that increase the likelihood of developing Afib.

Thus, it is clear to see how AFib and other forms of heart damage can manifest or be triggered as a result of a diet that is suboptimal.

What changes to my diet can I make to help with atrial fibrillation?

In order to prevent or avoid triggering AFib, it is recommended to eat less:

• Excessive salt or sugar like packaged crisps or chocolate bars
• Ultra-processed foods (cakes, cookies, and biscuits)
• Deep-fried food
• Alcohol and caffeine (if these are known triggers)

Instead, try to consume healthy food such as:

• Nuts and seeds
• Avocados
• Oily fishes like salmon, trout, and mackerel
• Sautéed or boiled food
• More fibre and wholegrain foods
• More fresh fruit and vegetables

A healthy diet can reduce the chances of developing AFib by minimising the risk of high blood pressure, mitigating the effects of diabetes type 2, facilitating weight loss and combating obesity, and improving blood flow to the heart and reducing blood sugar and cholesterol levels.