The link between atrial fibrillation and diet

Atrial fibrillation is a common arrhythmic disorder where the heart beats quickly and irregularly. In this article, a consultant cardiologist 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 shortness of breath, chest pain, or wooziness. It can be an episodic occurrence 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 ranging from 100 to 175 beats per minute.

What causes atrial fibrillation?

Atrial fibrillation is in itself a symptom of structural dysfunction in the heart. It can be caused by several cardiac disorders such as:

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

And 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.
Some patients may feel that they 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, and heart failure due to strain.

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.

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

Cholesterol is a substance that is made by the body to structure cell membranes and in the production of some hormones and bile acids, and the surplus of it is introduced via food. While some extra cholesterol is not necessarily harmful, excess can begin to cling to the walls of blood vessels and obstruct blood flow, building up in the heart’s arteries. This means the heart has to work harder to get blood to flow throughout the body, and this is what can also lead to high blood pressure.

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 easily develop into type 2 diabetes, where the body cannot process insulin, the hormone that regulates blood sugar levels. Without the checks and balances of insulin control, high amounts of glucose in the blood can damage the blood vessels and the nerves in the heart, much like surplus cholesterol, by sticking to the red blood cells and causing build-ups, inhibiting sufficient oxygen supply to the heart. Patients with diabetes are also more likely to have high cholesterol.

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:

• Food that is high in saturated, or animal fats. For example, red meats like crackling pork or sausage
• Excessive salt or sugar like packaged crisps or chocolate bars
• Lard or ghee or butter
• Cream and hard cheese
• Cakes, cookies, and biscuits
• Food cooked with oils with omega-6 linoleic acids, such as seed oils like palm or coconut
• Deep-fried food
• Alcohol and caffeine

Instead, try to consume safer food such as:

• Nuts and seeds
• Avocados
• Oily fishes like salmon, trout, and mackerel
• Food with sunflower, rapeseed, olive and vegetable oils (high in Omega 3 fats, which are a healthy unsaturated fat)
• 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.