Consuming foods such as egg yolks and beef steak may increase the risk of developing atrial fibrillation, a dangerous heart rhythm problem that can trigger strokes, according to a new study.
Researchers found a link between the compound trimethylamine N-oxide (TMAO) and atrial fibrillation. TMAO is produced in the gut from nutrients like carnitine and choline, found in foods including egg yolks, beef steak, and pork.
The study, published in the Journal of Clinical Investigation, analyzed the blood cells of 5,000 individuals in the United States. Scientists discovered that participants with higher levels of TMAO in their blood had a 70 percent greater chance of developing atrial fibrillation compared to those with the lowest levels. This association remained significant even after accounting for other risk factors such as older age, high blood pressure, and obesity.
Atrial fibrillation causes the heart to beat irregularly and can lead to heart failure and stroke. Experts at the Cleveland Clinic, who were senior authors of the study, noted that current treatments primarily focus on managing the condition. However, their findings suggest potential for earlier intervention through dietary changes.
Experiments conducted on mice further investigated the link between TMAO and atrial fibrillation. Mice fed a diet that elevated TMAO levels developed the condition sooner than those on a standard diet. Similarly, mice given additional choline also showed an earlier onset of atrial fibrillation.
Researchers are exploring future treatments that could target gut bacteria to prevent the conversion of choline into TMAO. An experimental drug, iodomethylcholine, demonstrated in mice that it could delay the onset of atrial fibrillation by inhibiting this process. However, this drug has not yet been tested in humans.
The study authors emphasized that their findings provide additional evidence for the connection between heart health and the gut microbiome. Atrial fibrillation diagnoses have seen a notable increase, with a 50 percent rise in Britain between 2013 and 2023, according to the British Heart Foundation. The charity estimates that a significant number of people may have the condition without knowing it.
Previous research has also highlighted the risks associated with atrial fibrillation. A 2024 Danish study published in the British Medical Journal indicated that approximately 40 percent of individuals with atrial fibrillation are likely to develop heart failure during their lifetime, while around 20 percent are estimated to experience a stroke. Heart failure occurs when the heart cannot pump blood effectively. Cardiovascular diseases collectively cause a substantial number of deaths annually.
Symptoms of atrial fibrillation can include an irregular or rapid heartbeat, extreme fatigue, chest pains, reduced exercise capacity, shortness of breath, and fainting. The NHS advises individuals who suspect they have the condition to consult a general practitioner.