“We are the first study to point to a mechanism by which a lifestyle factor can sharply alter the electrical properties of the heart to increase the chance of arrhythmia,” said Dr. Gregory Marcus, Associate Professor of Cardiology for Research at the University of California, San Francisco.
The research on atrial fibrillation, published Wednesday in the Journal of the American College of Cardiology: Clinical Electrophysiology, was unique in that it was a randomized, double-blind clinical study – considered the “gold standard” in research.
Marcus and his team put 100 heart patients diagnosed with AFib – the most common life-threatening heart rhythm disorder – under anesthesia and then injected them with enough alcohol to bring their blood alcohol level to 0.08% – just above the legal limit in the United States.
The change they saw was frightening: alcohol seems to immediately affect the heart’s natural recovery period in a way that can cause atrial fibrillation.
“The electrical changes we observed in the pulmonary veins … would increase the chance that atrial fibrillation would occur immediately, and that it would be maintained,” Marcus said.
“This is a first human demonstration of the immediate effects of alcohol, directly on the heart,” said Dr. Marco Perez, director of the Inherited Cardiac Arrhythmia Clinic at Stanford University Medical Center, said, who was not involved in the research.
“However, this study does not address the question of whether moderate drinking is ‘good or bad’ for the heart, especially not in the long term,” Marcus added. “It just helps us to understand the possible mechanisms behind the observations that people who drink have higher rates of arrhythmias.”
A growing concern
AFib is an irregular heartbeat often described by many sufferers as a ‘quiver’, ‘flutter’ or ‘flip-flop’ of the heart in the chest.
It can lead to blood clots, heart failure and other heart related complications.
“It can also increase the risk of heart attack, dementia, kidney disease. All of these things are probably long-term risks,” Marcus said.
“Age is one of the most important risk factors, and with the aging of the population, it is becoming more common,” Marcus said.
The obesity epidemic is also contributing to the growing numbers, along with other risk factors such as high blood pressure, diabetes, chronic kidney disease, smoking and yes, drinking alcohol.
“There is a long history of evidence that alcohol can increase the risk of atrial fibrillation, as opposed to the findings regarding coronary arteries or the risks of a heart attack,” Marcus said.
This, of course, flies in the face of what we have often said in the past – drinking moderately can actually help the heart.
“This is a critically important distinction,” Marcus said. ‘Many people in the layman’s community easily combine different types of heart disease, and make the assumption that when one refers to heart disease, it means a heart attack or a blockage of a coronary artery that supplies blood to the heart.
“So it could very well be the case that alcohol – at least in moderation – can be healthy for some types of heart disease and harmful for other types of heart disease,” Marcus said.
- CNN Interactive: Do you drink too much?
Is alcohol really good for the heart?
However, some studies are beginning to question the benefits of alcohol for the heart.
‘There are studies that report a benefit for moderate drinking, but these are not’ random, controlled ‘studies, and are probably confused by the fact that people who drink a moderate to moderate drink have other benefits (such as exercise) can do what is good. for the heart, ‘Perez said in an email.
“However, there are some genetic studies that suggest that even moderate alcohol use has a detrimental effect on clinical outcomes,” Perez added.
According to Bell, the ‘home message’ from his study is that ‘people should not drink under the belief that it will lower their risk of disease.’
“And those among us who prefer to drink should reduce our intake if we want to prolong our life and well-being,” Bell said.