1 cup a day was associated with less recurrence of AF or atrial flutter compared with abstinence from coffee https://jamanetwork.com/journals/jama/fullarticle/2841253 1 cup of coffee reduces risk of atrial fibrillation https://scimex.org/newsfeed/cup-of-coffee-reduces-risk-of-irregular-heartbeat Kaffee vs Vorhofflimmern https://www.theguardian.com/us-news/2025/nov/10/coffee-irregular-heartbeat-protection-study