In a large, prospective, population-based community cohort study of 386,258 coffee drinkers, greater amounts of habitual coffee consumption were inversely associated with a lower risk of cardiac arrhythmia; in fact, each additional daily cup of coffee was associated with a 3% reduced risk of developing an arrhythmia; these associations were not significantly modified by genetic variants that affect caffeine metabolism. Kim et al. found no evidence...
