Coffee consumption is popular worldwide and is associated with reduced risk of cancer, diabetes, and Parkinson’s disease. However, the American College of Cardiology and American Heart Association recommend avoiding caffeine to reduce the risk of cardiac arrhythmias. Findings from a recent observational report suggest coffee consumption may reduce, not increase, the risk of cardiac arrhythmias.
Cardiac arrhythmias occur when the electrical impulses that control heart rate pulse too quickly, called tachycardia, or too slowly, called bradycardia. Coffee is the primary source of caffeine for most people. Because caffeine increases serum levels of catecholamines (e.g., adrenaline), it is plausible that coffee may increase the risk of cardiac arrhythmias. Although results from one observational study from 1980 support an increased risk of arrhythmias with increased coffee consumption, newer and more comprehensive evidence is needed.
The authors collected data regarding habitual coffee consumption and the incidence of cardiac arrhythmias from over 380,000 participants of the United Kingdom Biobank, a long-term registry study of United Kingdom citizens. The researchers assigned participants to one of eight categories of coffee consumption: zero, less than one, one, two, three, four, five, or six or more cups daily. Participants also provided a DNA sample for the sequencing of genes related to coffee metabolism.
Coffee consumption was associated with a reduced risk of cardiac arrhythmia. For each cup of coffee consumed daily, the risk of arrhythmia was reduced by three percent. This means an individual consuming three cups of coffee would have a nine percent risk reduction. This relationship was significant even after taking age, sex, race, metabolic health, smoking, alcohol and tea consumption, and exercise into account. Participants with genetic variants associated with slower caffeine metabolism drank less coffee, but did not have an increased risk of arrhythmia.
Greater coffee consumption was associated with a reduced risk of cardiac arrhythmias, a result that contradicts earlier evidence. Learn how coffee consumption may induce autophagy to improve other aspects of health in this clip featuring Dr. Guido Kroemer.