2–3 cups of coffee daily may keep the heart healthy

Drinking 2–3 cups of coffee – be it ground, instant, or decaffeinated – daily is consistently associated with significant reductions in the risks of cardiovascular disease (CVD), coronary heart disease (CHD), congestive cardiac failure  (CCF), and all-cause mortality in a new analysis of the UK Biobank study.

Ground and instant coffee, but not decaffeinated coffee, was associated with a reduction in new-onset arrhythmias, including atrial fibrillation (AF).  

“Daily coffee intake should not be discouraged by physicians,” said author Dr Peter Kistler from the Alfred Hospital and Baker Heart and Diabetes Institute in Melbourne, Australia. “Instead, coffee should be considered a part of a healthy diet.”

Coffee – composed of over 100 biologically active components, including caffeine – is the most consumed psychostimulant. Previous studies support the health benefits of coffee, but there are only a  few dedicated ones on the impact of different coffee subtypes on incident arrhythmia, CVD, and mortality. [Trends Cardiovasc Med 2021;doi:10.1016/j.tcm.2021.08.004]

The current analysis sought to provide insights into the role of coffee on CV outcomes. Included were 449,563 participants (median age 58 years, 55 percent women) without arrhythmias or other CVD at baseline, who self-reported their coffee intake daily, including coffee sub-type. Non-coffee drinkers served as controls (n=100,510). About 27,809 individuals died over 12.5 years of follow-up, including 4,402 from CV causes. [Eur J  Prev Cardiol 2022;doi:org/10.1093/eurjpc/zwac189]

Coffee intake and arrhythmia

Compared with non-drinkers, a U-shaped relationship exists between increasing levels of coffee consumption and the incidence of arrhythmia. The lowest risk was seen in those who consumed 2–3 cups of coffee/day (HR, 0.91; p=0.0001).

For AF/flutter, significant risk reductions were seen in those who consumed 1–5 cups per day, with the lowest risk in those who consumed 4–5 cups/day (HR, 0.88; p<0.0001).

For ventricular tachycardia/ventricular fibrillation, increasing coffee intake was associated with a lower risk of incident arrhythmia, with the lowest risk seen with 4–5 cups per day (HR, 0.83; p<0.0201).

Incident CVD, CHD

Coffee consumption of up to 5 cups/day was also associated with reduced risks of incident CVD and CHD. The lowest risk for CHD was seen in those who consumed 2–3 cups/day (HR, 0.89; p<0.00001).

Coffee consumption at all levels was associated with reduced risks of CCF and ischaemic stroke. Again, the lowest risk was in those who consumed 2–3 cups/day (HR, 0.83; p<0.0001 for CCF and HR, 0.84; p<0.0001 for ischaemic stroke).

Mortality reduced

Death from any cause was significantly reduced with coffee intake of up to 5 cups/day; the greatest risk reduction was in those who consumed 2–3 cups/day (HR, 0.86; p<0.0001). Additionally, significant reductions in CV deaths were found in those who consumed up to 5 cups/day, with the lowest risk in those who consumed 1 cup/day (HR, 0.82; p<0.0001).

Coffee intake was not associated with the risk of sudden cardiac death.

Putative mechanisms

Kistler offered several putative mechanisms to explain the benefits of coffee on CVD. “Caffeine has antiarrhythmic properties through adenosine A1 and A2A receptor inhibition. It has also vasodilatory effects … and contains antioxidant polyphenols, which reduce oxidative stress and modulate metabolism.”

“Hence, coffee drinking should not empirically be discontinued even in those with underlying heart rhythm disorders or CVD,” Kistler said.

“We do not prescribe coffee to our patients,” said Dr Carl Lavie from the Ochsner Heart and Vascular Institute in New Orleans, Louisiana, US, who was not affiliated with the study. “But for the majority of those who like coffee, it is fine to take a few cups daily.”