Irrespective of how it is prepared, coffee drinking significantly lowers the risk of incident cardiovascular disease and mortality
Coffee drinking, whether ground, instant or even decaffeinated, appears to lower the risk of incident cardiovascular disease and death according to the findings of a large analysis of data held within the UK Biobank database by Australian researchers.
Caffeine is widely consumed and it has been suggested that intake of tea and coffee, particularly in moderate doses, does not appear to be harmful and may even be beneficial in a range of cardiovascular conditions, including coronary artery disease, heart failure and arrhythmias. Nevertheless, this perception has not always been held within the medical profession. For example, in a 1998 survey of 697 medical specialists which sought to determine consensus on the harmful effects of caffeine, more than 75% recommended a reduction in caffeine in patients with anxiety, arrhythmias, oesophagitis or hiatal hernia, fibrocystic disease, insomnia, palpitations, and tachycardia. In contrast, more recently, evidence points towards a beneficial effect of coffee drinking in that it reduces the risk of coronary heart disease, heart failure, arrhythmia, stroke, CVD and all cause mortality. Whilst there is now a greater acceptance that drinking coffee is associated with health benefits, little is known about how the different methods of preparation e.g., instant, ground etc might impact on cardiovascular outcomes.
In the present study, the Australian team used data from the UK Biobank and categorised coffee drinking into the different subtypes (ground, instant, decaffeinated) and the divided intake as 0, < 1, 1, 2 – 3, 4 – 5 and > 5 cups of coffee/day. Cardiovascular outcomes examined were coronary heart disease, cardiac failure and ischaemic stroke. Using Cox regression modelling, the researchers also assessed the associations with incident arrhythmia, cardiovascular disease and overall mortality and results were adjusted for several factors including age, gender, alcohol intake, co-morbidities. They set the primary outcome as the relationship between coffee subtypes and incident arrhythmias, cardiovascular disease (CVD) and mortality.
Coffee drinking and cardiovascular outcomes
A total of 449,563 individuals with a median age of 58 years (55.3% female) were included in the analysis and followed for 12.5 years. A total of 100,510 served as non-drinking coffee controls.
All coffee subtypes were associated with a reduced risk of cardiovascular outcomes and the greatest reduction in risk occurred among those drinking 2 – 3 cups/day. For example, the risk of CVD was 10% lower (hazard ratio, HR = 0.90, 95% CI 0.87 – 0.92, p < 0.0001), 16% lower for ischaemic stroke (HR = 0.84) and 17% lower for cardiovascular mortality (HR = 0.83) with all reductions being statistically significant. Furthermore, the incidence of cardiac arrhythmias was also lowest among those drinking 2 – 3 cups/day.
When considering the different coffee subtypes, the greatest reductions were again observed for those drinking 2 – 3 cups/day and were significant for decaffeinated, instant and ground. However, there was no significant reduction in the risk of arrhythmia among those drinking decaffeinated coffee and in fact, there was a 14% higher risk of any arrhythmia in those drinking < 1 cup/day (HR = 1.14, 95% CI 1.04 – 1.26, p = 0.0068).
The authors concluded that consumption of 2 – 3 cups/day of any form of coffee reduced the risk of incident cardiovascular disease, arrhythmias and mortality. However, drinking decaffeinated coffee did not impact on the risk of arrhythmias and the authors added that mild to moderate coffee intake of all types should be considered as part of a healthy lifestyle.
Chieng D et al. The impact of coffee subtypes on incident cardiovascular disease, arrhythmias, and mortality: long-term outcomes from the UK Biobank Eur J Prev Cardiol 2022