There’s more evidence that consumption of two to three cups of coffee per day, whether decaffeinated, ground or instant, is associated with a reduction in incident CVD and mortality – but some benefits are dependent on the type of brew consumed.
UK Biobank data from more than 400,000 participants over a median follow-up period of 12.5 years showed significant reductions in the risk of incident CHD associated with habitual coffee intake of up to 5 cups/day, with the lowest risk in those who consumed 2–3 cups/day (HR 0.89, CI 0.86–0.91, P < 0.0001).
Coffee consumption at all levels was also associated with a significant reduction in the risk of CCF and ischaemic stroke – the lowest risk observed in those who consumed 2–3 cups/day, with HR 0.83 for CCF (CI 0.79–0.87, P < 0.0001), and HR 0.84 for ischaemic stroke (CI 0.78–0.90, P < 0.0001).
The lowest risk for arrhythmias was seen in those who consumed 2–3 coffee cups/day, with a HR 0.91.
“For AF/flutter, significant risk reductions were seen in those who consumed between 1 and 5 cups/day, with the peak risk reduction seen in 4–5 cups/day (HR 0.88, CI 0.83–0.94, P < 0.0001).”
“For VT/VF, increasing coffee intake was associated with lower risk of incident arrhythmia, with the lowest risk seen in 4–5 cups/day (HR 0.83, CI 0.70–0.97, P = 0.0201).”
The study, published in the European Journal of Preventive Cardiology [link here], said a significant reduction in all-cause mortality was associated with coffee consumption up to 5 cups/day, with the greatest effect seen with 2–3 cups/day (HR 0.86, CI 0.83–0.89, P < 0.0001).
When analysing the data according to coffee subtype, arrhythmia reduction was seen with caffeinated but not decaffeinated coffee.
However all three coffee subtypes were associated with a significant reduction in CVD, CCF, CHD, stroke, and CV/all-cause mortality.
The study authors said coffee was a complex compound of more than a hundred biological active components including caffeine.
“Mild–moderate coffee intake of all types should not be discouraged but rather considered part of a healthy lifestyle,” the investigators concluded.
Nutritionists commenting on the observational study warned that it was difficult to directly attribute the cardiac outcomes to self-reported behaviours in coffee consumption.
Dr Annette Creedon, Nutrition Scientist and Manager at the British Nutrition Foundation, said many aspects of the participants’ diet and lifestyle may also have changed over the 12.5 year course of the study.
“Non-coffee drinkers served as controls in this study, but it is unclear whether they consumed caffeine from other dietary sources (e.g. tea or other drinks) and if so, whether they consumed a comparable quantity of caffeine. Hence, it is possible that differences observed between the control group and the test group may be due to factors other than the coffee subtype.”
“The authors do acknowledge that drinking caffeinated coffee can result in some negative side effects for some individuals and this can be particularly relevant to individuals who are sensitive to the effects of caffeine. Hence, the findings of this study do not indicate that people should start drinking coffee if they do not already drink it or that they should increase their consumption.”
Dr Charlotte Mills, Hugh Sinclair Lecturer in Nutritional Sciences at the University of Reading, said randomised controlled trials were needed to fully understand the relationship between coffee and health before recommendations could be made.
“This manuscript adds to the body of evidence from observational trials associating moderate coffee consumption with cardioprotection, which looks promising. However, with observational research like this, you can’t be sure what direction the relationship goes e.g. does coffee make you healthy or do inherently healthier people consume coffee?”