Coffee good for heart health – Large study

Coffee good for heart health – Large study

Usually physicians, including me, ask patients with cardiovascular disease to avoid coffee, especially for those with cardiac arrhythmia [1]. Now, here is a study which says that taking 2-3 cups of decaffeinated, ground or instant coffee a day is associated with significant reductions in incident cardiovascular disease and mortality. Even more, ground and instant coffee, but not decaffeinated coffee was associated with reduced arrhythmia [2].

In fact, coffee consumption at 3-4 cups per day has been described as probably not harmful and perhaps even moderately beneficial in the 2021 European Society of Cardiology prevention of cardiovascular disease guidelines. But they have mentioned that non-filtered coffee contains LDL cholesterol raising cafestol and kahweol and may be associated with 25% increased risk of mortality due to atherosclerotic cardiovascular disease by consumption of nine or more drinks per day! [3].

The UK Biobank study recruited participants aged 40 to 69 years between 2006 to 2010. There were 449 563 participants in the final study cohort after various exclusions. Median age was 58 years and median follow up was 12.5 years. 100,510 non-coffee drinkers served as controls. 6.7% of the participants had arrhythmia, which included 3.4% of atrial fibrillation or flutter, 0.7% of supraventricular tachycardia, and 0.4% of ventricular tachycardia or fibrillation. Compared with non-drinkers, a U-shaped relationship was seen between increasing levels of coffee consumption and incidence of any arrhythmia [2].

After adjustment for multiple covariables, lowest risk for arrhythmias was seen in those who consumed 2-3 cups of coffee per day. There was some variation between the types of arrhythmias and the optimal level of consumption.

Incident coronary artery disease was diagnosed in 7.7% of the participants. Incident congestive heart failure occurred in 2.8% and incident stroke in 1.5%. Lowest risk for coronary artery disease was observed in those who consumed 2-3 cups of coffee per day. Similar figures were noted for congestive heart failure and ischemic stroke as well. Greatest reduction in mortality was also noted at 2-3 cups of coffee per day.

44.1% of the participants used instant coffee while 18.4% used ground coffee and 15.2% used decaffeinated coffee. In case of ground coffee, all cause mortality was lowest at 2-3 cups per day while cardiovascular mortality was lowest at 4-5 cups per day. U-shaped relationship was noted between all subtypes of coffee and all cause mortality. 2-3 cups per day of instant coffee was associated with the lowest risk for any arrhythmia. Effect of decaffeinated coffee on any type of arrhythmia was neutral in this study.

Coffee is composed of more than 100 biologically active components of which caffeine is the most well recognized. Acute caffeine intake results in sympathetic activation mediated by inhibition of phosphodiesterase, calcium release within the cells and stimulation of release of sympathomimetic amines [4]. But habitual coffee consumption has not been shown to result in changes in heart rate, ECG parameters or heart rate variability [5].

One cup of coffee contains about 95 mg of caffeine, while energy drinks often contain much higher levels and have been associated with adverse events. Antiarrhythmic properties of caffeine are mediated through inhibition of adenosine A1 and A2A receptors [2].

National Institutes of Health-AARP Diet and Health Study had checked the association of coffee drinking and subsequent total and cause specific mortality among 229,119 men and 173,141 women. The study was conducted between 1995 and 2008. Authors concluded that coffee consumption was inversely associated with total and cause specific mortality. But they could not determine whether this was a causal or associational finding [6].

References

1. Hughes JR, Amori G, Hatsukami DK. A survey of physician advice about caffeine. J Subst Abuse. 1988;1(1):67-70. doi: 10.1016/s0899-3289(88)80009-9. PMID: 2485281.
2. Chieng D, Canovas R, Segan L, Sugumar H, Voskoboinik A, Prabhu S, Ling LH, Lee G, Morton JB, Kaye DM, Kalman JM, Kistler PM. The impact of coffee subtypes on incident cardiovascular disease, arrhythmias, and mortality: long-term outcomes from the UK Biobank. Eur J Prev Cardiol. 2022 Sep 27:zwac189. doi: 10.1093/eurjpc/zwac189. Epub ahead of print. PMID: 36162818.
3. Visseren FLJ, Mach F, Smulders YM, Carballo D, Koskinas KC, Bäck M, Benetos A, Biffi A, Boavida JM, Capodanno D, Cosyns B, Crawford C, Davos CH, Desormais I, Di Angelantonio E, Franco OH, Halvorsen S, Hobbs FDR, Hollander M, Jankowska EA, Michal M, Sacco S, Sattar N, Tokgozoglu L, Tonstad S, Tsioufis KP, van Dis I, van Gelder IC, Wanner C, Williams B; ESC National Cardiac Societies; ESC Scientific Document Group. 2021 ESC Guidelines on cardiovascular disease prevention in clinical practice. Eur Heart J. 2021 Sep 7;42(34):3227-3337. doi: 10.1093/eurheartj/ehab484. Erratum in: Eur Heart J. 2022 Sep 09;: PMID: 34458905.
4. Chieng D, Kistler PM. Coffee and tea on cardiovascular disease (CVD) prevention. Trends Cardiovasc Med. 2022 Oct;32(7):399-405. doi: 10.1016/j.tcm.2021.08.004. Epub 2021 Aug 9. PMID: 34384881.
5. Voskoboinik A, Koh Y, Kistler PM. Cardiovascular effects of caffeinated beverages. Trends Cardiovasc Med. 2019 Aug;29(6):345-350. doi: 10.1016/j.tcm.2018.09.019. Epub 2018 Oct 4. PMID: 30301595.
6. Freedman ND, Park Y, Abnet CC, Hollenbeck AR, Sinha R. Association of coffee drinking with total and cause-specific mortality. N Engl J Med. 2012 May 17;366(20):1891-904. doi: 10.1056/NEJMoa1112010. Erratum in: N Engl J Med. 2012 Jul 19;367(3):285. PMID: 22591295; PMCID: PMC3439152.