Over the past few months, three coffee studies made a lot of headlines in the news – “Drinking Coffee Every Day May Benefit Heart Health” and “The No. 1 Best Coffee Habit to Live Longer,” they read.
The headlines were based on two recent studies presented at the American College of Cardiology’s annual session. In one study, researchers reviewed health information from over 350,000 people, without cardiovascular disease, 57% women, to evaluate if coffee could be related to the development of heart disease or stroke during the 10 years of follow-up. They found that having two to three cups of coffee a day was associated with the greatest health benefits, translating to 10-15% lower risk of developing heart disease or dying for any reason.
The second study included nearly 35,000 people who had some form of cardiovascular disease and found that coffee consumption at two to three cups per day was associated with lower odds of dying compared to those who didn’t consume coffee. In addition, coffee consumption was not associated with a statistically increased risk of arrythmias.
The third study, Coffee and Real-time Atrial and Ventricular Ectopy (CRAVE), presented earlier at the American Heart Association Scientific Sessions 2021, took advantage of digital health tools and cardiac monitors to examine the effects of coffee consumption on ectopy burden (i.e. change in pattern of heartbeats that could result in skipped or extra beats). The study consisted of 100 healthy volunteers, average age 38 years old. The participants in the study served as their own controls consuming as much coffee as they wanted to on alternate days and avoiding caffeine the other days. While there were no significant differences in burden of premature atrial contractions, participants experienced on average 54% more premature ventricular contractions on days they consumed coffee. No significant relationships were observed to ventricular tachycardia or other arrhythmias.
How relevant is this information for patients?
Although the questions of what constitutes a healthy amount of coffee consumption and what are the long-term health outcomes associated with this are compelling and important, we can draw limited conclusions from these studies so far. The reasons for this have to do with the nature of the studies and the way the data was collected.
Two of the studies were observational, meaning patients were not randomly assigned to groups of coffee drinkers and non-coffee drinkers, but rather information was obtained from large medical databases and the data was analyzed by group. This limits the ability to account for some variables that may affect the outcomes studied.
In addition, in all of the studies, patients were asked to self-report the amount of coffee they drank which introduces additional variables regarding accuracy of reporting and definitions of coffee amount.
Thirdly, the majority of participants in these studies were healthy and younger individuals (under age 65) and without significant comorbidities, potentially limiting the applicability of the findings to older patients.
The bottom line:
I commend the study researchers and clinicians on providing us an important initial look at the effect of coffee on health and cardiovascular health. As a cardiologist and clinician, I would advise patients to discuss the question of healthy coffee consumption with their doctor.
If you’re already a healthy person who drinks coffee and feels well, there is no reason to make any changes. Similarly, if you’re a healthy person who doesn’t drink coffee, there’s no reason to pick up the habit now. We have yet to more definitively study the health effects of coffee in patients with cardiovascular disease.
About the Author
Anna Koulova, MD, FACC, is a cardiologist and the Director of Cardiac MRI at Stamford Health.
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