Coffee is the second most consumed beverage in the world after water. In fact, 2.25 billion cups of coffee are consumed worldwide every day. The average American spends about $1100 annually on coffee. So, what is the data around drinking coffee and the risk of death?
This question was examined in a prospective study of 10 European countries. The study consisted of 521,330 participants enrolled in the EPIC (European Prospective Investigation into Cancer and Nutrition) trial. The participants had a 16.4-year follow-up.
What was interesting about the study was that the highest coffee consumers tended to smoke more, exercise less, eat fewer fruits and vegetables, and drank more alcohol.
The authors found that comparing men with the highest versus lowest coffee consumption, there was a 12% reduction in all-cause mortality. Similarly, in women, there was a 7% reduction in all-cause mortality.
Then they looked at those drinking 3 or more cups per day versus none. The authors found that men had an 18% reduction in risk of death and women had an 8% reduction in risk of death.
In all these comparisons, there was no difference in the results noted for those drinking caffeinated or decaffeinated coffee.
The results got even more interesting when looking at digestive diseases. Highest versus lowest coffee consumption in men had a 59% reduction in the risk of death from digestive diseases. Women had a 40% reduction in the risk of death from digestive diseases.
In liver disease mortality, highest versus lowest consumption had an 80% reduction in risk for both men and women combined. Even in cirrhosis, mortality was reduced by 79% for both men and women combined.
The authors postulated that coffee’s protective effects on the liver may be due to data from other studies showing that it can decrease cell growth, increase cell death, and decrease cells sticking together. These activities can help get rid of bad cells quickly. Coffee has also been showing to reduce fat, lower oxidative stress and lower inflammation in the liver. However, this data comes to us from mouse models.
One concerning finding in this study was an increase in ovarian risk of 31% in women with the highest coffee consumption. This association has not been seen in any of the other large trials that I have reviewed.
There were also some important limitations in this study to keep in mind. First, not all centers collected data on caffeinated versus decaffeinated coffee. Also, a lot of people drink both and this can make the distinction even more complex. Second, even though the authors adjusted for variables, there can still be some things present that weren’t adjusted for and can affect the results. Third, this is a large study but looking at European population. The results may not apply to the result of the world. Lastly, this is a correlation study and not proving causation.
Despite these limitations, this study together with previous studies, shows that drinking caffeinated or decaffeinated coffee may lower our risk of death from all causes and from digestive diseases.
Gunter, M. J., et al. (2017). “Coffee Drinking and Mortality in 10 European Countries: A Multinational Cohort Study.” Ann Intern Med 167(4): 236-247.