Coffee is one of the most frequently consumed drinks, with more than 2 billion cups served worldwide each day. In a national survey, three out of every four adults drink coffee and half of all adults drink it every day.
Two new studies, one from the U.S. and one from Europe and published in the Annals of Internal Medicine, suggest an association between coffee consumption and better health.
In the first study, Dr. Song-Yi Park, an associate member of the University of Hawaii Cancer Center, and colleagues analyzed survey data from approximately 185,000 people in the U.S. between 1993 and 1996. The participants were between ages 45 and 75, and were asked about their coffee consumption at baseline.
They were then followed from enrollment until 2012 to assess for the association between coffee consumption and the rate of death. After controlling for differences like smoking status, education and pre-existing illness, researchers found that as the amount of coffee consumption increased, the risk of death decreased in the cohort.
In the second study, Dr. Marc Gunter, a faculty member at the School of Public Health at the Imperial College London, and colleagues analyzed survey data from about 450,000 people in 10 European countries who enrolled between 1992 and 2000. Patients were followed for an average of 16 years, and the association between coffee consumption and the rate of death was assessed.
Researchers controlled for differences between participants and found that as the amount of coffee consumption increased, the risk of death in the cohort decreased.
Park’s and Gunter’s studies add to the evidence coffee may be part of a healthy lifestyle. Both studies showed the group that drank the most coffee (four or more cups in the U.S. study and three or more cups in the European study) had the largest reduction in mortality.
It is important to remember both studies show an association between coffee and lower mortality rate, but neither shows coffee causes a lower mortality rate. For example, if someone is an athlete, he or she might go to the gym often. An association, like both of the above studies, is that a gym membership is associated with being an athlete. It would be incorrect to conclude a gym membership causes one to become an athlete, as there are many people who go to the gym and are not athletes.
As such, the biggest message from both papers is coffee is associated with lower mortality and if one is drinking coffee, including three or more cups a day, it is likely a reasonable beverage for one’s overall health. For the coffee drinkers out there, it is a nice pat on the back. For those who don’t drink coffee, unfortunately we need more research before advising whether to start.
Anant Mandawat, a graduate of Lakeside High School and Yale University’s medical school, is a doctor of internal medicine at Massachusetts General Hospital.