Coffee-holics can now feel especially good about drinking their daily morning brew.
A recent study found coffee drinking is linked to a longer life.
Researchers observed more than 208,000 participants over 30 years. Participants completed physical exams and surveys on diet and behavior, including their coffee habits.
The more coffee they drank, the lower their risk for heart disease, stroke, diabetes, suicide, and neurological diseases like Parkinson's.
For nonsmokers, the data is compelling:
- A daily cup of coffee was associated with a 6% decreased risk of early death.
- One to three daily cups was associated with an 8% decreased risk of early death.
- Three to five daily cups was associated with a 15% decreased risk of early death.
The coffee and longevity link persisted even when researchers controlled for age, alcohol consumption, and B.M.I. The association didn't hold true for smokers, however, probably because any minor potential benefits that come from coffee wouldn't be enough to counteract the long list of smoking-related diseases and health problems.
The researchers don't know exactly why coffee was linked to these benefits, but they now suspect it has nothing to do with caffeine. The study's participants who drank decaf saw the same benefits as those who drank caffeinated coffee.
The lead author, Dr. Ming Ding, of the Harvard School of Public Health, stressed that coffee was only linked to longevity. The study doesn't prove a direct cause-and-effect relationship.
"Our study is observational, so it’s hard to know if the positive effect is causal or not," she said in an interview with The New York Times.
Even if coffee is behind the observed benefits, the effects are relatively slight. "The differences in the chance of death between coffee drinkers and non-coffee drinkers, while statistically significant, are modest," the UK's National Health Service pointed out. Even if the study could prove cause-and-effect, "the results suggest that daily coffee consumption will do little for your long-term health if your general lifestyle is unhealthy."
Other studies have even suggested that coffee may be linked to health problems. In a 2013 study from Mayo Clinic Proceedings, researchers followed 43,727 participants for a median of 17 years. They found that people younger than 55 who drank more than four cups of coffee a day actually had an increased risk of heart disease. Again, it's impossible to say whether the coffee was behind that risk, or if there were other traits or behaviors shared by heavy coffee drinkers.
Most previous coffee research still shows a link between coffee drinking and positive effects, like decreased risk of stroke and Type 2 diabetes. Another recent analysis of nearly a million people also provided additional evidence linking coffee consumption to a reduced risk of early death.
While coffee doesn't guarantee a longer life — and caffeine can cause sleep problems and anxiousness — for most people, it certainly doesn't seem to hurt.
Join the conversation about this story »
NOW WATCH: The World Health Organization says there is ‘sufficient evidence’ that bacon causes cancer