Coffee May Be Part of the Recipe for a Longer Life
Study of More Than 400,000 Men and Women Links Coffee With a Lower Risk of Death
Although their study can't prove that coffee itself lowers drinkers' risk of dying, Freedman and his colleagues speculate about how it might. Caffeine probably is not a factor, he says, because death rates linked to decaf, preferred by a third of the coffee drinkers, were similar to those associated with caffeinated. But other compounds in coffee, such as antioxidants, might be important, the researchers write.
The researchers note several limitations of their study. For one, they lacked information about how the coffee was prepared, which could affect its compounds. And they asked about coffee consumption only once at the beginning of the study, but participants' habits might have changed over time.
"People do quit drinking coffee as they get older, or they switch to decaf ... because they don't sleep as well or they get palpitations," says Arthur Klatsky, MD, senior consultant in cardiology for Kaiser Permanente of Northern California. Klatsky was not involved with Freedman's research but has conducted his own studies of coffee and health.
"It's a big study with a remarkable result," Klatsky says. "It's a little bit hard to believe that coffee drinking is protective against all those different causes of death."
His own research found no such connection overall. Perhaps Freedman's study would have come up with different findings if it had enrolled a younger and more racially diverse population, Klatsky says.
While Freedman's team seems puzzled by the link between coffee drinking and a lower risk of death from accidents and injuries, including suicide, Klatsky says that one potential link "to me makes a little bit of sense." In this case, it probably is the caffeine, he says. "In people who are caffeine-addicted, it certainly brightens mood and staves off fatigue."
Freedman's study appears in The New England Journal of Medicine.