May 16, 2012 at 5:00 PM ET
Coffee drinkers who worry about the jolt of java it takes to get them going in the morning might just as well relax and pour another cup.
That’s according to the largest-ever analysis of the link between coffee consumption and mortality, which suggests that latte lovers had a lower risk of death during the study period.
“I would say it offers some reassurance to coffee drinkers,” said Neal Freedman, a nutritional epidemiology researcher at the National Cancer Institute. “Other studies have suggested a higher risk of mortality with coffee drinking and we didn’t see that in our study.”
In fact, men who drank at least six cups of coffee a day had a 10 percent lower chance of dying during the 14-year study period than those who drank none. For women, the risk was 15 percent lower, according to Freedman’s work, published in the latest issue of the New England Journal of Medicine.
Reassuring, indeed, for hard-core coffee drinkers like Spencer Turer, who guzzles four to six cups of coffee every day for personal consumption -- and sips between 75 and 300 cups more as part of his job as a professional coffee taster.
“It’s good news for all coffee drinkers because we can feel really good about the decisions we’re making,” said Turer, director of coffee operations for the firm Coffee Analysts, which provides unbiased scientific review of coffee products. “People concerned about the health effects may choose to drink more coffee.”
Overall, in the U.S. about 64 percent of adults drink coffee daily, according to Joe DeRupo, spokesman for the National Coffee Association. At 3.2 cups a piece, that amounts to some 479 million cups a day, agency figures indicate.
Those coffee fans can take the new results seriously. The mortality reduction is modest but solid, said Freedman, whose study offered the size and power to document associations other researchers had only suspected.
He and his team in NIC’s Division of Cancer Epidemiology and Genetics reviewed the coffee habits of more than 402,000 people followed between 1995 and 2008, including more than 52,000 who died.
They included some 229,000 men and more than 173,000 women ages 50 to 71 who agreed to take part in the NIH-AARP Diet and Health Study, which tracked comprehensive lifestyle questionnaires filled out by people in six states and two metropolitan areas.
Freedman’s analysis centered on healthy people; those with cancer, heart disease and stroke were excluded from the review.
“We didn’t know what to expect,” recalled Freedman. “There have been a lot of studies and the results have been mixed.”
Previous studies suggested that coffee might contribute to heart disease; others found similar results to Freedman’s, that coffee actually cut the risk of death. Initially, even Freedman’s study indicated a higher risk of death among coffee drinkers, but only because so many of them smoked cigarettes, too.
“It was only after we took into account people’s smoking that the association, the inverse association, revealed itself,” he said. “Smoking has a really strong association with death.”
Drinking six or more cups of coffee a day cut mortality risk the most, but not by much. People who drank between two and five cups of coffee daily also appeared to have lower risk, the study showed. Whether the coffee contained caffeine or not didn't seem to matter.
It's not clear whether -- or where -- the mortality effect tops out, but Freedman wasn't advising anyone to gulp 12 cups a day to test the theory.
The link to lower mortality held up whether researchers considered total deaths or deaths from specific diseases and other causes – except for cancer. When it came to cancer, deaths were slightly higher among male coffee drinkers.
Why? “We don’t know,” Freedman said.
The researchers also couldn’t say whether the lower risk of death could be because sick people and those with chronic diseases don’t tend to drink coffee.
Freedman is quick to emphasize that his study is an observational study, so it can note apparent ties between coffee drinking and decreased risk of death, but it can’t say whether coffee is the cause.
It might not even be the coffee itself that engenders the effect. Perhaps there's something about the act of making, serving or drinking coffee that protects people from death. It may be a soothing ritual, for instance, or it could engender more social contact, acts associated with lower risk of death.
Of course, there could be something beneficial about the drink itself, antioxidants, perhaps, or other elements that experts haven't detected yet.
"Coffee has more than 1,000 compounds and we really don't know what effects those compounds have on health," he said.
The study will be cheered as excellent news by coffee drinkers, especially healthy people and those in the six-cups-a-day crowd. But Freedman urges others to check with their doctors and use common sense.
“I don’t want people to read this and say, ‘Oh, I’m going to drink more coffee because I don’t want to die,’” he said. “We just don’t know whether it’s cause or effect.”
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