By Liz Szabo, USA TODAY
Coffee lovers are a loyal crowd. Most pour out their morning cup of java for the flavor, the aroma, and the accompanying jolt of energy, rather than the health perks.
So they may not mind if doctors debate new research suggesting that coffee lovers live longer.
According to an article in today's New England Journal of Medicine, those who drank coffee at the beginning of a 13-year study had a slightly lower risk of death than others, whether they chose decaf or full-strength.
Coffee drinkers also were a little less likely to die from specific causes: heart disease, respiratory problems, strokes, injuries and accidents, diabetes and infections. Coffee offered no protection against cancer.
But the benefits were modest - even among those with the heaviest coffee habit. Men who drank six or more cups of coffee day had a 10% lower overall risk of death than those who drank no coffee, while women who drank a similar amount had a 15% lower overall risk of death, according to the study, funded by the National Institutes of Health.
"It's interesting that coffee is more healthful than harmful," says Frank Hu, a professor at the Harvard School of Public Health, who has studied the health effects of coffee, but wasn't involved in the new study.
Not so fast, says cardiologist Steve Nissen, of the Cleveland Clinic, who also wasn't involved in the new research. Asking people about their coffee consumption only once in 13 years can be misleading, since drinking habits change. Nissen notes the study didn't include vital medical information that affects longevity, such as cholesterol or blood pressure levels.
"This study is not scientifically sound," Nissen says. "The public should ignore these findings."
Nissen found some of the statistical findings "bizarre." Inititally, he notes, researchers found that coffee drinkers had higher rates of death. Once scientists accounted for the fact that coffee lovers have higher rates of unhealthy habits, such as smoking, drinking and eating red meat, however, coffee drinkers appeared to live longer. That's a red flag that the study is deeply flawed, Nissen says.
Nissen also was skeptical of the conclusion that six cups of coffee could lower mortality by 10% to 15%. "We don't even have drugs that do that," Nissen says.
Scientists still have unanswered questions about coffee, which contains more than 1,000 compounds that can affect the risk of death, the study says.
Hu, however, say the study may at least suggest that coffee isn't harmful. "Just don't put in too much cream or sugar," Hu says. "They can wash all the benefit away."