It’s the news that coffee addicts have been waiting for: Drinking several cups of coffee every day may help you live longer. A study of more than 400,000 people finds that drinking coffee may reduce the risk of death from heart disease, stroke and even infections, researchers report in the May 17 New England Journal of Medicine.
Scientists have long puzzled over the notion that a stimulant could provide a health benefit. “There’s been a concern for a long time” that coffee could even be detrimental, says study coauthor Neal Freedman, an epidemiologist at the National Cancer Institute in Bethesda, Md. “Our results might provide some reassurance for long-term coffee drinkers.”
Since the study volunteers weren’t randomly assigned to drink coffee or not, the research has the limitations of being observational in nature. But with data from 402,260 participants, the results are “very powerful” and unlikely to be superseded by another coffee study anytime soon, says Roy Ziegelstein, a cardiologist at the Johns Hopkins Bayview Medical Center. “This might be as good as it gets,” he says.
Freedman and his colleagues analyzed data provided by men and women who completed a detailed questionnaire that included information about coffee intake as part of a medical study in the mid-1990s. The researchers excluded people who had previously had cancer, heart disease or some other serious illness and recorded the remaining volunteers’ mortality status through 2008 by checking death records.
During a median follow-up of 13.6 years, people who drank two or more cups of coffee per day were 10 to 16 percent less likely to have died than nondrinkers. A single cup a day provided less apparent benefit. Women seemed to get more out of drinking ample java than men; women who drank six cups of coffee per day had a 15 percent reduced risk of death compared with nondrinkers, while men consuming that much had only a 10 percent reduced risk.
More than two cups a day seemed to offer some protection against death due to heart disease, respiratory ailments and diabetes, while four or more cups a day imparted apparent benefits against stroke and infections.
The researchers accounted for differences between coffee drinkers and nondrinkers such as body mass, smoking status and the consumption of alcohol, red meat, white meat, vitamins, fruits and vegetables.
Caffeine may not play a big role in coffee’s apparent benefit. Decaffeinated coffee consumption was associated with about the same longevity edge as regular. “There are a huge number of chemically active components aside from caffeine in coffee,” says Rachel Huxley, an epidemiologist at the University of Minnesota School of Public Health in Minneapolis. “Given that the relationship between coffee intake and reduced mortality is not confined to one particular disease suggests that there are a lot of possible mechanisms involved.”