If you ever felt that you needed coffee to survive, you may be onto something.
Drinking coffee is linked to lower death rates, according to two large studies published Monday in the journal Annals of Internal Medicine.
Coffee is one of the most widely consumed beverages in the world, and its potential health benefits have been the subject of curiosity for decades. Previous research suggested that drinking coffee regularly may be tied to a lower risk of diabetes and cardiovascular disease. Now there is evidence that it might have a broader effect, staving off other potential causes of death as well.
One study examined the coffee-drinking patterns of more than 185,000 Americans over 16 years. The researchers found that regular coffee consumption was associated with lower death rates from all causes — and the more cups of coffee the subjects consumed per day, the greater the apparent benefit. In fact, those who reported drinking four or more cups per day enjoyed an 18 percent lower chance of death over the study period than those who said they drank no coffee.
In a second study, researchers in Europe looked at more than 520,000 people across 10 countries over 16 years. This study, too, found that those who drank several cups of coffee a day had lower death rates, regardless of country.
Both studies took into account smoking and other factors that could have affected the results.
“I was surprised by how consistently our findings fit in, relative to what has been previously published,” said Veronica Setiawan, the lead author of the U.S. study and an epidemiologist at the Keck School of Medicine at the University of Southern California. “It’s surprising and very reassuring. More than half of Americans drink coffee, so it’s very important to understand its health impact.”
Setiawan, who said she drinks a cup or two of coffee each day, added that her study was the first of this scale to measure the possible effects of coffee consumption across a racial and ethnic spectrum. Her team found that coffee was associated with fewer deaths due to heart disease, cancer, respiratory disease, stroke, diabetes and kidney disease — a finding that was true across a variety of ethnic groups, including African-Americans, Caucasians, Japanese-Americans and Latinos.
But when it comes to whether we can conclusively call coffee an elixir for long life, other researchers say the science still needs to percolate.
“We’re not at the point where we can say with full confidence that it’s protective,” said Dr. Eliseo Guallar, a professor at the Johns Hopkins University Bloomberg School of Health, who co-authored an accompanying editorial. “But the basic idea is that we are increasingly reassured that coffee is not harmful. As doctors, we don’t have to tell people to be worried about drinking coffee anymore. Now we can tell people to drink their coffee and be happy.”
Interestingly, in the U.S. study, even decaffeinated coffee was found to be linked to longer life, suggesting that the mechanism for its health benefits lies somewhere other than caffeine. Coffee contains many bioactive chemicals, including those with antioxidant effects, that have been shown to benefit health.
In the U.S., retail coffee sales are roughly $48 billion a year, so the news that the beverage might do far more than just wake people up has important implications.
Trisha Pasricha, M.D., is an internal medicine resident at the Johns Hopkins Hospital.