New studies counter fears that coffee is bad for you.
If you grew up thinking coffee was a guilty pleasure, you can stop feeling guilty and pour yourself another cup o joe. In the largest study of its kind-more than 400,000 people- both men and women coffee drinkers were less likely to die over a 13-year span than non-coffee drinkers. Choosing regular or decaf made no difference, suggesting caffeine isnt the key. The more coffee people drank-up to six cups a day-the less likely they were to die during the study period.
The association between coffee consumption and reduced mortality was modest-at most, 12% for men and 16% for women drinking four or five cups a day. But the biggest concern for a long time has been that drinking coffee is a risky thing to do, says lead researcher Neal Freedman, PhD, of the National Cancer Institute. Our results, and some of those of more recent studies, provide reassurance for coffee drinkers that this isnt the case.
Freedman and colleagues looked at data on 229,110 men and 173,141 women participating in the National Institutes of Health-AARP Diet and Health Study, which began in 1995. By 2008, 52,515 of the study participants had died. Participants were initially ages 50 to 71, and all except about 10% drank coffee-an average of two or three cups a day, with two-thirds preferring regular. Coffee consumption was recorded only once, at the start of the study, but Freedman notes that other research has shown that people tend to be consistent with their coffee drinking.
Coffee drinkers in the study were actually less healthy in their habits than their peers-more likely to smoke, eat lots of red meat and drink alcohol, while less likely to exercise and eat enough fruits and vegetables. When scientists initially adjusted the mortality data only for age, these lifestyle factors masked the good news about coffee; drinking coffee was associated with an increased risk of dying. But when Freedman and colleagues took those factors into account, a link between coffee and reduced mortality emerged.
In addition to lower overall mortality risk, coffee drinkers were less likely to die from heart or respiratory disease, stroke, diabetes, infections and even injuries and accidents. Only cancer deaths showed no such correlation.
The study cant prove that drinking coffee contributes to longevity, and experts who commented on the results generally advised this isnt reason to start drinking coffee if you dont already.
Jeffrey B. Blumberg, PhD, director of Tufts HNRCA Antioxidants Research Laboratory, says its biologically plausible for compounds in coffee, such as polyphenols, to have a protective effect on health. Its most likely the chlorogenic acids, he adds, while noting that your simple cup of coffee contains a complex mix of biologically active compounds.
The NIH-AARP results capped a series of recent studies on coffee and health that should have Juan Valdez jumping for joy. Late last year, Chinese researchers reported in the Journal of Agricultural and Food Chemistry that compounds in coffee may inhibit the formation of protein compounds that contribute to the death of cells in the pancreas, which produces insulin. That could explain other results showing that drinking coffee may help protect against type-2 diabetes. Researchers focused on a chlorogenic acid naturally found in coffee, demonstrating in the lab significant inhibitory effects on the compounds linked to pancreatic cell death.
Then in March, an analysis of nine years of data on 42,659 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) study concluded that coffee wont hurt your heart or give you cancer, and it might even reduce your risk of diabetes. Publishing their findings in the American Journal of Clinical Nutrition, German researchers found no connection between coffee consumption and increased risk of heart disease or cancer. But participants who drank four or more cups of coffee daily were 23%-30% less likely to develop type-2 diabetes than those drinking less than a cup per day.
The apparent protective benefit of coffee-which echoes that seen in a 2009 meta-analysis-could be due to the presence of magnesium, antioxidant lignans or chlorogenic acids, scientists speculated. Its not caffeine, however, as decaf drinkers actually saw an even lower risk of diabetes. The bottom line, as an accompanying editorial put it, is that current information suggests that coffee is not as bad as we were told.
If all this tempts you to pour yourself a celebratory cup of coffee, keep in mind that the beverage is not without its potential downsides. Some studies have found that compounds in unfiltered coffee, such as from a percolator or French press, can raise unhealthy LDL cholesterol. Oils called terpenes are thought to be to blame; filtering coffee, such as in a drip coffee maker, removes most of the terpenes.
Of course, if you like your coffee in the form of fancy coffeehouse drinks laced with sugar and full-fat dairy, those additions will likely more than cancel out any modest health benefits from the coffee.
But if youve just brewed a fresh, filtered pot of black coffee, go ahead and indulge in that not-so-guilty pleasure. Science says it wont hurt you-and might even help you live longer.
TO LEARN MORE: New England Journal of Medicine, May 17, 2012; abstract at www.nejm.org/doi/full/10.1056/NEJMoa1112010. Journal of Agricultural and Food Chemistry, Dec. 28, 2011; abstract at dx.doi.org/10.1021/jf201702h. American Journal of Clinical Nutrition, April 2012; abstract at www.ajcn.org/content/95/4/901.abstract.