According to the National Coffee Association, the majority of Americans (60 percent) drink coffee on a daily basis, consuming on average just over three cups a day. But according to a new study, those under 55 who drink four cups daily (or 28 per week) or more are at greater risk of dying early. However, once you get past that headline, it doesn t really seem that there s much to worry about. And in recent years, it s even been found that drinking coffee is associated with a reduced risk of cancer, heart failure and other conditions.
Researchers followed over 44,000 people ages 20 to 87 for 16 years. They recorded about 2500 deaths over that time period. After adjusting for smoking, fitness and other factors, they reported that people who drank over 28 cups of coffee each week were at a 21 percent increased risk of all-cause mortality. That risk was even higher about double for those under 55.
However, despite the scary headlines to some extent encouraged by the author and his locus, the Ochsner Clinic this study cannot say anything about cause and effect. This study was purely observational, collecting data without intervening in the subjects behaviors in any way. The only way to prove a connection would be to organize a study in which individuals would be assigned to two different groups: one in which participants drink large amounts of coffee, and the other in which they don t, and then are followed for years while outcomes are assessed. Furthermore, while the authors asserted that they controlled for various factors other than coffee (such as smoking, obesity, diet, family history, etc) that can impact mortality, in reality it s very hard to control for all such factors, as Rachel Huxley, chair of epidemiology at the University of Queensland in Australia points out. And Rob van Dam, associate professor at the National University of Singapore, says that there are other shortcomings such as the fact that study authors did not look at dietary habits or specific causes of death.
ACSH s Dr. Gilbert Ross adds, Coffee is a particularly fraught subject for medical studies; whatever is seemingly revealed always generates big headlines and viewers for the TV news. This one is no exception, obviously. Yet there is not much at the study s core to truly concern anyone, neither coffee drinkers nor those who love them. There is just no biological explanation for why or how a lot of coffee might increase lethal diseases, excluding heart disease, which the authors specifically evaluated and found to not contribute to the excess deaths observed. And numerous prior studies have failed to reliably link coffee consumption to significant health outcomes, either beneficial or adverse. These folks have brewed up a mess of alarm, but I d suggest that folks chill out with a nice, cool macchiato, extra shot please.