A recent study suggesting a link between coffee drinking and longer lives has prompted a flurry of coverage—some snarky, some cautious, but mostly celebratory. (We see you there, reaching for another cup of coffee.)
The study published at the prestigious New England Journal of Medicine is about as good as observational epidemiology studies go, but it’s limited by virtue of being observational. Last month on our Crux blog, Gary Taubes wrote a hard-hitting piece about the problems with observational studies. A major limitation of surveying people about their lifestyle habits is that correlation does not imply causation. It can’t prove coffee drinking actually led to living longer. There are always confounding variables. Read More
Ripening coffee berries.
Coffee aficionados may look down their noses at decaf beans, which are chemically treated to rob them of their caffeine, and, some say, their flavor. But the market for decaf is worth $2 billion a year, and if scientists can create a bean that’s naturally stimulant-free, well…that would be a kick. A new feature at Nature News chronicles the frantic efforts of plant biotechnologists to create such a caffeine-free coffee bean. It’s a tall order:
Developing such a bean through conventional breeding or even genetic modification has proved more difficult than anyone anticipated. Coffee plants take years to begin producing beans, and can be fickle when they do. Moreover, to make them profitable to farm, the plants need to be productive, ripen synchronously and be of a size and shape that can be harvested easily by hand or by machines. The loss of any of these traits can render a plant worthless.
A couple cups of coffee a day may help keep the blues away. A large epidemiological study of 50,000 women published yesterday in the Archives of Internal Medicine found that subjects who drink two or more cups of coffee on a daily basis were slightly less likely to be diagnosed with depression over a 10-year span compared to their less-caffeinated peers. Women who drank two to three cups of coffee were 15 percent less likely to be treated for the blues; those who drank four or more had a 20 percent lower risk.
Those dark rings in the bottom of your cup arise from fundamental physics.
What’s the News: Some of the most mundane things in life—drinking through a straw, for instance, or washing your hands with soap—are the results of some really neat physics. Today, scientists are adding another item to that list: The ring that forms around a drying drop of coffee. A team at University of Pennsylvania has discovered that that brown ring is a result of the shape of the particles floating in your coffee—and if you squash them out a little, the coffee ring disappears.
Go ahead, order that latte with a double shot of espresso. Then do it again and again. A new study shows that drinking up to six cups of coffee a day won’t shorten your life span, and for women that daily coffee habit may even protect against heart disease.
The Spanish researchers who conducted the study are excited about their findings, but they stop short of prescribing coffee jolts to all. “Our results suggest that long-term, regular coffee consumption does not increase the risk of death and probably has several beneficial effects on health,” said lead researcher Dr. Esther Lopez-Garcia…. Lopez-Garcia stressed that the findings may only hold true only for healthy folk. “People with any disease or condition should ask their doctor about their risk, because caffeine still has an acute effect on short-term increase of blood pressure,” she said [HealthDay News].