For true coffee connoisseurs, the day doesn't get started until that first cup of joe. And when the afternoon slump occurs, there's no better pick-me-up. The real news, however, is that after years of hand-wringing, scientists are admitting that coffee poses very little risk for most people, and may keep us sharp. That's no surprise to java junkies.
"If it weren't for the coffee," David Letterman once quipped, "I'd have no identifiable personality whatsoever."
That's a sentiment most coffee lovers can understand.
Health experts offered reassuring words at the 1999 annual meeting of the American Dietetic Association: Drinking up to three cups of coffee a day poses no risk. What's more, coffee appears to have some surprising benefits.
It's easy to see why researchers take coffee seriously. One cup contains about 100 milligrams of caffeine -- enough to give infrequent coffee drinkers a potent kick, says Tony Chou, MD, a cardiologist at the University of California, San Francisco, and an authority on how coffee affects our health. Half an hour after a good strong cup, a coffee drinker's resting metabolic rate -- the number of calories burned just sitting quietly -- increases by as much as 10%. Blood pressure climbs. Heart rate accelerates. Breathing speeds up.
Researchers used to worry all that commotion was harming our hearts. But regular coffee drinkers quickly develop a tolerance to caffeine, Chou says. After a week or two, they don't get so much as a wobble in their blood pressure. Habitual coffee drinkers are no more likely to suffer from hypertension than people who never pour a cup.
Even patients with irregular heartbeats, or arrhythmia, don't seem to be troubled by caffeine, according to a study published in the Annals of Internal Medicine in January 1991. Toronto scientists reviewed five studies of people with arrhythmia. Drinking up to five cups of coffee a day, they found, didn't make anyone's heart more likely to skip a beat.