Before I sat down to write this column, I zipped into the Dunkin’ Donuts drive-through to get a cup of iced black coffee, my favorite fuel.

I’ve been drinking coffee since I was a toddler, when my folks would allow me to add milk and sugar to the dregs in their yellow plastic mugs and sip it down. Drinking coffee in college made me feel sophisticated; pots of strong brew kept me awake through the writing of my master’s thesis and hundreds of other documents.

But much as I love — and apparently need — the stuff, I’ve had to cut back lately because too much of this good thing aggravates my acid reflux. That, along with indigestion in general, turns out to be one of the few negative side effects clearly associated with coffee.

Science has come a long way since a 1981 study in the New England Journal of Medicine found a link between coffee consumption and pancreatic cancer risk; that finding has never been replicated and is now discredited. And lately the news about coffee has been good.

Donald Hensrud, chair of preventive, occupational and aerospace medicine at the Mayo Clinic in Minnesota, says, “People have preconceptions about different foods, and the general concept about coffee is that it’s bad for you. But for most people, the benefits outweigh the risks.”

In the Checkup blog that I co-write for The Washington Post, I’ve reported on studies showing that coffee consumption might help protect against heart arrhythmia, stroke and depression in women, and basal cell carcinoma.

Alberto Ascherio, professor of epidemiology and nutrition at the Harvard School of Public Health, agrees that the news about coffee these days is generally good. But he cautions against putting much stock in single studies.

“You can find a paper suggesting that coffee is good for just about anything,” Ascherio says, “but we should be looking for consistent evidence across a broad population.”

Ascherio says that kind of strong evidence exists for coffee’s protective effect against Type 2 diabetes and Parkinson’s disease. In the former, it appears that it may be something in coffee other than its caffeine that offers protection, as decaffeinated coffee has also been found to reduce risk. With regard to Parkinson’s and many other diseases and conditions, caffeine may be the key component.

Ascherio notes that studying coffee’s health effects is tricky because coffee comes in so many forms and strengths. “It’s not the volume” of coffee consumed, “it’s the strength that we have no information on” in most population-based studies. “The amount of caffeine in coffee is extremely variable,” he says.

Beyond that, it’s increasingly clear that compounds in coffee other than caffeine have positive effects on our bodies. “There are hundreds, even thousands of components in coffee” Hensrud says, many of them antioxidants. “Among people who drink coffee, coffee is the main source of antioxidants,” he says.

Some of the potential benefits of drinking coffee, Hensrud say, include improved cognition and alertness, slight decrease in depression risk and potential reduction in risk of liver disease and even suicide risk. Concerns over cardiovascular risks have been largely set aside, he says, though some unfiltered coffee may perhaps raise “bad” LDL cholesterol.

Also, though coffee doesn’t appear to increase blood pressure over the long haul, among people who don’t drink it often, it can cause blood pressure to spike temporarily. “Tolerance seems to develop,” Hensrud explains. People metabolize caffeine differently, which accounts for why some of us can drink coffee after dinner and fall asleep soon after while others of us would lie awake all night if we sipped after supper, Hensrud says. Those differences, based to some degree on genetics, “may explain why some of us are more susceptible to coffee’s side effects and health effects,” he says.

Those side effects include insomnia, indigestion, and heart palpitations. For some, mostly men, urinary tract problems can result from drinking too much java, Hensrud explains. “And caffeine can be mildly addictive, so people who drink it all week at work might suffer weekend headaches if they don’t drink as much coffee” on Saturdays and Sundays.

Of course, if you’re accustomed to adding cream and sugar to your cuppa, or if your idea of “coffee” is a venti (20-ounce) salted caramel mocha from Starbucks, your coffee habit could lead to weight gain. That Starbucks beverage, for instance, has 510 calories, 160 from fat, which probably, er, outweighs any health benefits.

Hard as it is for me to imagine, there are plenty of folks who just don’t like coffee. Should they try to cultivate a taste to take advantage of the health benefits? Probably not, Hensrud says.

“If you don’t like it, it’s not worth it.”


Portion of Americans over age 18 who drank coffee yesterday


Number of cups of coffee people identified as “coffee drinkers” drink per day

National Coffee Drinking Trends Study,
The National Coffee Association
of U.S.A. Inc., 2011