MADELEINE BRAND, host:
From NPR News, this is DAY TO DAY.
We know that coffee is addictive, pleasurable, and if you run Starbucks, extremely profitable. But, good for you? Several recent studies suggest that yes, coffee is surprisingly healthful. Dr. Sydney Spiesel sifted through those studies and he joins us now from his pediatrics office in Woodbridge, Connecticut. Hi, Syd.
Dr. SYDNEY SPIESEL (Yale Medical School): Hi. How are you?
BRAND: Fine, thank you. So let's begin with the bad news first. Coffee does have some detrimental affects, doesn't it?
Dr. SPIESEL: It does have some detrimental affects. For some - for many people it interferes with sleep. It will sometimes cause your heart rate to go up. Some people find that their stools get loose. If people drink enormously large doses, they can have seizures and supposedly, it can even lead to death. Now, I had always believed that Voltaire, who was a tremendous coffee drinker, died after drinking 40 cups, but it turned out not to be true.
BRAND: He didn't die from it?
Dr. SPIESEL: No.
BRAND: So that leads us to the next question, that it's not as bad as we thought it was. And let's talk about the antioxidants. Coffee, we find from these studies, has them. Has a lot of them.
Dr. SPIESEL: Yeah. I was surprised myself to learn that. That coffee has more antioxidants than the foods that are traditionally thought of as rich in antioxidants. Things like green tea and red wine. That's the good news. The bad news is we're not exactly sure. We think that these are good for us, but we're not exactly sure they are.
BRAND: Another surprising finding in one of these studies is that coffee may be associated with a lower risk of type two, or that is, adult onset diabetes. And what are the details there?
Dr. SPIESEL: Well, this is really amazing. There have been at least seven quite good studies done in multiple places. It turned out that there was a strong association between drinking coffee and a decrease in the risk of developing type two diabetes. And the more coffee you drink - and I'm not suggesting that people drink quarts - but the more coffee you drink, the greater the protection seems to be.
BRAND: Well, I wonder if there might be other reasons. Such as people who drink a lot of coffee may not be drinking a lot of, let's say, sugary sodas, or…
Dr. SPIESEL: Well, I think there might be other things, this hasn't been studied. But on the other hand, this goes across to many different cultures. First of all, there was a study done at the University of Minnesota under the direction of Mark Pereira, in which they actually looked at 28,000 post-menopausal women over 11 years. And they did find that the coffee was protective, but, in fact, it had nothing to do with caffeine. Decaffeinated coffee actually seemed to work better in that study than caffeinated coffee.
Another study that thrilled and amazed me had to do with Finland. A guy named Jaakko Tuomilehto of the Finnish National Public Health Institute in Helsinki studied 14,000 men and women over 14 years. And for every person in Finland - every man, woman, child, infant - they used 25 pounds of coffee a year, which works out to about two and three-quarters cups a day for everybody.
BRAND: That's an alert country, right there.
Dr. SPIESEL: That's an alert country. Sixteen percent of this study - 14,000 people - drink 10 or more cups a day.
Dr. SPIESEL: And they found that the people who drank the most in that study had the most benefit at decreased risk of developing diabetes.
BRAND: So how many cups do you drink, Syd?
Dr. SPIESEL: I probably drink, I don't know, four to six cups of coffee a day. My wife and I sometimes drink a cup just before bed.
BRAND: Just before bed? And you sleep like a baby?
Dr. SPIESEL: Yeah.
(Soundbite of laughter)
Dr. SPIESEL: I sleep better than many of the babies I deal with, it turns out.
BRAND: That's opinion and analysis from Dr. Sydney Spiesel. He's a pediatrician and a professor at the Yale Medical School. He writes the Medical Examiner column for the online magazine Slate. Thank you, Syd.
Dr. SPIESEL: Thank you.
BRAND: More coming up on DAY TO DAY from NPR News.