How much do you really know about it?

NBC News

Dr. Bob Arnot

June 12, 2000

June 12, 2000 — It makes getting out of bed in the morning almost worthwhile. Caffeine is part of so many things we love from coffee to chocolate to soda. But is caffeine friend or foe? We’ve heard so much conflicting information, it’s hard to know. How much do you really know about caffeine? Chief Medical Correspondent Dr. Bob Arnot reports.

IT SEEMS THAT almost everyday that we hear something new about caffeine. Even the experts don’t seem to agree so it’s no wonder we’re confused about caffeine. Should we have a little or a "latte"?

Even if you’ve made up your mind to cut down on espresso, caffeinated products are hard to avoid. There’s caffeine in chocolate, in most sodas and even in some painkillers.

"Almost everyone in the United States takes in caffeine in some form or another," says Dr. Stephen Scheidt, director of the cardiology training program at New York Hospital. For several years he has studied and lectured on the effects of caffeine on the entire body. We asked him to give us the scoop on caffeine.

For starters, which has more caffeine: tea or coffee? Dr. Scheidt says the answer is clear. "Coffee has more caffeine than tea," he says. "Coffee as brewed in the united states has about 100 to 130 milligrams of caffeine per cup. Tea usually has about 40 or 50 milligrams of caffeine."

If you are a tea drinker, Dr. Scheidt says you should know the darker the tea, the more caffeine it will likely have.

So what kind of effect will caffeine have on your body? Can it give you high blood pressure? Dr. Scheidt says that caffeine can temporarily increase your blood pressure — perhaps for minutes or even hours. But "the key question is: Is caffeine associated with a development or the worsening of high blood pressure that 60 million Americans have?" asks Dr. Scheidt. "And that’s myth."

So if caffeine won’t give you high blood pressure, could it give you a heart condition? Dr. Scheidt says there’s no question. "Mainly myth," he says. "Caffeine certainly cannot give you a heart condition. Inconceiveable, has never even been suggested."

But if you do have a heart problem, Dr. Scheidt says caffeine might make your heart race. But it’s highly unlikely to worsen your heart condition.

Another concern people have about caffeine and cancer? Is there a link between caffeine and cancer?

Dr. Scheidt says this has been studied exhaustively. "It’s been looked at very, very seriously," he says. "There is no association with cancer."

But should certain people avoid caffeine? Should pregnant women avoid caffeine?

And the doctor’s orders? "I think that to be prudent, someone who’s pregnant should reduce caffeine consumption and should probably drink fewer than three cups of coffee a day," says Dr. Scheidt.

So expectant moms shouldn’t have to give up caffeine altogether. But what if a woman is trying to get pregnant. Will caffeine affect her fertility?

Scheidt says, "There are some studies that show that large doses of caffeine — that would be three to five to seven cups of coffee a day — can delay fertility. That means you get preganant a couple of months later than you otherwise would have gotten pregnant."

Here are some other things to remember about caffeine: It’s a performance enhancer. It can make you more alert. And it’s also a pain killer, which is why you often find it in medications.

But be careful. Caffeine can also increase your anxiety levels and keep you awake at night, because it’s a stimulant.

So just how much caffeine can the average person safely consume on a daily basis? Dr. Scheidt says that the caffeine content of six cups of coffee, six cans of soda or even 60 chocolate bars won’t harm you—that is unless you have a sensitivity to caffeine such as getting an upset stomach or even a case of the jitters.

And remember, caffeine is a drug and shouldn’t be abused. Dr. Scheidt says moderation is the key.

"I think caffeine has gotten a very bad rep and I wouldn’t worry about ordinary drip coffee," he says. "It’s a pleasure in life and there’s no evidence that it’s really bad for you. My suggestion is — have a latte."