Garlic Supplement

Caffeine buzz can take a toll on your health

By Kelly James-Enger | Special to the Tribune

March 2, 2008

Hooked on your morning venti latte? You're not alone. A recent study named Chicago as the "most caffeinated" city among 20 major U.S. metropolitan areas. Whether your pick-me-up of choice is coffee, soda or an energy drink like Red Bull, you probably haven't considered the possibility of taking in too much caffeine. Yet health experts now warn that too much of this ubiquitous stimulant can be dangerous.

Dr. Danielle McCarthy, a medical resident in emergency medicine at Northwestern University, presented a study a little more than a year ago that examined the number of calls concerning caffeine overdose to the Illinois Poison Center in Chicago. The center receives about 90,000 calls annually, and during the course of three years, 265 calls met the criteria for caffeine abuse, 12 percent of whom were hospitalized. Although these cases involved people who had ingested caffeine medications and dietary supplements, not coffee or tea, abusing caffeine can have health consequences.

"I think the most important thing is [that] caffeine is a drug, and that any drug taken in excess can act on the body like a poison," McCarthy said. "Laypeople and a lot of physicians think of it as a food product, and therefore don't consider it dangerous."

"In low doses, caffeine certainly does wake you up and makes you more alert -- it even has a bit of a euphoric effect," said Dr. Timothy Erickson, an attending physician and professor of emergency medicine and toxicology at University of Illinois. It improves cognitive function, and some studies suggest that it may enhance athletic performance as well.

But excessive doses can cause rapid heard rate, jitteriness and elevated blood pressure, which can lead to seizures and cardiac problems. Even young, healthy people have died from caffeine overdose, although it's usually intentional, such as taking a large amount of caffeine pills.

The survey on caffeine consumption was conducted by Prince Market Research and included coffee, tea, chocolate, sodas, energy drinks and caffeine pills in 20 U.S. cities. After Chicago, the next four were Tampa, Miami, Phoenix and Atlanta.

So how much caffeine is in your favorite beverage? An average brewed cup of coffee contains about 100 milligrams of caffeine, but other coffee drinks like lattes and espressos can contain double or triple that amount. Eight ounces of Red Bull energy drink contains 76 milligrams of caffeine, while No Name energy drink contains 280 milligrams.

Mega-doses of thousands of milligrams of caffeine are clearly life-threatening, but there's no clear standard for how much caffeine is dangerous. People develop tolerance over time; in other words, the more caffeine you consume regularly, the less of an impact it may have. And energy drinks also can pack more of a wallop than people realize as they often contain guarana, a South American plant that also contains caffeine and basically doubles the caffeine-like effects of the drink, Erickson said.

The practice of mixing energy drinks with alcohol or other drugs can also be dangerous, he warned. "They really ramp you up, and people mix or match [them] with alcohol or whatever else is circulating at the party," Erickson said. "People think caffeine is going to ride them through [the effects of] alcohol or some of the other drugs they take, but many of these drugs can overpower the effects of what we're used to seeing with caffeine."

Combining energy drinks with other powerful stimulants, such as caffeine or methamphetamine, can heighten the drugs' effect.

Even everyday caffeine consumption can dehydrate you, cause stomach problems or cause headaches from withdrawal when you don't consume your usual amount. If you rely on caffeine to keep you going, you may be setting yourself up for a problem later.

"These are high-functioning, well-educated, energetic, really productive people who are just trying to get that added edge, and there's nothing wrong with that," Erickson said. "But what you get into is you need a lot of caffeine to get going in the morning, and then you need a little wine or alcohol to get back down at night -- and pretty soon it comes back to bite you."