Energy drinks pack a punch, but is it too much?

Energy drinks typically contain as much caffeine as a cup of coffee

By Elizabeth Cohen
CNN Medical Unit

ATLANTA, Georgia (CNN) -- Tracie Rosado is managing partner of The Martini Club in Atlanta, where "energy drinks" are best sellers -- and she knows why. "If I'm tired I just grab a can and I'm good to go," she said. "It just makes me feel alert, awake."

Energy drinks -- there are many, with names like Red Bull, Adrenaline Rush, and 180 --- are a big hit at bars, dance clubs, and even Wal-Mart. They contain vitamins, amino acids, and about as much caffeine as a cup of coffee.

"These cans of energy drinks have some enticing, very sexy-sounding claims -- that they lift you up, that they give you more energy," said Liz Applegate, a sports nutritionist at the University of California at Davis, who's studied the drinks. "Frankly, they're nothing much more than caffeine in a can with a lot of sugar."

Kim Peterson, a spokeswoman for Red Bull, a popular energy drink, said the beverage is uplifting because it contains vitamins and amino acids, such as taurine. On its Web site, the company says taurine "acts as a metabolic transmitter and additionally has a detoxifying effect and strengthens cardiac contractility." However, its effects are disputed in the scientific community.

Applegate maintains the boost comes mainly from caffeine. And that, she says makes energy drinks a bad idea for athletes.

"Even though they're labelled 'energy drinks', they should not be consumed during exercise. They have caffeine, and they're too concentrated in sugar. That's going to slow the body's ability to absorb water," she said.

In a statement, Peterson said the beverage "vitalizes body and mind" but "is not a 'thirst quencher' or fluid replenishment drink."

The Red Bull Web site, however, tells a slightly different story. It recommends Red Bull as an "ideal energy drink... prior to demanding athletic activities, or in a performance drop during a game."

At the Martini Club, the patrons didn't seem to care much about athletic performance. They mixed their Red Bull with vodka, sometimes downing one drink after another. This worries some cardiologists, who say large amounts of either caffeine or alcohol could be dangerous to the heart.

"If they were to drink multiple glasses of this mixture or concoction, I think there'd be a potential for significant danger -- danger such as a racing heart beat, elevation of blood pressure and even potentially a heart attack," said Dr. Laurence Sperling, a cardiologist at the Emory University School of Medicine.

Peterson said in a statement that "Red Bull does not actively market itself as a mixer for alcohol drinks."

But on question-and-answer page on its Web site, the company says it's okay to mix the drink with alcohol.

"Can you mix Red Bull with alcohol? Yes!" according to the Web site, which states that a "medical report by the 'Institute for Legal Medicine' of the University of Munich" confirms that Red Bull has no effect on the alcohol metabolism."

Applegate, the sports nutritionist, said she's concerned that people who ingest a lot of caffeine, a stimulant, along with a lot of alcohol, which has a tranquilizing effect, won't realize how drunk they really are.

"I'm concerned that they may drink more than they would have without the caffeine, because of that alert feeling, and perhaps go out and drive a car," she said.

Still, Applegate said energy drinks aren't necessarily unhealthy as long as they're consumed in moderation and without alcohol.

And while they might be energizing, she added, they're no more so than anything else with the same amount of caffeine.