Leaving his ambulance idling outside, yellow lights flashing, Denver paramedic Austin Coleman strides into a 7-Eleven just south of University Hospital and heads straight for the beverage cooler.
He jerks open a door, reaches in and hauls out his favorite pick-me-up – a 16-ounce can of the energy drink Rockstar, which he typically buys at the beginning of every 10-hour work shift.
“It makes me awake,” the 30-year-old rescue worker says of the concoction, one of dozens of caffeine-laced brands now bellying up to a bar once occupied solely by Red Bull.
“I’ve tried them all, and they work, that’s for sure,” Coleman says. “This one has more than the regular size, and I like the sugar-free kind.”
Like its competitors, Rockstar promises a metabolic jump-start. As the legend on the side of the can puts it, “Rockstar is scientifically formulated to provide an incredible energy boost for those who lead active and exhausting lifestyles – from athletes to rock stars.”
But it’s an open question whether this or any other “high-performance” beverage actually conveys much more benefit than, say, a cup of coffee and a banana or peanut-butter sandwich. As the small type on virtually every brand reads, “These statements have not been evaluated by the Food and Drug Adminstration.”
Moreover, another aspect of energy drinks – their widespread use as a mixer in cocktails, most commonly Red Bull and vodka – is raising fears of an increase in alcohol abuse and drunken driving.
“Because the caffeine masks the effects of the alcohol, you don’t realize how intoxicated you are, so you think it’s OK to drive,” explains Jim Mosher of the Pacific Institute for Research and Evaluation, a California-based center providing guidance to a federal task force on college-age drinking.
The risks of mixing alcohol with energy drinks, he adds, may be heightened by the latest twist on such products – energy drinks already infused with alcohol, such as Anheuser-Busch’s Tilt or Miller’s Sparks.
Perhaps the most worrisome of these so-called “malternatives,” in Mosher’s view, is Rockstar21, which contains 6 percent alcohol and comes in a can “that looks identical to the non-alcohol version” – meaning it might be consumed inadvertently by non-drinkers. Or, more probably, consumed on purpose by underage teens.
“We’re talking 13- and 14-year-olds, particularly girls, who don’t like the taste of beer,” he says. “These drinks are the new wine coolers, like the ‘alcopops’ that were big in 2001 – Smirnoff Ice, Mike’s Hard Cider, Bacardi Breezer. They’re alcoholic, like beer, but they taste and look like pop, and they have this added effect of caffeine. I don’t know how much of the market these kinds of drinks represent, but I’m expecting they’re going to explode.”
Caffeinated beverages, researchers have found, do have some positive effects on athletic performance. Numerous studies show that at doses up to 200 milligrams (the quantity in about two cups of brewed coffee, or 2 1/2 cans of Red Bull), such drinks can increase vigor and stave off exhaustion during prolonged, strenuous exercise such as an extended bike ride or mountain climb.
But the benefits “diminish somewhere between 500 and 900 mg, taken in a single dose,” says physiologist Lawrence Armstrong, an exercise researcher at the University of Connecticut.
In addition, as many users might attest, such high levels of caffeine can lead to headaches, anxiety, indigestion, heart palpitations or insomnia – especially in people who don’t ordinarily ingest the stuff.
And at high elevations, there is evidence that caffeine may reduce the blood flow to the heart.
“If you’re looking for a competitive edge in an event, you would want to test it out and know your tolerance for caffeine beforehand. It could upset your stomach and cause cramps,” says Denver dietitian Suzanne Farrell, a spokeswoman for the American Dietetic Association.
“Caffeine is a particular concern with pregnant women, children and teenagers, because everyone has a different tolerance for it,” she notes. “The question is, are they drinking only one can, or multiple cans throughout the day? How does it affect their sleep patterns, their ability to concentrate, or other aspects of their life?”
As for the other ingredients typically found in energy drinks – such as the amino acid taurine, the herbal stimulant guarana and extracts of the plants ginseng and yerba mate – the jury is still out.
“There is scant scientific support for these ingredients to make the kind of claims manufacturers use in hyping their products,” says Farrell. “Most of the energy from these drinks comes from the sugar and caffeine, not from the unnecessary extras.”
Also, says Mosher, “It’s unclear what effect, if any, these ingredients have on the body, and what interactive effect they may have when combined with alcohol.”
The biggest concern that health experts have about energy drinks involves over- consumption of caffeine – by young adults who may believe that slamming down four or five in a day is somehow “healthier” than drinking the same number of cans of soda-pop, or by partiers who may consume several with alcohol over the course of an evening.
In one recent study, a Chicago poison center reported handling 250 cases of caffeine-related medical complications over a three-year period, with 30 ending in hospitalization.
In this region, the Rocky Mountain Poison and Drug Center fielded 14 calls involving Red Bull – half of them in combination with alcohol – in the last year, reports clinical toxicologist Shireen Banerji.
“Nausea with vomiting is the biggest symptom,” she says. “It can last up to 10 hours. It’s really irritating to the system.”
As potent as Red Bull may be, it contains only about as much caffeine per can as a cup of brewed coffee. And it seems pale indeed compared to VPX Redline, a more concentrated drink that has drawn attention from poison-control officials in California. Marketed to body-builders as a fat burner and used by some truckers as a sleep preventive, Redline contains a reported 250 mg of caffeine per 8-ounce can, or three times as much as Red Bull.
“I drank one Redline and felt terrible – I was shaking, I had hot flashes, I thought I was going to throw up,” says Denver blogger Dan Mayer, a 25-year-old software engineer who samples and reviews energy drinks as a hobby.
“I drank it at lunch and couldn’t sleep the whole night and stayed up all the next day. This is not an energy drink. It’s a drug, and it’s scary.”
Most energy drinks, fortunately, carry less risk of an overdose. “A lot of adults start every day with two cups of coffee,” Mayer observes. “They probably shouldn’t worry if their kid drinks one energy drink a day, as long as it’s not consumed at 10 o’clock at night.”
Staff writer Jack Cox can be reached at 303-954-1785 or jcox@denverpost.com.
