Tired, wired and young

Meet Jamey Kirby. If you're young enough, and hip enough, he'd like to sell you some Cocaine.

Arriving soon at a convenience stores in the US, Cocaine is a recent and controversial entry in the burgeoning market for so-called energy drinks. Loaded with caffeine and sugar, and often laced with herbs, vitamins or amino acids, they have become the fuel of choice for some thrill-seeking youngsters and, more recently, for weary adults navigating an always-on world.

But with their increasingly novel additives, energy drinks are taking consumers into uncharted nutritional territory, especially because they are often used as mixers with alcohol. Even if they are not dangerous, experts say, energy drinks may be fostering an unhealthy dependence on caffeine even as they pad the waistlines of young adults.

None of that much concerns Kirby, the California entrepreneur behind Cocaine. His business is buzz — in every sense of the word. Each 8.4-ounce (approx. 250ml) can of Cocaine contains 280 milligrams of caffeine, more than twice the amount in a cup of coffee, and a throat-numbing blend of fiery spices. It's perfect, Kirby said, for jaded 16- to 28-year-olds clamoring for extreme refreshment.

And the provocative name? Just marketing. "It was always the plan to let negative publicity move us forward," Kirby said. "There is an enormous amount of competition out there."

About that, there is no controversy. Nearly 200 new energy drinks have hit store shelves since January, according to the market research firm ACNielsen. Led by such brands as Red Bull, Rockstar and Monster, energy drinks are a US$3.7 billion industry whose revenues have increased by 51 percent in the past year alone. Red Bull is the third-largest source of beverage profits in US convenience stores, according to one recent market survey.

"It started out as something for clubbers and extreme-sports types," said Jeffrey Klineman, the editor of Beverage Spectrum. "Now it's gone mainstream."

So has the ingredient list. Energy drinks increasingly are formulated with fruit juices, teas and dietary supplements like ginseng and glucosamine that appeal to older, health-minded consumers. Taurine, an amino acid essential to growth in infants, is a frequent additive, though scientists say large amounts provide no advantage to ordinary adults.

Despite exotic formulations, the energy boost in these drinks is delivered via a whopping dose of common caffeine.

This year, in a study published in the Journal of Analytical Toxicology, a team of researchers analyzed the caffeine content of 10 popular energy drinks and found concentrations as high as 141 milligrams per 16-ounce (approx. 500ml) can. While the Food and Drug Administration does not regulate the amount of caffeine in soft drinks, agency guidelines for colas suggest no more than 68 milligrams per 12-ounce (approx. 355ml) serving.

Only four of the drinks carried caffeine warnings on their containers, the researchers noted, and none suggested a limit.

"The caffeine content really should be listed on the labels," said the lead author, Bruce Goldberger, a toxicologist at the University of Florida. "Caffeine may be the mostly widely used drug in the world, but certain people need to avoid it."

Among them are those with high blood pressure, cardiovascular disease and certain anxiety disorders, as well as pregnant women.