A new study in U.S. has called that energy beverages should carry labels listing the content and warn about health risks, according to media reports Friday.

Because many energy drinks are marketed as "dietary supplements," the limit that the Food and Drug Administration requires on the caffeine content of soft drinks does not apply. Caffeinated energy drinks that promise super alertness carry with 10 times or even more the caffeine of soft drinks.

"The caffeine content of energy drinks varies, yet the amounts are often unlabelled and few include warnings about the potential health risks,” said study author Roland Griffiths, a professor of behavioral biology at Johns Hopkins University School of Medicine, Baltimore, Maryland.

Caffeine intoxication can lead to nervousness, anxiety, restlessness, insomnia, gastrointestinal upset, tremors, rapid heartbeat and overdose.

"If you are going to use a drug, you should know what it is, what it does and how to use it effectively," said Griffiths, "If you don't label that, you don't know that."

"It's like drinking a serving of an alcoholic beverage and not knowing if its beer or scotch," Griffiths added.

Americans spent about US$5.4 billion on energy drinks in 2006, an amount growing about 47 percent a year, according to the report. The drinks are promoted as performance enhancers and aimed at young people.

(Agencies via Xinhua September 26, 2008)