As Sales Soar, Experts Warn About Energy Drinks

With Americans chugging energy drinks like never before, fears are growing among doctors that the ingredients might be putting some consumers at risk.

The beverages contain a hodgepodge of caffeine, sugar and dietary supplements such as vitamins and herbal extracts, whose effects aren't well understood.

In a new report out Monday, Florida pediatricians describe cases of seizures, delusions, heart problems and kidney or liver damage in people who had downed one or more non-alcoholic energy drinks -- including brands like Red Bull, Spike Shooter and Redline.

"Across the world there are signs that for some people who consume these drinks, there are side effects," said Dr. Steven E. Lipshultz, who heads the department of pediatrics at the University of Miami Leonard M. Miller School of Medicine.

"The incidence is low, but in certain groups that pediatricians care for there may be higher risks," he added.

The report, which calls for regulatory action and more research, comes only months after a U.S. crackdown on alcoholic caffeinated beverages such as Phusion Projects' Four Loko.

U.S. sales of non-alcoholic energy drinks are expected to hit $9 billion this year, with children and young adults accounting for half the market.

Because the beverages are classified as nutritional supplements, they have received much less scrutiny and are under fewer restrictions than both foods and drugs.

Manufacturers claim their products will enhance both mental and physical performance. Red Bull's website, for instance, says energy drink will increase concentration and reaction speed, and improve vigilance and emotional status.

"Red Bull's effects are appreciated throughout the world by top athletes, busy professionals, active students and drivers on long journeys," the website claims.

In 2010 alone, the company told Reuters Health, it sold in excess of 4 billion cans and bottles of the drink, which is now available in more than160 countries.

But according to the Florida researchers, who reviewed the medical literature on the topic, the industry's claims of benefit are questionable.

"We couldn't find any evidence at all of any therapeutic effects," Lipshultz said.

He began to take an interest in energy drinks a few years ago, when four kids from South Florida were brought to the hospital after swallowing a vitamin concoction their teacher had bottled.

"They all came in feeling tingling all over," Lipshultz said. "This prompted me to say, we've got to really learn about this."