Red Alert : Energy drinks put kids, young adults at risk - report

CHICAGO (Reuters) - Energy drinks -- which contain high levels of caffeine and other stimulants -- may put some children and young adults at risk for serious health problems and should be regulated, U.S. researchers said on Monday.

They reviewed scores of scientific studies on the health effects of energy drinks, including brands like Red Bull, Spike Shooter and Redline, and found cases of seizures, delusions, heart problems, and kidney or liver damage.

"Across the world, there are signs that for some people who consume these drinks, there are side effects," said Dr. Steven Lipshultz of the University of Miami, whose study appears in the journal Pediatrics.

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

Lipshultz's team is especially concerned about the effects on young adults and children, which account for half of the projected $9 billion in U.S. sales of nonalcoholic energy drinks. The report calls for regulatory action and more research.

Coca-Cola Co, PepsiCo Inc and other soft drink companies have their own energy drinks. The fast-growing market is dominated by brands like Red Bull, Rockstar and Hansen Natural's Monster.

The report comes just months after a U.S. crackdown on alcoholic caffeinated beverages such as Phusion Projects' Four Loko.

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

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

Because the beverages are classified as nutritional supplements, the U.S. Food and Drug Administration does not require their manufacturers to prove they are safe or effective.

To get a handle on the problem, Lipshultz and colleagues systematically searched studies and manufacturer websites for product information on energy drinks, which they defined as "beverages that contain caffeine, taurine, vitamins, herbal supplements and sugar or sweeteners and are marketed to improve energy, weight loss, stamina, athletic performance and concentration."

They found the drinks have been linked with "serious adverse effects, especially in children, adolescents, and young adults with seizures, diabetes, cardiac abnormalities, or mood and behavioral disorders or those who take certain medications."

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

Caffeine is a particular worry, according to the team.

Of the more than 5,000 U.S. caffeine overdoses reported in 2007, 46 percent occurred in youths aged 18 or younger.

According to one study from New Zealand, just one energy drink is enough to make most kids experience some side effect, including mild ones like irritability or upset stomach.

High doses of the herbal extract yohimbine have been linked to increased blood pressure and heart rate. And like ginseng, yohimbine may interact with other drugs.

"If it were as simple as energy drinks just containing caffeine, that would be one thing," Lipshultz said. "The problem is they contain a lot of other substances."

Until the effects of these drinks are clear, Lipshultz says young people with heart disease, seizures, diabetes, high blood pressure, or attention-deficit hyperactivity disorder should avoid the drinks.

Manufacturers downplayed the report.

"This article just draws together material from the Internet and largely ignores in its conclusions the genuine, scientifically rigorous examination of energy drinks by reputable national authorities," Red Bull said in an emailed statement.

The American Beverage Association said most mainstream energy drinks contain half the caffeine of a similar-sized cup of coffee.

Coke and Pepsi referred calls for comment to the American Beverage Association, and Hansen declined to comment.

(Reporting by Julie Steenhuysen and Frederik Joelving for Reuters Health; Additional reporting by Martinne Geller; Editing by Lisa Von Ahn)

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