Have you wondered how many people consume energy drinks on a daily basis, or even more often? Or what happens if you combine them with alcohol? Well, we must tell you there isn’t good news; and warn you to be careful.

At first, these high-caffeine drinks were consumed by all gaming elite to ensure their speed is high and reflexes are sharp in extended play, because the drinks were promoted as performance enhancers. However, they soon gained popularity so that an incredible number of people, not only gamers, consume them. It seems that United States citizens alone spent approximately 5.4 billion U.S. dollars on energy drinks in 2006, a figure growing about 47 percent per year, a report said.

According to the findings of a new study published in the Sept. 20 issue of the journal Drug and Alcohol Dependence, the super-caffeinated energy drinks can trigger caffeine intoxication. "The caffeine content of energy drinks varies over a 10-fold range, with some containing the equivalent of 14 cans of Coca-Cola, yet the caffeine amounts are unlabeled and few include warnings about potential health risks of caffeine intoxication," said one of the authors of the study, Roland Griffiths of Johns Hopkins University School of Medicine in Baltimore, Maryland.

Caffeine intoxication is clinically considered a syndrome. It is currently defined by a number of symptoms and clinical features that surface in response to recent excessive consumption of caffeine. Common features of caffeine intoxication include excitement, anxiety, rapid heartbeat, restlessness, tremors, insomnia, rambling flow of thought and speech or periods of inexhaustibility. In rare cases, caffeine intoxication can lead to death.

One death apparently linked to the intake of a popular energy drink, Red Bull, made the headlines in 2000, when Irish athlete Ross Cooney, 18, died of sudden adult death syndrome hours after drinking four cans of the drink. Following the occurrence, France prohibited the energy drink, but it removed the ban only days after. However, in countries such as Norway, Uruguay and Denmark, it remains banned.

Since a lot of energy drinks are marketed as "dietary supplements" that increase energy and physical performance, the limit the FDA requires on the caffeine amount found in energy drinks isn’t valid. Caffeinated energy drinks are a growing concern because they guarantee super alertness. Still, they carry with 10 times or even more the caffeine content of soft drinks.

The team of researchers from Johns Hopkins University who carried out the study said that manufacturers should note on caffeinated energy drinks’ labels the caffeine doses the products carry, and to caution on presumptive risks they pose to consumers.

The caffeine content of energy drinks can vary from can to can, from 50 milligrams to more than 500 milligrams per serving, whereas a normal 12-ounce cola drink has approximately 35 mg of caffeine per serving and a 6-ounce cup of brewed coffee has 80 to 150 milligrams of the stimulant drug per serving.

On the word of one drink-company manufacturer, the energy drinks can be a harmless substitute to drug abuse for youngsters. “We say, ‘Do the drink, not the drug,''' stated Raymond Herrera, Partner and world wide marketing director of Redux Beverages. “You do the drug you are dumb. If you do the drink you are cool.''

The Johns Hopkins researchers also said that caffeinated drinks can cause abuse of prescription stimulant drugs like Ritalin.