“The caffeine content of energy drinks varies over a ten-fold range, with some containing the equivalent of 14 cans of Cola drinks, yet the caffeine amounts are often unlabelled and few include warnings about the potential health risks of caffeine intoxication,” says Roland Griffiths, one of the authors of the article.
Without adequate, prominent labelling, consumers most likely will not realise whether they are getting a little or a lot of caffeine. “It is like drinking a serving of an alcoholic beverage and not knowing if its beer or scotch,” says Griffiths.
A regular twelve-ounce cola drink has about 35 milligrams of caffeine, and a six-ounce cup of brewed coffee has 80 to 150 milligrams of caffeine. 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 (71 milligrams per twelve-ounce can) does not apply. The caffeine content of energy drinks varies from 50 to more than 500 milligrams, the authors write.
Caffeine intoxication, a recognised clinical syndrome included in the Diagnostic and Statistical Manual of Mental Disorders and the World Health Organization’s International Classification of Diseases, is marked by nervousness, anxiety, restlessness, insomnia, gastrointestinal upset, tremors, rapid heartbeats (tachycardia), psychomotor agitation (restlessness and pacing) and in rare cases, death.
Reports to U.S. poison control centers of caffeine abuse showed bad reactions to the energy drinks. In a 2007 survey of 496 college students, 51 percent reported consuming at least one energy drink during the last month. Of these energy drink users, 29 percent reported “weekly jolt and crash episodes”, and 19 percent reported heart palpitations from drinking energy drinks. This same survey revealed that 27 percent of the students surveyed said they mixed energy drinks and alcohol at least once in the past month. “Alcohol adds another level of danger,” says Griffiths, “because caffeine in high doses can give users a false sense of alertness that provides incentive to drive a car or in other ways put themselves in danger.”
MEDICA.de; Source: Johns Hopkins Medicine