Johns Hopkins scientists who have spent decades
researching the effects of caffeine report
that a slew of caffeinated energy drinks now on the market
should carry prominent labels that note
caffeine doses and warn of potential health risks for
consumers.
"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 often unlabeled, and few include
warnings about the potential health risks of caffeine
intoxication," said Roland Griffiths, one of the
authors of the article that appears in the journal Drug
and Alcohol Dependence this month.
The market for these drinks stands at an estimated
$5.4 billion in the United States and is
expanding at a rate of 55 percent annually. Advertising
campaigns, which principally target teens and
young adults, promote the performance-enhancing and
stimulant effects of energy drinks and appear
to glorify drug use.
Without adequate, prominent labeling, the researchers
said, consumers most likely won't realize
whether they are getting a little or a lot of caffeine.
"It's like drinking a serving of an alcoholic
beverage and not knowing if it's beer or scotch," Griffiths
said.
Caffeine intoxication, a recognized 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," Griffiths said, "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."
A regular 12-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 12-ounce can)
does not apply. The caffeine content of energy
drinks varies from 50 to more than 500 milligrams.
Chad Reissig, one of the study's authors, said, "It's
notable that over-the-counter caffeine-containing products
require warning labels, yet energy drinks do not."
Griffiths noted that most of the drinks advertise
their products as performance enhancers and
stimulants — a marketing strategy that may put young
people at risk for abusing even stronger
stimulants, such as the prescription drugs amphetamine and
methylphenidate (Ritalin). A 2008 study
of 1,253 college students found that energy drink
consumption significantly predicted subsequent
nonmedical prescription stimulant use, raising the concern
that energy drinks might serve as "gateway"
products to more serious drugs of abuse. Potentially
feeding that "transition" market, Griffiths says,
are other energy drinks with alluring names such as the
powdered energy drink additive Blow (which is
sold in "vials" and resembles cocaine powder) and the
Cocaine energy drink. Both products use the
language of the illegal drug trade.
Griffiths and colleagues are currently collecting case
reports of intoxication from energy drinks
in children and adolescents. Readers interested in learning
more can go to:
www.bpru.org/energydrinks.
Eric C Strain also contributed to this study.