MONDAY, Dec. 2, 2013 (HealthDay News) -- Energy drinks may
provide a bit too much of a boost to your heart, creating
additional strain on the organ and causing it to contract more
rapidly than usual, German researchers report.
Healthy people who drank energy drinks high in caffeine and
taurine experienced significantly increased heart contraction rates
an hour later, according to research scheduled for presentation
Monday at the annual meeting of the Radiological Society of North
America, in Chicago.
The study raises concerns that energy drinks might be bad for
the heart, particularly for people who already have heart disease,
said Dr. Kim Williams, vice president of the American College of
"We know there are drugs that can improve the function of the
heart, but in the long term they have a detrimental effect on the
heart," said Williams, a cardiology professor at Wayne State
University School of Medicine, in Detroit.
For example, adrenaline can make the heart race, but such
overexertion can wear the heart muscle down, he said. There's also
the possibility that a person could develop an irregular
From 2007 to 2011, the number of emergency room visits related
to energy drinks nearly doubled in the United States, rising from
slightly more than 10,000 to nearly 21,000, according to a meeting
news release. Most of the cases involved young adults aged 18 to
25, followed by people aged 26 to 39.
In the new study, researchers used magnetic resonance imaging
(MRI) to measure the heart function of 18 healthy participants both
before and one hour after they consumed an energy drink.
The energy drink contained 400 milligrams of taurine and 32
milligrams of caffeine per 100 milliliters of liquid (about 3.4
ounces). Taurine is an amino acid that plays a number of key roles
in the body, and is believed to enhance athletic performance.
Caffeine is the natural stimulant that gives coffee its kick.
After downing the energy drink, the participants experienced a 6
percent increase in their heart contraction rate, said study
co-author Dr. Jonas Doerner, a radiology resident in the
cardiovascular imaging section at the University of Bonn, in
It appears that the unique blend of sugar, caffeine and taurine
in an energy drink may combine to have an effect on the heart,
Doerner said. He and his colleagues tested a second group using a
drink containing only caffeine, but those patients did not show a
significant increase in heart contractions.
"Maybe the mechanism could be from the taurine, or from the
combination of taurine and caffeine," he said.
Because this study was presented at a medical meeting, the data
and conclusions should be viewed as preliminary until published in
a peer-reviewed journal.
The American Beverage Association responded to the study with a
"The fact remains that most mainstream energy drinks contain
only about half the caffeine of a similar size cup of coffeehouse
coffee," the industry group said. "Caffeine is a safe ingredient
and is consumed every day in a wide variety of foods and beverages,
including energy drinks which have been enjoyed safely by millions
of people for nearly three decades. Also, this paper, which looks
at only 18 adults, has not been peer-reviewed or published."
Doerner was reluctant to speculate on potential damage to the
heart that could result from long-term energy drink consumption,
given that his study focused only on short-term effects.
"We have shown that even small amounts of energy drinks alters
heart function," he said. "Because of that, further investigation
needs to be done to address concerns regarding long term effects on
kids and long-term effects on people with heart disease."
However, Doerner did advise that children and people who have an
irregular heart beat should avoid energy drinks until more study is
Cardiology professor Williams agreed that further research is
needed, adding that these results need to be followed up.
"Without data, one can only speculate," he said. "If you
speculate on existing drugs that have that effect, it would be
cause for concern."
To learn more about taurine, visit the
NYU Langone Medical Center.