Energy Drinks Affect Heart, MRI Scans Show
Small, early study found contraction rate sped up after people downed beverage
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 prepared statement.
"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 Also, this paper, which looks at only 18 adults, has not been peer-reviewed or published."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 done.
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."