Energy Drinks Jolt the Heart
Popular Drinks Boost Blood Pressure, Heart Rate
WebMD News Archive
Nov. 6, 2007 (Orlando, Fla.) -- Energy drinks may boost your blood pressure and heart rate as well as your
vitality, researchers say.
In a small study, they found that drinking just two cans of a popular drink
increased blood pressure and heart rate within four hours.
While the increases didn't reach dangerous levels in the healthy volunteers
studied, they could be harmful for people with heart disease or who are taking medication to control
blood pressure, says James Kalus, PharmD, senior manager of patient care
services at Henry Ford Hospital in Detroit.
"These people should avoid these drinks," he tells WebMD.
How about people at high risk of heart disease due to obesity, smoking, family history, or other factors?
"Pending more study, at least talk to your doctor about potential
risks," Kalus says.
The findings were presented at the American Heart Association's (AHA)
Scientific Sessions 2007.
Energy Drinks Raise Blood Pressure
In the study, 15 healthy young men and women drank two cans of an energy
drink that contained 80 milligrams of caffeine every day for a week. All agreed
to abstain from any other forms of caffeine for two days prior to and
throughout the study.
Within four hours of consuming the drinks on the first day, systolic blood
pressure (the top number) shot up by 9 points; on the seventh day, it rose 10
points. Diastolic blood pressure (the bottom number) rose 5 points on both
days, Kalus says.
Heart rate increased five beats per minute on the first day; seven days on
The volunteers were sitting in a chair, watching a movie, when the changes
occurred, he says.
In contrast, many young people mix the energy drinks with alcohol and
dancing. And some of the marketing for energy drinks is aimed at extreme
sports, he says.
Since it wasn't studied, Kalus says he can't say for certain that mixing
energy drinks with booze or exercise raises the risks. But some countries
advise against using energy drinks to quench thirst while playing sports,
according to the AHA.
And just yesterday, researchers reported that college students who mix
alcohol with energy drinks are at higher risk for alcohol-related injuries than
students who drink cocktails alone.