Energy drinks raise resting blood pressure among the caffeine-naïve: study

A new study shows the link between energy drink consumption and increases in blood pressure and stress hormone responses.

Healthy young adults normally unconcerned by blood pressure should be aware that energy drinks could increase their risk of cardiac events, particularly if they are not used to caffeine, according to researchers at the Mayo Clinic.

"We know that energy drink consumption is widespread and rising among young people. Concerns about the health safety of energy drinks have been raised," says lead author Anna Svatikova, M.D., Ph.D., cardiovascular diseases fellow at the Mayo Clinic.

Dr. Svatikova says her team has proved in prior studies that energy drinks augment resting blood pressure, yet this study calls for the caffeine-naïve to pay careful attention.

Study participants informed the research team of their habitual caffeine consumption and those who consumed less than 160 mg per day -- approximately one cup -- were considered caffeine-naïve.

Working with 25 healthy young adults between the ages of 19 and 40, the researchers gave them either a can of a commercially available energy drink or a can containing a placebo concoction.

The research team assessed blood pressure and heart rate before consumption and 30 minutes afterwards.

All participants who consumed an energy drink underwent a marked elevation in blood pressure compared to those who didn't and the rise was more dramatic in caffeine-naïve participants.

In fact, this group saw their blood pressure increase more than double the amount of the group that received placebo concoctions.

"Now we are seeing that for those not used to caffeine, the concern may be even greater," says Dr. Svatikova. "Consumers should use caution when using energy drinks because they may increase the risk of cardiovascular problems, even among young people."

Dr. Svatikova and her team will present their study on Saturday, March 14 at the American College of Cardiology's  64th Annual Scientific Session in San Diego.

Some dispute what they see as too much marketing of energy drinks to youth, including professional snowboarders Austin Smith and Brian Fox, who in 2011 started a campaign to encourage their young admirers to drink water.

Their website speaks to children and teenagers -- who are even more likely to be caffeine-naïve -- and their "Drink Water" sweatshirts and baseball caps are a common sight at ski resorts.