Health Team

Health Official: Energy Drink Jolt May be Harmful to Some

Posted November 8, 2007 4:51 p.m. EST
Updated November 8, 2007 7:01 p.m. EST

These days, high energy drinks fill a larger space on store shelves. But most of them pack more than just a high dose of caffeine.

The drinks also boast ingredients to rev people up, which may help some students pull off all night study sessions or help others stay awake at the wheel.

There's a new warning that affects as many as one in three adults.

Michael Schulze, 20, pops open energy drinks every day.

“I drive three hours a day,” he said. “I’m generally tired from lack of sleep, working late, whatnot.”

That extra jolt helps with his job. It may keep him alert, but a new study from the American Heart Association showed that boost can also affect the heart.

Every day for one week, healthy participants drank two cans of an energy drink with 80 milligrams of caffeine and 1,000 milligrams of taurine - a protein that also affects the heart.

“There was an increase in both blood pressure and heart rate in four hours after drinking these energy drinks,” said James Kalus, with Henry Ford Hospital.

Kalus, who was the lead author of the study, said heart rates increased five to seven beats per minute - and with rises in blood pressure. But the participants were sitting, not exercising.

The results didn't show problems for healthy people, but researchers said it may be harmful to people with heart or blood pressure problems.

“Patients who know they have a cardiovascular disease should avoid these drinks before we know more about what they do to patients with high blood pressure or [cardiovascular disease],” Kalus said.

Schulze said his stomach hurts and he gets a little fidgety when he has too many energy drinks.

He has also learned about other ingredients, such as niacin.

“[It] actually makes your entire body feel like it has needles going through it,” Schulze said.

But he's not willing to give up energy drinks just yet, he said.

The American Beverage Association says the drinks are safe and have a similar amount of caffeine as a cup of coffee. But the researchers say additives may interfere with blood pressure medication.