Back Away from the Can: Just One Red Bull Increases Stroke Risk

By Anastacia Mott Austin

You knew it was too good to be true, didn’t you?

It turns out that Red Bull, the most popular energy drink in the world, can cause your blood to get "sticky," and therefore increase stroke and heart attack risk, with just one can, even if you’re a young, healthy person.

Not so delicious now, is it?

The study, led by Scott Willoughby, from the Cardiovascular Research Centre at the Royal Adelaide Hospital in Australia, tested 30 young adults one hour before, then one hour after consuming one can of Red Bull energy drink.

The changes in the subjects were startling. Said Willoughby to reporters, "One hour after they drank Red Bull, (their cardiovascular systems) were no longer normal. They were abnormal like we would expect in a patient with cardiovascular disease."

Willoughby said that after performing the study, the results were such that he would not choose to drink Red Bull himself.

What happened was that the test subjects’ blood became what researchers call "sticky," or far more likely to clot, creating the increased risk for stroke, heart attack, and other cardiovascular problems.

Think you’re in the clear because you only drink the sugar-free version? The test was conducted on the sugar-free brand of Red Bull.

The Austrian-based company that developed Red Bull, Red Bull GmbH, created it in 1987 as an energy drink. It didn’t really catch on until about five years ago, but since then it’s caused a sensation. The company sold more than 3 billion cans of the stuff in 2006, in over 130 countries.

Not everyone’s always been in love with Red Bull, though. The beverage is currently banned in Norway, Iceland, Uruguay, and Denmark, due to concerns about its high taurine content, and several deaths that may have been linked to the drink. Common side effects include jitteriness, insomnia, raised blood pressure, and some concerns have been raised about its connection with anemia.

The can itself carries a warning label to not consume more than two cans per day, not to mix with alcohol, and that people sensitive to caffeine should use caution when drinking it.

But so far it has not been required to warn drinkers of its tendency to cause sticky blood.

Red Bull Australia representative Linda Rychter said the company would need to review the study, but that first glance told them that Red Bull does not seem to cause any effects that drinking a cup of coffee with sugar wouldn’t.

Dr. Willoughby would disagree. "If you get an increase in stickiness and a decreased ability of the blood vessels to stop its stickiness, that adds up to a bad situation," he said.

"If you add in other risk factors for cardiovascular disease - stress or high blood pressure - this could be potentially deadly."

Added Willoughby, "The can currently comes with a warning of its own. But if you have any predisposition to cardiovascular disease, I'd think twice about drinking it."