While the makers of Red Bull claim their ragingly popular beverage “gives you wings,” a new study suggests that the taurine- and caffeine-based energy-enhancer may also give you a higher risk of having a stroke or heart attack.

Drinking one 250 ml can of sugar-free Red Bull increased the “stickiness” of a drinker’s blood, causing a higher risk of blood clots, which can be a precursor to life-threatening strokes, according to a study released last month by the Cardiovascular Research Centre at the Royal Adelaide Hospital in Australia.

In response to the study, the drink’s manufacturer issued a statement, stating that “the study does not show effects which would go beyond that of drinking a cup of coffee. Therefore the reported results were to be expected and lie within the normal physiological range.”

David M. Greer, an assistant professor of neurobiology at Mass. General Hospital, said that while caffeine increases blood pressure, he was unaware of any study showing that coffee or caffeine could increase blood’s “stickiness” or viscosity.

Although Greer said that an increase in viscosity could lead to a stroke, he said that the correlation between the beverage and heart problems suggested by the study is rather tenuous without further research.

“Many conditions lead to an increase in blood viscosity, such as dehydration,” he said. “Even though many people get dehydrated, that doesn’t mean that they have strokes.”

Harvard students that said they rely on the energy drink to fuel their all-night study sessions, said the study’s results come as a surprise.

“I started drinking Red Bull a year ago to help me cope with Organic Chemistry,” said Cody Colon-Berezin ’09, a biology concentrator in Winthrop House.

Colon-Berezin said he stopped drinking Red Bull after his stepfather printed the results of the study for him to read.

“I am at this point going to be cautious and cross it off my menu until I can look at the study more closely,” he said.

Red Bull isn’t trendy just among the academic set—the drink is also popular among late night club-goers, according to those who work at local bars.

The Grafton Street Restaurant and Bar goes through several 48-can cases of Red Bull a week, according to bartender Paul Barry.

Barry said that he has been serving Red Bull and vodka for the past several years, with the drink gaining popularity among patrons between the ages of 21 and 35.

“Older people tend not to order it,” he said. “They don’t need to be too energetic anymore.”

A study last year conducted by the Henry Ford Hospital in Detroit demonstrated that Red Bull increases heart rate and blood pressure.

Another study, presented last year to the American Public Health Association in Washington, found that people who drink Red Bull with alcohol are twice as likely to be hurt or injured during a night out.

Red Bull is banned in Norway, Uruguay, and Denmark because of previous documented health concerns.

But Greer said it was too soon to advise young people to stop drinking Red Bull altogether, calling for a double-blind placebo study before making definitive recommendations.

“It’s far too soon to tell,” he said. “Trying to tell someone that age not to drink Red Bull is like telling them not to go to a bar. It’s just done so frequently.”

—Staff writer Alexander B. Cohn can be reached at abcohn@fas.harvard.edu