LAS VEGAS -- Another new study is out regarding Red Bull Energy Drink, and it doesn't help the beverage's reputation with doctors.

According to new research out of Australia, the drink can cause symptoms of cardiovascular disease after just one drink.

The target audience -- and those who consume the majority of the drinks -- for Red Bull and other energy drinks are people in their 20s. Researchers said these people, who are usually students, use the boost to study for classes.

Those students who took part in the study showed a cardiovascular profile of someone with heart disease, again after just one can of Red Bull. After one, sugar-free drink, the study found that the participants' blood increased in stickiness, raising the risk of blood clots forming.

Energy drinks are known to boost heart rates and blood pressure, so this new study is just another red flag, according to doctors. They warn against consuming energy drinks, but said if you're going to do so, do it in moderation.

"A can of Red Bull may not be a health risk," Dr. Mike Karagiozis said. "But three or four drinks would be the equivalent of sitting in a sauna or dancing on a dance floor."

In other, unrelated studies, Karagiozis said research has proved that studying on energy drinks and caffeine may help you retain less information.

Sleep is still the best energy booster, he said.