August 18 (HealthDay News) -- Drinking too much of the popular Red Bull energy drink may lead to heart damage, says an Australian study that included 30 university students, ages 20 to 24.

The researchers found that drinking just one 250 ml sugar-free can of the caffeinated drink boosted the "stickiness" of the blood and increased the risk of blood clots. After drinking Red Bull, the students had a cardiovascular profile similar to that of someone with heart disease, the Times (U.K.) reported.

The results were alarming and suggest that older adults with symptoms of heart disease shouldn't drink too much Red Bull, said study author Scott Willoughby, of the Cardiovascular Research Center at the Royal Adelaide Hospital and Adelaide University.

In a statement, Red Bull officials said the drink had been proved safe by numerous scientific studies, and that it had never been banned from anywhere it had been introduced, the Times reported.

Red Bull is sold in 143 countries but is banned in Norway, Denmark and some other countries due to health concerns.