A cocktail of alcohol and energy drinks poses a greater health risk than just drinking alcohol, according to a University of Michigan and Penn State study. Researchers said that these concoctions, which are super popular among teenagers and young adults, can cause strokes, alcohol poisoning, black-outs and other health problems.

The U.S. does not authorize manufacturers to premix high-caffeine products with alcohol. However, teenagers and young adults continue to create their own versions of energy drinks, pouring hard liquor into caffeinated soft drinks. Mixed drinks such as vodka Red Bulls and Jäger bombs are made by just dropping a shot of Jägermeister liquor into a glass of Red Bull.

These drinks can lead to an intoxicated state known as 'wide-awake drunk' because caffeine is presumed to soothe some of alcohol's sedative effects, the researchers wrote in the study.

"We found that college students tended to drink more heavily and become more intoxicated on days they used both energy drinks and alcohol, compared to days they only used alcohol," Megan Patrick of the University of Michigan Institute for Social Research and lead author of the study said in a press release.

For the study, Patrick and Jennifer Maggs of Penn State observed 652 college students over a period of four semesters. During the study, students answered questions about their energy drinks and alcohol consumption and were asked to report any negative consequences they experienced (hangovers included).

"Our findings suggest that the use of energy drinks and alcohol together may lead to heavier drinking and more serious alcohol-related problems," Patrick said. "As energy drinks become more and more popular, we should think about prevention strategies for reducing the negative consequences of using energy drinks and of combining energy drinks with alcohol."

The new study titled 'Energy Drinks and Alcohol: Links to Alcohol Behaviors and Consequences Across 56 Days,' has been published in the Dec. 2 issue of the Journal of Adolescent Health.

Vodka Red Bulls and Jäger bombs are variations of the recently-banned Four Loko and Sparks. The two drinks were among the many alcoholic energy drinks that were banned in the last few years after a series of alcohol-related illnesses, according to Medical Daily.