Combining alcohol and caffeine in the same drink is popular. But now there is growing concern it could be more dangerous than first thought. Fox 23's Douglas Clark explains why the FDA is now investigating nearly 30 manufacturers of alcoholic energy drinks. Combining alcohol and caffeine is nothing new. But health officials are growing increasingly concerned over its effects on the body. Whether pre-mixed in a can or poured at the bar, alcohol and caffeine has become a popular party drink. “It’s a tasty combination,” says bar customer Jeff Bean. “We go through a case or two of Red Bull a night,” says bartender P.J. Evans. But why is the combination so popular? Those who drink it say the caffeine counter-acts the effects of the alcohol. “It’s a tug-of-war. You’ve got the effects of the alcohol and the caffeine that might put you in a good mood for the rest of the night and not make you so sluggish,” says Bean. And that’s exactly why health officials are worried. In a letter to the FDA supporting its scrutiny of alcoholic energy drinks, Oklahoma Attorney General Drew Edmondson said studies show “caffeine appears to mask the intoxicating effects of alcohol, but not reduce the drinker’s level of intoxication. People who consume these drinks often do not realize how intoxicated they are.” “I don’t know if it affects you as strongly, maybe, because you’re more awake and it’s not draining you, I guess. You probably don’t think you feel it as fast. You probably do, but you don’t realize it,” says bar customer Austin Beeler. As a result, experts fear that could lead to more drunk driving, violence, and sexual assaults. The FDA is now looking into the safety and legality of dozens of pre-mixed alcoholic energy drinks, since it officially does not approve of adding caffeine to alcohol. Last year, under scrutiny from a group of states including Oklahoma, Anheuser-Busch and Miller-Coors stopped making alcoholic energy drinks. But that hasn’t stopped others from hitting the market.