A new report out tonight contains a real surprise. In just four years, the number of people who go to the emergency room after drinking energy drinks has doubled, from 10,000 to more than 20,000... See More
A new report out tonight contains a real surprise. In just four years, the number of people who go to the emergency room after drinking energy drinks has doubled, from 10,000 to more than 20,000 people in the e.R. So, what has changed? And what are the drinks doing? Abc's lisa stark has a caffeine experiment of her own. Reporter: On youtube, downing these energy drinks is a game. Lots of fun. Go! Reporter: But this new government study calls consumption of energy drinks a rising public health problem. Of those 20,000 energy room visits in 2011, 42% reportedly had mixed the energy drink with another stimulant, or with alcohol. But 58% reportedly used energy drinks alone. So, what's going on? Blood pressure goes up, heart rate goes up, and then they'll start to feel the effects. Heart racing, heart skipping, panic attack symptoms, irregular heart rhythms. Reporter: Caffeine is a drug -- in fact, the most popular drug in the world. You can feel and see the effects on the body. I downed the equivalent of about four cups. Doctors took a look at my brain before caffeine -- and here's after. The blood flow dropped 40%. It's like a 40% drop in the blood flow to your brain. That's a lot. Reporter: That lower blood flow is still within normal range, but those constricted vessels meant my blood pressure shot up. A cup of coffee won't send you to the e.R. And the most popular energy drinks have less caffeine than that strong cup of coffee you buy out. So what's going on here? There's other substances in them that are completely unregulated that can add to the caffeine or the stimulant nature of the drinks. Reporter: Tonight, the trade association representing the beverage industry said the drinks are safe and denounced the hospital study, saying the limited information makes it impossible to understand the actual role, if any, of energy drinks in these hospital visits. Still, doctors are calling for a whole lot more study and are on the lookout for the next patient to come through the door. Lisa stark, abc news, washington.
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