 The first energy drink dates back more than a half century. Doctor Enough launched in 1949. Now there are more than 100 brands. An industry now selling 50 billion dollars of the stuff a year. They're popular on military bases, but some military leaders have questioned their safety based on data like this. The skyrocketing number of energy drink-related emergency room visits over recent years. But if you look at some of the reports, you see cases like this. 24-year-old guy who didn't feel well after drinking a can of energy drink and three bottles of vodka. Because energy drinks are often co-consumed with other substances, it's hard to tease out the culprit. Same problem with population studies. Sure, adolescents drinking energy drinks are at risk of a wide range of negative outcomes, but energy drink consumers are also more likely to drink soda and have other unhealthy habits, more likely to binge drink, take diet pills, and engage in other risky behaviors. So the only way to tease out the energy drink component is to put it to the test. One of the concerns that has been raised by public health advocates in terms of potential negative effects is increased blood pressure. But have people chug a can of Red Bull and 30 minutes later no significant change in blood pressure? Okay, but that was the little 8-ounce can? What about the 16-ounce big cans of Red Bull? 40 minutes later, no significant change there either. So concerns about energy drinks raising blood pressure were dismissed as overblown until the bomb dropped in 2014. Red Bull did indeed significantly raise blood pressure after all. The reason the earlier studies missed it is because the spike doesn't start peaking until like an hour after consumption. So if you just look at like 30 minutes after consumption, all seems fine, but the worst is yet to come. And the big shocker was that cerebral blood flow velocity. Blood flow in the brain took a dive. Energy drinks are promoted as having beneficial effects, but this instead would suggest they're potentially harmful because of the extra cardiac workload and decreased brain blood flow velocity. Researchers subsequently looked at other brands. Here's Rockstar brand energy drink, significantly elevating blood pressure within just 30 minutes. Yeah, but wait a second. Is it just the caffeine? I mean, is there any difference in just drinking a cup of coffee? To figure that out, you'd have to compare the effects of an energy drink with just a plain drink with the exact same amount of caffeine. But there's never been such a study. Until now, a randomized, double-lime, controlled crossover study, in which young, healthy volunteers were randomized to drink two large cans of an energy drink or a controlled drink that had the sugar and the same amount of caffeine, but none of the other proprietary blend ingredients like taurine, quarantine, ginseng, guarana, and all the other stuff they had. And it turns out it wasn't just the caffeine, significantly higher blood pressure on the energy drink than the exact same amount of caffeine in the control group. What's this higher QT interval thing, though? On NKG, it's the distance from the beginning of the downward Q wave to the end of the bump of the T wave. Okay, so who cares? QT prolongation, which is what the energy drink did, but not the caffeine, is a recognized marker of increased risk of fatal arrhythmias, fatal heart rhythms. That doesn't sound good. Okay, but by how much? Prolongation of the QT interval by more than 60 milliseconds is a marker for life-threatening arrhythmias, and the energy drink only prolonged it by about 10. But there have been drugs pulled from the market, profitable drugs bringing in billions of dollars because of a 5 to 10 millisecond prolongation. So we really need to start investigating some of these other ingredients in energy drinks. For example, in 2008, authorities found cocaine in Red Bull drinks. The Red Bull manufacturer insisted, however, that they were just adding the coca leaf for flavor, and that all the active cocaine was removed.