While studies on wine and coffee sometimes deliver good news (that, you know, it's fine to drink them), that's almost never the case with energy drinks. They've already been found to have short-term impacts on heart health , and to be dangerous (and stunningly widespread) cocktail mixers . Then there's the incredibly high amounts of sugar and caffeine in them — red flags on their own. And yet, that hasn't stopped energy drinks from becoming an industry worth nearly $50 billion Weirdly enough, most people who purchase and consume energy drinks do worry about how they affect their health. Of course, that doesn't keep them from buying the stuff. As this video from Discovery News explains, caffeine is an addictive substance, and you come to crave more of it as your body grows accustomed to its effects. This is how your coffee dependence works, too, but when it comes to energy drinks, additional stimulants (like ephedrine, guarana, and taurine) intensify the effects of the caffeine.The video refers to a study from the Mayo Clinic, which suggests that a single energy drink can trigger physical changes that increase your chances of cardiovascular problems later on. Another study found that the drinks may have negative effects on your behavior, leading to a noticeable increase in irritability and nervousness. In other words, we're starting to understand more about both the immediate and long-term effects of energy drinks, and none of them are particularly great.