Energy drinks are everywhere. How dangerous are they?

If you believe the ads, energy drinks turn ordinary schnooks like you and me into lean, mean, git-her-done machines. They promise to give you wings, unleash the beast, make you the boss of time, and enable the crushing of your enemies. No wonder sales have boomed in recent years, growing by 73 percent from 2018 to 2023. Nearly half of consumers drink them multiple times a week. In addition to the offerings at retail and convenience stores, chains like Starbucks, Dunkin, and Caribou Coffee are adding energy drinks to their menus. In the next five years, energy drink sales are on track to reach $30 billion in the US. The vast majority of the people who drink energy drinks — mostly teens and men aged 18 to 34 — don’t die as a result. Occasionally, though, some do. The Center for Science in the Public Interest counted 34 deaths linked to these products between 2004 and 2014. More recently, the families of a female college student and a 46-year-old man sued Panera over the deaths of their loved ones following consumption of its highly caffeinated Charged Lemonade drinks. A far larger chunk of people who consume energy drinks experience other unpleasant side effects as a result, ranging from sleeplessness to twitchiness to anxiety to gastrointestinal distress. Still, demand for these products is mounting, even outside of their sweaty core constituency. That’s not an accident: As the current male market has neared energy drink saturation, manufacturers have set their sights on adults beyond college age — especially women, according to a recent report from market analysis firm Mintel. They’re reaching these new mouths by capitalizing on a growing and somewhat whimsical demand that the liquids we drink not only quench our thirst, but also reduce our stress, focus our minds, and improve our physical performance. That’s why, despite the persistent drip-drip of deaths that trails the industry, energy drink manufacturers are bullish (sorry) about their future. Energy drinks contain a variety of stimulants, some of which we understand better than others Energy drinks’ wakefulness-boosting qualities come by virtue of their ability to get stimulants into your bloodstream with cold, sweet efficiency and only an occasional metallic aftertaste. In addition to lots of added sugar, almost all energy drinks add caffeine to their formulations. Many also include guarana, an Amazonian plant that contains high levels of naturally occurring caffeine and other stimulants. Another common ingredient is taurine, a building block of proteins that occurs naturally in the human body and actually has the effect of tamping down the activity of certain nerve cells. In moderate amounts, caffeine makes people feel more alert, attentive, and energetic. However, in larger amounts, its negative effects — including jitteriness, nausea, and tremor — may overwhelm the positive. Scientists know surprisingly little about taurine’s and guarana’s toxicities in humans — most of the safety data for these products comes from animal studies — but they know a lot more about caffeine’s effects on various human organ systems. Many of those effects depend on how often and how much of it you consume: Although a big cup of coffee won’t meaningfully affect blood pressure or heart rate in people who are daily coffee drinkers, it could spike both in non-coffee drinkers, and large quantities can lead to serious side effects, including severe recurrent vomiting, seizures, and muscle breakdown. There’s also enormous variation in the amount of caffeine energy drinks contain. A typical 8-ounce cup of coffee has around 100 to 150 milligrams of caffeine. Filling the same cup with Monster Energy gives you only 80 milligrams, while filling it with 5-Hour Energy (four shot-sized bottles’ worth, something I implore you not to do) would give you 800 milligrams. (The Food and Drug Administration recommends a daily maximum of 400 milligrams of caffeine for most adults, a guideline based on recommendations issued by Canadian public health authorities.) Meanwhile, a large cup of the now-discontinued Panera Charged Lemonade, without ice, could contain 390 milligrams of caffeine. Because they were initially sold in self-serve dispensers, customers could easily free-refill their way to several days’ allowance of caffeine in one sitting. (The largest size of Starbucks’s Iced Energy tops out at 205 milligrams, and refills are not free.) How energy drink ingredients can lead to medical emergencies Although energy drinks have been linked with a range of worrisome health effects, some of the biggest concerns are related to their effects on the cardiovascular system and the heart’s rhythm in particular. Several studies have shown energy drinks raise heart rate and blood pressure, which in extreme cases can lead to spasms, rips, or clotting in blood vessels. They have also been linked to disruptions to the heart’s wiring that in certain higher-risk people could lead to cardiac arrest — when the heart stops beating entirely. One out of every 200 people have a genetic heart condition of some kind that puts them in that high-risk category, says Michael Ackerman, a cardiologist at the Mayo Clinic in Rochester, Minnesota. The most common circuitry problem in that group is called long QT syndrome, which affects one out of every 2,000 or so people. Ackerman counsels people with this syndrome to avoid medications, foods, and beverages (like energy drinks) that irritate the heart’s wiring, and occasionally prescribes medication to reduce their risk of having a rhythm problem. However, the condition is often asymptomatic and therefore may go undiagnosed until someone has symptoms. It’s not clear exactly which ingredients in energy drinks are responsible for throwing a wrench in the heart’s circuitry. Caffeine seems as though it would be the most likely culprit — in pure and highly concentrated forms, the drug can be lethal — but in clinical studies of smaller amounts of caffeine on its own, it doesn’t seem to cause heart wiring changes or rhythm problems. (However, outside of closely monitored study settings, people are probably drinking larger quantities of energy drinks at a much faster clip; it may be that researchers have simply never studied the caffeine-related effects of real-world levels of energy drink consumption.) The effects of energy drinks’ other ingredients on heart rhythms are an even bigger question mark, although some studies suggest interactions between multiple ingredients may disrupt heart rhythms. Ackerman has been asking his patients about energy drink consumption since 2000 and recently conducted a small study looking back at the medical records of the 144 patients he evaluated after they survived a cardiac arrest. Seven of them — 5 percent — had consumed an energy drink shortly before their hearts stopped beating. Only one of those seven had a previous diagnosis of a heart condition known to make energy drink consumption more risky. One detail of the study was particularly eye-catching to me: Six of the seven patients with post-energy-drink cardiac arrest were women. Ackerman said that’s likely related to estrogen’s propensity to induce heart rhythm fritziness in people with long QT syndrome. Still, the finding seems deeply ironic given that women have historically consumed far fewer energy drinks than men. This is a tiny study, and Ackerman cautions against overreacting to its findings. “Consumption is at all-time-high levels, and people aren’t dropping like flies left and right,” he says. “The absolute risk, if your heart is healthy, is super, super, super low.” Still, many energy drinks are marketed as supplements and can therefore claim to do all kinds of things without proof, says Jensen Jose, who works on regulation issues related to food additives, food chemicals, and dietary supplements at the Center for Science in the Public Interest. They can do so without giving you the information you need to moderate your intake of caffeine or other proven or potential compounds that stimulate or irritate the cardiovascular system. Although a product label may list caffeine and guarana extract, says Jose, “You have no idea how much caffeine you’re getting from either one of those ingredients.” An FDA loophole means there aren’t legal limits on the amount of caffeine in any of these products, nor does the agency require manufacturers to tell you how much caffeine is in them. How should consumers who like energy drinks keep themselves safe? “There’s no answer to your question,” says Jose, in large part because so little is known about what’s in a lot of these beverages and what intake levels make the most sense. Still, consuming only drinks that list their caffeine content — and consuming those in moderation, ensuring you’re staying under the FDA’s recommended daily limit — is, he says, better than mindlessly pounding one can after another. Although Ackerman doesn’t think the drinks’ sale should be restricted, the risk-benefit equation doesn’t at all tilt toward consuming them. “They don’t have much redeeming health value anyways,” he says. The Centers for Disease Control and Prevention recommends kids and teens avoid energy drinks entirely. Energy drinks began as a product marketed toward men, but that’s changing The modern energy drinks’ closest ancestor is probably the Japanese Lipovitan D, which first rolled out in 1962. Powered by a combination of taurine, caffeine, and other ingredients, these drinks were marketed with an emphasis on a hegemonic fight/burn/roar sleep-is-for-the-weak type of masculinity. In the 1980s, an Austrian businessman’s encounter with a Thai beverage containing taurine and caffeine led to the creation of Red Bull, the first entry into the modern Western energy drink canon. The market has only grown since, spurred by partnerships with the growing extreme sports and video gaming industries, which already attracted hordes of teen boys extremely receptive to messaging aimed squarely at their desire to prove their masculinity. In 2015, psychologist Ronald Levant found that among white college-aged men, energy drink consumption was driven by an embrace of traditional masculine ideology, which defines “real men” as tough, dominant, horny, handy, homophobic, and unemotional (unless mad or triumphant). Much of this effect was about boys seeking ways to be more manly, he tells Vox: “They're looking for ways to enhance their masculinity, and they saw energy drinks as a way to do that.” The aspiration to that kind of manliness is still alive and well on what commentator Max Read has called the Zynternet, the “fratty, horndog, boorishly provocative” corners online. The people occupying those corners and the men in their social networks still comprise a big part of the target audience for many energy drink brands. Because energy drinks have leaned so hard into their associations with traditional masculine norms, you might imagine they’d have a hard time finding audiences among groups less interested in beating their chests and peeing on things. Several years ago, however, manufacturers began a concerted effort to change that and started targeting tired, distracted women and post-college adults looking for solutions to their droopiness. Enter Alani’s saturated tropical swirls, Celsius’ fruit-forward flavors and packaging, Red Bull’s curuba elderflower “Summer Edition,” and the no-longer-in-production Go Girl. Russell Zwanka, who directs the food marketing program at Western Michigan University, says the pivot to young adults and women was unambiguous and long overdue. The trend that’s enabling this more expansive view of the energy drink audience is the consumer itch for beverages that do things, says Zwanka. “All marketing is now geared toward, ‘What is the function of the beverage?’” he says. In food marketing parlance, functional beverages contain biologically active compounds that give them specific health benefits. Currently, the most highly sought-after benefit is one you’d think would be a slam-dunk for something you slurp from a can: “Hydration has been by far the trend for the last year and a half. It is off the charts,” says Zwanka. To take energy drinks at their word, you’d have to forget they’re actually unlikely to provide better hydration than Gatorade or milk, especially because at higher doses, caffeine functions as a diuretic — that is, it actually drives water loss through increased urination. Energy drinks are promising it anyway, and so much more, because there’s simply not that much regulatory oversight on what’s in them or how they're marketed. That’s doing a great disservice to Americans, says Jose. “We want transparency in our food system,” says, “and we think that’s a pretty obvious first step.”