All through college I had friends who swore that without the help of energy drinks, they would've failed out of school. These fairly normal, health-conscious buddies had no qualms at all about downing a can of Red Bull during a long night in the library, knocking back a shot of 5-Hour Energy before a big presentation, or even chugging a Monster or (gasp!) Four Loko in anticipation of a fun night out on the town. The recent uproar over energy drink-related deaths has raised questions about the presumed innocence of these beverages. Is swigging a chemical-laden elixir a necessary health evil, or is it truly dangerous?Be Alert — The Need-to-Know

It's not exactly news that energy drinks don't qualify as superfoods. But are they actually harmful to our health? Last week, the Food and Drug Administration released files reporting 13 deaths and 90 "health incidents" possibly linked to 5-Hour Energy — a super-concentrated energy shot— in the past four years. The FDA also released reports citing 21 incidents attributed to Red Bull energy drinks. The "incidents" include heart attacks, convulsions, and (freakily enough) one case of spontaneous abortion. The information is especially scary coming on the heels of a similar report released last month, in which the FDA reported five deaths caused by Monster energy drinks. These reports aren't the first to condemn energy drinks. In late 2011, the Substance Abuse and Mental Health Services Administration shared reports that over 13,000 emergency room visits were caused by energy drinks in 2009.

(Also Check Out: How Much Is Too Much Caffeine?)

Even discounting turn-of-the-century sodas laced with cocaine (it's good for the heart, right?), alertness-boosting beverages aren't anything new. In 1962, a Japanese company launched Lipovitan-D, an eye-opening mixture of Vitamin B and taurine, an amino acid found naturally in animal protein that may enhance brain and muscle power. The rest of the world wasn't far behind — in 1982 Austrian entrepreneur Dietrich Mateschitz launched Red Bull, a potent combo of sugar and caffeine. The wing-granting beverage crossed the pond in 1997, and since then the U.S. energy drink market has grown exponentially [1]. In 2010, six states banned Four Loko after people (most of them college students) were hospitalized, and in some cases died, after imbibing the beverage. The drink — a mix of caffeine, alcohol, taurine, and guarana — has been nicknamed "blackout in a can" for its dangerous ability to mask the effects of alcohol consumption. Due to pressure from the FDA, the company has since removed the drink's caffeine components.

Buzz Buzz — Why It Matters

Conventional energy drinks like Red Bull, Monster, Rockstar, and yes, 5-Hour Energy don't contain booze, but that hardly makes them as safe as a sippy cup of apple juice. So what's in those tiny bottles of 5-Hour Energy that are causing so much mayhem?

Plain ole' caffeine is the main chemical ingredient in all of the beverages in question. According to Consumer Reports, one two-ounce bottle of 5-Hour Energy has 215 milligrams of caffeine. On its website, 5-Hour Energy claims one bottle contains the same amount of caffeine as a large cup of coffee — between 100 and 150 milligrams. Does something seem fishy here? While studying the caffeine content of 27 popular energy drinks, Consumer Reports found that many companies under-reported the caffeine levels in their products by an average of 20 percent.

Five-Hour Energy also contains guarana, a plant chock-full of caffeine and taurine. Taurine is naturally found in meat and fish and has legitimate health benefits like supporting neurological development (it's also present in breastmilk) and regulating mineral salts in the blood. Whether it actually improves athletic or mental prowess in adults is not clear. Five-Hour Energy also contains amino acids L-tyrosine and L-phenylalanine, which have very similar effects to taurine. Sounds safe, right? Although the compounds on their own are probably safe to consume, the results of interactions between these chemicals — not to mention oodles of caffeine and sugar — are totally unknown.

Last but not least, energy drinks are loaded with sugar. Five-Hour Energy claims to contain zero grams of sugar, but other brands aren't in league. Red Bull and Monster manage to pour 27 grams of sugar in each serving, while Rockstar hits an even 30 grams per serving. What's the problem with so much of the sweet stuff, anyway? Releasing that much glucose into the bloodstream at once can cause insulin and blood sugar levels to skyrocket. The long-term consequences for high blood sugar — aka hyperglycemia — can be more serious than a mouthful of cavities. Studies show that hyperglycemia can lead to brain shrinkage, type 2 diabetes, and future dementia.

The most dangerous consequence of downing energy drinks is the huge caffeine spike. Taking in huge volumes of caffeine spikes blood pressure and sometimes causes "caffeine intoxication," which can result in serious conditions like tachycardia, vomiting, cardiac arrhythmias, seizures, and in the case of the 5-Hour Energy, 13 deaths [2]. A potent brew of caffeine and sugar almost always results in dehydration. Lots of sugar can make it harder for the body to absorb fluids, which isn't ideal, especially given caffeine diuretic properties [3].

What about those other weird ingredients? Studies show that the levels of additional "energizing" compounds like guarana, taurine, and ginseng are too small to cause noticeable, adverse health effects [4].

The Takeaway

Experts agree that energy drinks can be dangerous because like all drugs (yes, caffeine is a drug, people), they affect every person differently. For a healthy adult, a sip or two of an energy drink shouldn't cause harm, but it's very difficult to predict how chemicals will react in the body. Users are advised to go easy on volume, but energy drinks are often and easily abused. Children and teenagers, people with heart conditions or high blood pressure, the elderly, and pregnant women are especially susceptible to extreme blood pressure and blood sugar spikes that can occur after downing an energy drink.

With so many funky chemicals involved, it's a wonder people turn to energy drinks for that extra boost. To energize safely, stick to a tried-and-true method like drinking water, taking a walk outside, or simply getting enough sleep.

Do you think 5-Hour Energy and other energy drinks are dangerous, or just unhealthy? Join the conversation below or tweet the author at @SophBreene.