How Much Caffeine Before I End Up in the E.R.?

In 2005, fewer than 2,000 trips to hospital emergency departments involved energy drinks. By 2011, that number was over 20,000.

In 2005, fewer than 2,000 trips to hospital emergency departments involved energy drinks. By 2011, that number was over 20,000. If energy drinks are safe, why are they sending us to the hospital?

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Guarana berries. The seeds contain caffeine at a concentration twice that of a coffee bean. [ggallice/flickr]

The Substance Abuse and Mental Health Services Administration (SAMHSA, a government behavioral health agency) issued a report on Friday that called energy drinks "a continuing public health concern." Yes, energy drinks like Red Bull, 5-Hour Energy, Monster, Full Throttle, CHARGE!, Neurogasm, Hardcore Energize Bullet, Facedrink, Eruption, Crakshot, Crave, Crunk, DynaPep, Rage Inferno, SLAP, and even good old Venom Death Adder.

Everything is a public health concern, though, really. How publicly concerned should we be about energy drinks?

First off, the data from the SAMHSA report looks alarming. It tells us that the number of "energy drink-related" emergency department (ED) visits increased nearly tenfold between 2005 and 2011:

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Energy drinks are not-uncommonly used along with alcohol and other drugs, so SAMHSA (say it aloud once, it's calming) makes the distinction that, of the 20,783 ED visits in 2011, 58 percent involved energy drinks alone; the remaining also involved other drugs.

The rise suggests an increasing propensity for abuse, though, given the rapidly increasing prevalence of energy drinks in the market since 2005 (now a $10+ billion industry), probably a similar percentage of consumers are misusing them and/or having adverse reactions.

Those consumers are more commonly men, and most commonly 18-25-year-olds -- though the over-40 demographic is growing the most rapidly, by degrees (up 379 percent between 2007 and 2011).

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Why are these drinks sending people to the emergency room? The only ingredient(s) in common energy drinks that have been proven to have acute stimulant effects are caffeine and guarana (which SAMHSA defines as "a plant product containing concentrated caffeine"). The vitamins and amino acids that many drinks include shouldn't give you a noticeable burst of energy unless you were previously malnourished and vitamin-deficient. And they're not reasoned to play a role in intoxication effects.

So, essentially, energy drinks can be looked at as caffeine. And as the SAMHSA report puts it, "Large amounts of caffeine can cause adverse effects such as insomnia, nervousness, headache, fast heartbeat, and seizures that are severe enough to require emergency care."

How much is a "large amount" of caffeine? Like alcohol, it's relative to metabolism and tolerance. Most people can tolerate a lot. In caffeine-modified electroconvulsive therapy, for patients with depression, up to 2,000 mg has been given -- intravenously. But that's in a controlled hospital environment where they are trying to give people seizures. And it does increase the likelihood they will have a seizure. For a frame of reference, SAMHSA notes, "The total amount of caffeine in a can or bottle of an energy drink varies from about 80 to more than 500 mg, compared with about 100 mg in a 5-ounce cup of coffee or 50 mg in a 12-ounce cola."

Those examples are a little misleading, though. The Center for Science in the Public Interest (CSPI) has a great list of how much caffeine specific foods/drinks contain. For energy drinks, "more than 500 mg" is far from the norm:

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Center for Science in the Public Interest

Cran-Energy is a thing, yes.

And the 100 mg that SAMHSA cites for a "cup of coffee" is pretty optimistic -- at least in the way that many of us define coffee.

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Center for Science in the Public Interest

Still, despite the fact that a Starbucks venti coffee has three times as much listed caffeine as a can of Monster, some people swear they're more wired after drinking an energy drink. That may be because of the extra caffeine in guarana. Energy drinks can advertise that they have the same amount of caffeine as a cup of coffee; but when you include guarana, they have a much stronger stimulant effect. In Australia, listing quantified guarana content on beverages is mandatory.

The most interesting implication that the report mentions is from a study in which "bar patrons who consumed alcohol mixed with energy drinks were ... four times more likely to intend to drive while intoxicated." Because, as SAMHSA puts it, "Individuals, especially young drinkers, may incorrectly believe that consumption of caffeine can 'undo' the effects of alcohol intake and make it safe to drive after drinking."

That sort of stimulant-empowered bullheaded behavior -- rather than the E.R. admissions for caffeine-induced anxiety -- is actually the most pressing public health concern.

So, caffeinate responsibly. "If I drink another Hardcore Energize Bullet, am I going to have to go to the hospital again?"