Energy Drinks and Caffeine Toxicity (“The Good, The Bad and The Ugly”)

by Sheela Doraiswamy on October 1, 2012

I’d like to imagine that you read my advice last week, took it to heart, and swore to always get sufficient sleep. What you probably actually did was consider my advice, but then come across an ad like this one, that Red Bull is distributing on this very campus-

I do, actually, but that’s probably just me (photo taken by me)

Maybe they have a point–why bother with sleep when you can just drink a can of Red Bull, Monster, Rockstar, etc, and get almost the same effect?

A study published in Nutrition Journal(Maulinaskas et al)  looked at the behaviors, beliefs, and effects associated with energy drink consumption at a college campus. Another article published in the journal Clinical Nurse Specialist (O’Malley) provides a review of the negative side effects linked with energy drinks.

Let’s take a closer look at these articles and explore “The Good, The Bad, and The Ugly” of energy drinks- (feel free to listen to this while you read)

The Good: Increasing Cognitive Function

On the inside of that ad (pictured below), Red Bull says that their product improves performance and concentration.

photo taken by me

Well, the good news is that they’re not lying. As you probably know already, one of the main ingredients  in energy drinks such as Red Bull is caffeine. In small doses (about 12.5 to 50mg), caffeine has been found to improve cognitive performance and mood, and a higher dose of 200mg can increase cognitive task speed and alertness.

It makes sense, then, that the majority of students in this study said they consumed energy drinks due to insufficient sleep, to get energy for late-night cramming or working on a project, or to mask the effects of alcohol. It almost seems like energy drinks are a liquid solution to all your problems!

So 200mg of caffeine seems OK. That leads to a couple other questions- 1) How much caffeine is in an energy drink and 2) What happens when we drink too much?

This is definitely NOT what happens. Comic courtesy of Justin Boyd,


The Bad: Caffeine Toxicity

The amount of caffeine in an energy drink can range from 50 to 505 mg per serving (depending on brand, size, etc).  A large number of the students in Maulinaskas et al’s study also tended to drink more than one can at a time, and therefore were more likely to drink more than the recommended 200mg. Drinking high doses of caffeine can lead to caffeine toxicity, which can cause physiological and psychological problems.

One of the studies discussed in O’malley’s article tested the effects of a caffeine dose of 120mg versus 360mg on college students. Those who had consumed 360mg of caffeine from energy drinks had significantly increased blood pressure and heart rates, and all of them also experienced anxiety and insomnia.  In Maulinaskas et al’s study, about 22% of students also experienced headaches, and 19% had irregular heart beats.


The Ugly: The “Pharmacological Molotov Cocktail”

19% of students getting irregular heartbeats might not sound so bad. However, these effects are amplified when energy drinks are mixed with other substances, such as alcohol or certain medications (O’Malley refers to this as a “pharmacological Molotov cocktail”).

The mixture of energy drinks with medicines for ADHD and/or antidepressants can cause excessive stress on the kidneys, liver, and brain. A 2007 study referenced in this article even found that teens and young adults with eating disorders, or ADHD are at a higher risk for heart attacks or other heart problems after consuming energy drinks, possibly due to mixing high doses of caffeine with other medications.

We see similarly heightened negative effects when energy drinks are mixed with alcohol. Malinauskas et al’s study found that 73% of students did this so that they could mask the depressant effects of alcohol. In other words, they could drink seemingly without actually “getting drunk.” According to another study , students who mixed alcohol with energy drinks were 6 times more likely to have heart palpitations, and were also more likely to experience insomnia, anxiety, and tremors.


Energy drinks are relatively new, and there’s still a lot of research to be done on them as far as health effects go. If you want to use energy drinks, don’t just blindly drink several at a time. Look closely at the amount of caffeine and try not to exceed 200mg in one day. (Edited 10/3/2012 to include timeframe)

If you have any medical conditions discussed above, be aware that your risks are higher. And finally, remember that you increase your risk of heart palpitations, insomnia, anxiety and tremors by mixing an energy drink with alcohol.