Energy Drinks May be Risky

Caffeine infused beverages drawing scrutiny

/ Author:  / Reviewed by: Chris Galloway, M.D.

Energy drinks may be all the rage for a certain set of on-the-go young people, but are they safe?

These caffeinated concoctions are said to help people focus, overcome lethargy, and provide fuel for a night of partying. Now, some researchers say there are risks involved, especially when mixed with alcohol, and that energy drinks need more scrutiny.

Americans love their coffee, and energy drinks can be thought of as just another delivery system for caffeine, one of the world's favorite drugs, and one of the very few enjoying something with establishment approval.

Back in the 1990's there was a brief surge in publicity for Jolt Cola, which was promoted as having "All the Sugar and Twice the Caffeine".  This edgy marketing pitch may have raised eyebrows, but the bourgeois associations of coffee and it's reputation as a productivity enhancer have generally made caffeine seem rather tame as far as stimulants go.

The market for these beverages keeps growing. One can find them at many if not most convenience stores, but also in bars.

The ads and branding make it seem as if energy drinks are a party or nightlife enhancer. The combining of alcohol and energy drinks is popular for some of the dance-club set, such as the vodka and Red Bull combination.

Are these energy drinks risky, especially for young people? Some researchers suggest there is evidence the answer is yes.

For some young people, the problem may not be over-consumption of caffeine itself as much as it would be combining caffeine with alcohol. For others, unwanted side-effects of the caffeine in energy drinks may include insomnia, anxiety or the feeling of one's heart beating too quickly or erratically.

Yet caffeine can be used in a healthy and balanced way. It is perhaps the world's most popular stimulant, and in moderate doses, most adults feel that the feelings of pleasure and alertness outweigh any unwanted side-effects.

As of 2012 much remains to be discovered about any benefits and risks associated with energy drinks. Research has yet to catch up with popular culture and consumption habits.

What does caffeine do to the brain and body?

Energy drinks deliver molecules of caffeine through the bloodstream, and there are effects both on the central nervous system and elsewhere. Caffeine is not a naturally occurring chemical produced by the body, but it is similar enough, and might be imagined to be like a new key fitting into an existing lock.

The dense, tree-like neurons in the brain connect to each other over and over again in what are called "synapses". Drugs, alcohol, hormones and other signaling molecules diffuse through the fluids of the brain and come in contact with synapses.

Caffeine, by binding to a molecular structure that chemists call a "receptor", modifies the electrical and chemical signals produced by some of the neurons in the brain.

When caffeine attaches to the receptor, the internal state of the cell is slightly changed. The electrical and chemical output of the cell is altered, and those cells it connects to receive an altered signal. This stimulates the release of the hormone adrenaline, which diffuses and activates still more physiological signals.

When many millions of cells' receptors receive caffeine, and the cells change their electrochemical communications, whole networks are activated in the brain and a flood of adrenaline enters the body.

While psychologists and neuroscientists do not understand how the altered communications in neural networks manifest as changed consciousness, the overall effect is the familiar one to many people: a sense of heightened alertness, energy or less sleepiness.

There are effects of caffeine in energy drinks beyond what happens in the central nervous system. There are receptors affected by caffeine in the peripheral nervous system. The brain, when activated by caffeine, sends pulses to the peripheral nervous system. Heart rate can speed up, blood vessels can constrict, and breathing can change.

This drug, like all drugs should be used responsibly. It should not be a substitute for sleep, and two or three cups of coffee is plenty. Coffee or energy drinks can be enjoyed in moderation, but users should monitor their intake. Problems with insomnia, anxiety or heart palpitations may be a sign that caffeine use should be lessened or cut out altogether.

Does caffeine cause psychological or physiological problems?

People like feeling more alert and energized. Coffee and other caffeine-laden beverages have positive associations for many people. Any consideration of possible negatives effects of this substance should be balanced against the consideration that people derive substantial enjoyment from coffee and energy drinks and feel like they benefit from them.

The effect of caffeine on overall health in general and central nervous system activation in particular is not necessarily positive. Caffeine is associated with insomnia, restlessness, edginess, irritability, and for some palpitations, the highly unpleasant feeling that one's heart is skipping beats, beating quickly or erratically.

Caffeine and alcohol used together present different challenges.

According to the Wall Street Journal, the popular alcohol-based energy drink Sparks originally had caffeine, but after criticism about health risks and legal dangers, manufacturer MillerCoors removed it.

Chad Ressig, Ph.D and colleagues reviewed studies indicating that drinking a caffeinated energy drink with alcohol compromised how subjects perceived  impairment of their motor coordination, in comparison to only alcohol.

They write in the journal Drug and Alcohol Dependency:

"Thus, when mixing energy drinks and alcohol, users may not feel the symptoms of alcohol intoxication. This may increase the potential for alcohol-related injury. Indeed, a recent survey of college students found that in comparison to those who consumed alcohol alone, students who consumed alcohol mixed with energy drinks had a significantly higher prevalence of alcohol-related consequences including: being taken advantage of, or taking advantage of another student sexually, riding in an automobile with a driver under the influence of alcohol, or being hurt or injured."

The authors also looked a whether there are associations between caffeine use and medical conditions:

"Studies in adult twins show that lifetime caffeine intake, caffeine toxicity and caffeine dependence are significantly and positively associated with various psychiatric disorders including major depression, generalized anxiety disorder, panic disorder, antisocial personality disorder, alcohol dependence, and cannabis and cocaine abuse/dependence."

The key word in the above list is associated. This does not mean caused by.

Your coffee drinking coworkers are not on the verge of becoming cocaine addicts because of their three times a day caffeine habit. The probabilities for one situation can change when another condition is present, that's all. A statistical association with something bad such as cocaine use does not tell us very much at all about any individual's chances.


Caffeine-laden energy drinks are growing in popularity but may present risks.  Caffeine is a potent stimulant and has physiological effects in both the central nervous system and elsewhere.

There is some evidence that energy drinks mixed with alcohol can mask the awareness of alcohol intoxication, which can present serious problems. Caffeine should be treated with respect and used with caution.

Many people are able to enjoy coffee or energy drinks safely, but users need to monitor their usage. People with insomnia, anxiety or heart palpitations may be better off cutting back or not using altogether.

Review Date: 
July 12, 2012