Health & Wellness: The Energy Drink Issue

Oct. 1, 2017
Sara Jahnke and Chris Kaipust share the pros and cons of consuming energy drinks.

Long days, a lot of runs, sleepless nights, several shifts in a row. It’s not surprising that coffee is a staple at firehouses across the country. Increasingly, firefighters also are consuming energy drinks to get the extra boost they need to make it through their shifts. 

While sales of soda are sliding due to health concerns and a struggling economy, the rate of sales for energy drinks are steadily growing. Redbull and Monster have long dominated the energy drink market and sell a combined $8 billion worth of product annually.1 

Impact of caffeine

The topic of energy drinks has been receiving some increased scrutiny in the fire service after the June 10, 2017, collapse of a Kansas City firefighter during a routine training on a warm day. He ended up in a week-long coma due to heat stroke. According to his cardiologist, the firefighter’s use of energy drinks may have contributed to the severity of the event due to the diuretic effect of caffeine contained in the drinks.

Unfortunately, the incident was not an isolated event. A report from the Substance Abuse and Mental Health Services Administration (SAMHSA) found rates of emergency room visits due to energy drinks doubling between 2007 and 2011.2

But it remains unclear how dangerous energy drinks are, what constitutes an appropriate or safe level of use, and whether they are something that firefighters can or should use on a regular basis.

An 8-ounce cup of brewed coffee hosts about 95 mg of caffeine. While a 12-oz. Redbull or 16-oz. Monster have similar amounts of caffeine to brewed coffee, others can have twice that amount, and energy “shots” can host up to three times the caffeine of coffee.

There is no exact universal amount of caffeine that is appropriate for all people. The amount of caffeine and the effect it has on any given person varies by personal factors, such as BMI, medication use, genetics, age, medical disorders, and how much caffeine the person typically consumes. Bodies can build a tolerance to caffeine, requiring more of it for the same effect over time.

As with any drug, caffeine also has addictive properties, and stopping can lead to withdrawal. According to a report by Dr. Catherine Striley3 in the Journal of Caffeine Research, 35 percent of people meet the diagnostic criteria for caffeine dependence. Withdrawal can lead to headaches, aches and pains, depression and irritability. 

The level of caffeine in energy drinks may not be the only concern. Several other ingredients common to energy drinks or shots have other energy-enhancing ingredients— taurine, guarana, yerba, and green tree extract—that mimic the effects of caffeine.   

According to a report by Dr. Fahad Ali published in the journal Postgraduate Medicine,4 the most common negative effects of energy drinks are cardiovascular and neurological. Of particular concern in his review of the literature was the interaction of ingredients. While the ingredients have all been found to be safe on their own, research on the combinations is limited.

A few literature reviews have been conducted on the health effects of energy drinks, examining results across individual studies to form conclusions on the science thus far. Many of the beneficial and negative physiologic, cognitive, behavioral and performance effects of energy drinks likely come from the caffeine and taurine content.  

The upside

There are benefits associated with energy drinks as well. Energy drinks have been associated with increased cognitive and physical performance.5 Research examining the effect of energy drinks on cognition has found increased memory performance, improved performance on information processing tasks, improved performance on six composite cognitive function measures, and increased alertness. There was also evidence of improvement on subjective measures, such as anxiety and levels of stress. 

The effects of energy drinks on physical performance have also been positive, likely due to taurine.6 Energy drinks have been found to improve physical performance in muscle strength and endurance, endurance exercise tests, jumping, and sport-specific movements, but not sprinting. 

The downside

While there are some researched benefits of energy drinks, there also have been a number of negative effects noted.5 Multiple self-report surveys and a randomized placebo-controlled clinical trial found insomnia, nervousness, increased pulse rate/palpitations, and activeness to be the most common side effects.

Energy drinks have been shown to have negative effects on the cardiovascular system.5 Among normal healthy individuals, energy drinks have been shown to significantly increase mean 24-hour systolic, diastolic and mean arterial blood pressure when compared to a simple caffeine solution with similar levels of caffeine as a cup of coffee. Thus, energy drink consumption is not recommended for those with high blood pressure. Myocardial contractility, or the innate ability of the heart to contract, can be also increased by consumption of energy drinks containing both caffeine and taurine, which may be dangerous for those with cardiac arrhythmia. 

Looking at 17 case studies of acute cardiovascular events associated with energy drink consumption, only one case had any sign of previous cardiac disease, and there were no predisposing cardiac abnormalities in most cases.5 The high caffeine content of energy drinks, and consumption of multiple drinks, are likely associated with the cardiovascular complications in these cases.   

Energy drinks and alcohol

The FDA announced in November 2010 that caffeine was an unsafe food additive to alcoholic beverages, which eliminated the pre-mixed alcoholic energy drink market.5 However, drinks such as “Red Bull Vodkas” are still sold and widely consumed at bars. Mixing energy drinks with alcohol has been associated with binge drinking, risky sexual behavior, and driving while intoxicated. Another concern with mixing energy drinks and alcohol is the possibility the caffeine content from the energy drinks will keep the individual awake longer, extending the drinking session and therefore encouraging intoxication. 

More research is needed

Self-report and clinical studies have shown negative health effects of energy drinks, but there is still much more that needs to be answered. One of the main concerns about energy beverages revolves around the lack of research on the interaction of the ingredients. While many of the ingredients in energy beverages are generally recognized as safe on their own within a certain range of doses, the safety of the effect of these ingredients together has not been examined in depth, especially in the long term.7 Further, many consume more than the recommended one can serving per day, or may drink other caffeinated beverages during the day.  

Another concern is the lack of regulation around energy beverages. The United States has one of the least stringent regulatory systems for energy beverages.7 Energy beverages are classified as dietary supplements, which doesn’t require the strict regulation food products endure. For example, energy beverage companies are only required to list the ingredients, not the amount of the ingredient on the label. In 2012, Consumer Reports examined the level of caffeine in 20 popular energy beverages. It found that of the 16 that listed a specific amount of caffeine, five had caffeine levels more than 20 percent of what was listed on the label.8 So an individual may know they are consuming caffeine in their energy drink, but either not know how much is in that drink, or the amount contained differs from the amount reported.

Firefighters and hydration

The firefighting environment poses many challenges to maintaining hydration. Firefighting tasks have been found to be particularly stressful and lead to dehydration.9 The heat stress associated with being in encapsulating gear in a high-heat environment is the perfect environment for dehydration.

A study by Gavin Horn and colleagues in the journal Prehospital Emergency Care suggests that firefighters often are dehydrated even when they arrive on the fire ground or at training.9 Energy drinks in particular, and caffeine in general, work as diuretics, which also can lead to dehydration. Consuming energy drinks and high levels of caffeine without proper water consumption may exacerbate dehydration during firefighting tasks.

What is a firefighter to do?

Given energy drinks are used to combat tiredness, working to avoid extreme tiredness as much as possible is an important step for avoiding needing energy drinks on a regular basis. Sleep hygiene and trying to get as much sleep as you need when you are off duty is as important as getting sleep on duty. For busy stations where you will likely be awake during the night, try to get a nap during the day. Drinking caffeine immediately before taking a short nap might be the best way to combat fatigue.

Pay attention to the quality of the sleep you are getting. More than 80 percent of firefighters report symptoms of sleep disorders, but most have not received a diagnosis or treatment.10 If you snore or have other symptoms of sleep disorders, discuss them with your doctor. 

Do not count energy drinks toward your hydration goal for the day. Trying to hydrate yourself with water once you are on shift is too late to combat dehydration. Make water your staple beverage and be sure to drink up (the water that is) the day before you go on shift. If you are drinking a lot of caffeine or energy drinks, you may need to up your water intake even more. 

As with most things, moderation is key. What is most important for the fire service is being responsible consumers of what they are taking in to their bodies. While there is no specific rule for safe caffeine consumption, 400 mg a day is typically recommended as safe. That amount is approximately 4 cups of brewed coffee, 10 sodas or just 2 energy shots—or one depending on the type of shot. For those who use energy drinks to stay awake and alert, it is important to know how much caffeine and sugar is being consumed and titrate both the consumption of energy drinks and other caffeine containing products as appropriate. 


1. Top Selling Energy Drink Brands. March 14, 2016

2. Substance Abuse and Mental Health Services Administration, Center for Behavioral Health Statistics and Quality. The DAWN Report: Update on Emergency Department Visists Involving Energy Drinks: A Continuing Public Health Concern. Rockville, MD; 2013.

3. Striley, CLW; Griffiths, RR; Cottler, LB. Evaluating Dependence Criteria for Caffeine. J Caffeine Res. 2011;1(4):219-225. doi:10.1089/jcr.2011.0029.

4. Ali, F; Rehman, H; Babayan, Z; Stapleton, D; Joshi, D-D. Energy drinks and their adverse health effects: A systematic review of the current evidence. Postgrad Med. 2015;127(3):308-322. doi:10.1080/00325481.2015.1001712.

5. ManchesterJulianne, EshelInbal, W M. The Benefits and Risks of Energy Drinks in Young Adults and Military Service Members. Mil Med. July 2017. doi:10.7205/MILMED-D-16-00339.

6. Souza, DB; Del Coso, J; Casonatto, J; Polito, MD. Acute effects of caffeine-containing energy drinks on physical performance: a systematic review and meta-analysis. Eur J Nutr. 2017;56(1):13-27. doi:10.1007/s00394-016-1331-9.

7. Higgins, JP; Tuttle, TD; Higgins, CL. Energy Beverages: Content and Safety. Mayo Clin Proc. 2010;85(11):1033-1041. doi:10.4065/mcp.2010.0381.

8. Caffeine levels in energy drinks - Consumer Reports.

9. Horn, GP; DeBlois, J; Shalmyeva, I; Smith, DL. Quantifying dehydration in the fire service using field methods and novel devices. Prehospital Emerg Care Off J Natl Assoc EMS Physicians Natl Assoc State EMS Dir. 2012;16(3):347-355. doi:10.3109/10903127.2012.664243.

10. Barger, LK; Rajaratnam, SMW; Wang, W, et al. Common sleep disorders increase risk of motor vehicle crashes and adverse health outcomes in firefighters. J Clin Sleep Med JCSM Off Publ Am Acad Sleep Med. 2015;11(3):233-240. doi:10.5664/jcsm.4534.

About the Author

Sara Jahnke

Dr. Sara Jahnke is the director of the Center for Fire, Rescue & EMS Health Research at the National Development and Research Institutes. She completed her doctorate in psychology with a health emphasis at the University of Missouri–Kansas City and earned the American Heart Association’s Fellowship on the Epidemiology and Prevention of Cardiovascular Disease. Jahnke served as the principal investigator of several large-scale studies of the health and readiness of the U.S. fire service. She serves as a consultant to fire service organizations, including the National Volunteer Fire Council and the National Fallen Firefighters Foundation.

About the Author

Christopher Kaipust

Christopher Kaipust is a National Institute for Occupational Safety and Health (NIOSH) Doctoral Occupational Epidemiology Trainee at the Southwest Center for Occupational and Environmental Health at University of Texas School of Public Health. Kaipust received his master’s of public health in epidemiology from the University of Texas School of Public Health, with a focus on nutritional and chronic disease epidemiology. He is currently finishing his PhD in epidemiology with a focus on occupational health. His primary research interest is on the total worker health of firefighters, or the interaction between personal health and occupational health and safety.

Voice Your Opinion!

To join the conversation, and become an exclusive member of Firehouse, create an account today!