Energy drink consumption by U.S. service members deployed for combat has been linked to sleep problems, according to the most recent Centers for Disease Control and Prevention’s (CDC’s) Morbidity and Mortality Weekly Report. Titled “Energy Drink Consumption and Its Association with Sleep Problems Among U.S. Service Members on a Combat Deployment—Afghanistan, 2010,” the study found that “[s]ervice members drinking three or more energy drinks a day were significantly more likely to report sleeping ≤4 hours a night on average than those consuming two drinks or fewer.” The study also found that those consuming three or more of the beverages each day “were more likely to report sleep disruption related to stress and illness and were more likely to fall asleep during briefings or on guard duty.”

The study involved 1,249 service members “using a cluster sample of randomly selected U.S. Army and Marine combat platoons deployed to Afghanistan.” All were men, and, of those surveyed, 1,000 agreed to the use of their data for research with 988 answering the question, “How many energy drinks (e.g., Monster, Red Bull, 5-Hour Energy) do you use per day?” The researchers recommend educating service members about “the potential adverse effects of excessive energy drink consumption on sleep and mission performance and [encouraging them] to moderate their energy drink consumption in combat environments.”

An editorial accompanying the study highlighted its limitations, including (i) “cause and effect cannot be determined because the data are cross-sectional”; (ii) “the survey did not allow for a true estimate of caffeine intake” and did not account for other caffeine intake; (iii) as asked, the questions about level of use could have “resulted in an underestimate of energy drink use”; (iv) “this study did not control for variables that might have confounded the relationship between energy drink consumption and sleep outcomes (e.g., mental health problems, physical injury, amount of time deployed, or peer group/unit effects)”; and (v) “analyses did not control for sleep medication use, which also can cause daytime sleepiness.”

The editorial notes that military and civilian findings show that more than half of adolescents and young adults drink at least one energy drink per month, and approximately 6 percent consume these beverages every day. In this study, 45 percent of the respondents reported that they consumed one or more of the energy beverages daily. “No differences in energy drink consumption by age or rank were observed, demonstrating the ubiquitous nature of energy drink consumption during deployment.” Because these beverages are “relatively new, generally unregulated, and lack warning labels,” the editorial supports the researchers’ recommendation to tell service members that longterm effects are unknown and high doses could affect their performance and sleep.