SILVER SPRING, MD–High consumption of energy drinks could be leading to sleep problems for deployed troops, potentially impairing military performance, according to a new study from the Walter Reed Army Institute of Research.
Analysis of data gathered in Afghanistan during the summer of 2010 indicated that 44.8% of deployed servicemembers—across all ranks and ages–consumed at least one energy drink daily, with 13.9% drinking three or more a day.
Those who drank three or more energy drinks a day were significantly more likely to report sleeping less than four hours a night on average and to report sleep disruption related to stress and illness than those consuming two drinks or fewer. Heavy users of energy drinks also reported that they were more likely to fall asleep during briefings or on guard duty.
The hours of sleep were low even for the deployed environment, where half of servicemembers said in a survey that they sleep less than five hours a night.
“Servicemembers should be educated regarding the potential adverse effects of excessive energy drink consumption on sleep and mission performance and should be encouraged to moderate their energy drink consumption in combat environments,” according to the authors of the report, published this week in the national Center for Disease Control and Preventions’ (Morbidity and Mortality Weekly Report (MMWR).
While energy drink use is high among adolescents and young adults in the civilian population—more than half consume at least one drink a month with about 6% using them daily—the rate among active-duty military members was much higher.
“This might reflect the unique and extreme demands of a combat deployment and the widespread availability of energy drinks in the combat environment (e.g., free distribution in dining facilities and available for purchase in convenience stores),” the report added.
The authors cautioned that causality could not be ascertained from the cross-sectional study but suggested that the relationship between energy drink consumption and sleep disruption is in line with civilian studies. They noted inadequate sleep’s deleterious effect on the body and questioned whether excessive energy drink consumption could contribute to poor overall health.
In discussing the study’s limitations, the researchers noted that it is “unclear whether servicemembers with sleep problems used more energy drinks to stay alert, or if heavy use of energy drinks led to sleep disruptions; published studies suggest a cyclical combination of both.”
Another limitation was the lack of evidence on exactly how much caffeine was being ingested. Not only does caffeine content in energy drinks vary greatly but consumption of other caffeinated beverages such as coffee and soft drinks was not measured by the survey. The report did point out, however, that some cans of energy drinks have as much caffeine as three cups of coffee.
“The widespread use of energy drinks across demographics and its association at high doses with sleep problems and work impairment, coupled with known associations between caffeine and sleep problems and sleepiness in the general population support the need to educate servicemembers about moderating consumption of energy drinks,” the authors wrote, noting that military personnel who used energy drinks in moderation, i.e. two or fewer a day, had no more sleep problems than those who did not drink the beverages.
For the study, 1,249 servicemembers—all male– were surveyed using a cluster sample of randomly selected U.S. Army and Marine combat platoons deployed to Afghanistan. Of those surveyed, 1,000 consented to have their data used for research purposes and 988 answered the following question: “How many energy drinks (e.g., Monster, Red Bull, 5-Hour Energy) do you use per day?”
Respondents also were questioned about their use of sleep medication, average number of hours of sleep per day, concerns regarding lack of sleep, disruptions to sleep, and work impairment associated with sleepiness.
Part of the problem in educating energy drink users, according to the report, is that the beverages are fairly new to market, generally unregulated and lack warning labels.
“Marketing of these types of drinks as energy boosters, together with their availability in the combat environment, makes it easy for service members to consume them in large volumes,” the authors wrote.