Energy boost in a can: is it as beneficial as it seems?

Consumers who rely on energy drinks for a boost should understand how to dose caffeine because nutrition labels can be misleading, experts say (Photo by Sgt. David Bruce/Camp Atterbury Public Affairs).Experts say consumers who rely on energy drinks for a boost should understand how to dose caffeine because nutrition labels can be misleading. (U.S. Marine Corps graphic)

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NutritionGrabbing an energy drink or two may seem like a good idea when you’re looking for a lift to get you through the day. After all, these drinks are marketed to provide mental and physical stimulation. The energy boost can help temporarily, but Military Health System experts want you to know there’s more to energy drinks than meets the eye.

Patricia Deuster, Ph.D., director of the Consortium for Health and Military Performance at Uniformed Services University of the Health Sciences in Bethesda, Maryland, said energy drinks can be beneficial when consumed properly, but people should understand how to dose caffeine.


“The amount of caffeine varies [between brands],” said Deuster, adding that information on the nutrition labels of energy drinks can be misleading. Other ingredients in energy drinks, such as guarana (Brazilian cocoa), can also contain caffeine, making the true caffeine content higher than the amount listed on the nutrition label.

Some people see performance benefits from caffeine, while others can be hypersensitive to it and have adverse reactions with even small amounts.

“People don’t realize that drinking a couple of energy drinks in a fairly short amount of time, like in one hour, can potentially harm them,” said Deuster. Drinking such high doses of caffeine and sugar in a short amount of time could overstimulate a person’s central nervous system, causing short-term effects like nervousness, shakiness, rapid heart rate, irritability, or sleep issues, said Deuster. More serious side effects include heart palpitations and an increase in blood pressure. Long-term effects of energy drinks are not yet known. Depending on a person’s caffeine tolerance, combining an energy drink with other caffeinated products like soda, tea, and dietary supplements – including pre-workout and weight loss supplements – can also overstimulate the central nervous system.

Maj. Sean Spanbauer, a performance dietitian for U.S. Army Special Operations Command, recommends limiting energy drink consumption to one or two per day, and no more than one in a four-hour period.

“A general rule of thumb is not consuming more than 400 milligrams of caffeine per day,” said Spanbauer, or 200 milligrams every three to four hours. According to OPSS, the most popular energy drinks contains about 80-120 milligrams of caffeine per eight ounce serving, and some contain more than one serving in a can.

“In a deployed environment,” Spanbauer added, “if somebody is sleep deprived and mission critical, there are benefits to caffeine, so I would start with 200 milligrams but do not exceed 600 milligrams in one day.”

A 2010 study by Walter Reed Army Institute of Research found that almost 45 percent of deployed service members drank at least one energy drink per day, and nearly 14 percent drank three or more a day. The long-term effects of consuming energy drinks regularly aren’t known, but in the short term, sleep quality can be impacted. Long-term sleep issues can negatively affect health and disease risks.

“If you consume caffeine habitually, the cognitive boost or physical performance benefit becomes less effective just because your body gets used to it,” said Spanbauer.

Coffee and caffeine gum can provide a quick energy boost for those who aren’t keen on energy drinks. However, getting enough sleep, staying hydrated and eating a healthy diet are essential for maintaining good health and energy in the long run.

“It’s very important to talk about this because it’s a safety issue that affects our service members and their families, their ability to stay healthy and perform the mission, and potentially their long-term health,” said Spanbauer.

To learn more about supplements in dietary drinks, visit the Operation Supplement Safety website, a DoD dietary supplement resource for the military community, leaders, health care providers, and DoD civilians.