Caffeine intake in the form of energy drinks is common practice in the military. A recent study from the Centers for Disease Control and Prevention found that 45% of service members consume energy drinks on a daily basis. Yet, federal law does not require that these drinks list caffeine content on the label.
In the study, which was funded by the Department of Defense and part of an ongoing collaboration to promote dietary supplement safety, NSF International, Harvard Medical School and the Uniformed Services University examined 31 of the most popular dietary supplements sold as capsules on military installations (no drinks or gels were included in the analysis). Samples from the supplements were analyzed for caffeine content per serving and compared against what was listed on the product label. The researchers found that the caffeine content in supplements was not only inconsistent, it was also often inaccurate.
Of the 20 dietary supplement products that listed caffeine on the label, six products (30%) failed to state the amount of caffeine on the label. In comparison to an average 8-oz. cup of coffee containing 100 mg of caffeine, those products contained high amounts of caffeine, ranging from 210 to 310 mg per serving.
In addition, five of the 20 products (25%) were inaccurately labeled containing a dose of caffeine that was at least 10% more or less than the labeled amount. What’s more, only nine of the products (45%) listed an accurate amount of caffeine on the label.
The NSF International/Harvard/USU study also looked at herbal ingredients in dietary supplements that are known to naturally contain caffeine to understand if the caffeine content was properly disclosed on the supplement label. Findings revealed that 11 supplements listed an herbal ingredient that naturally includes caffeine but did not list “caffeine” on the label.
“It is common for military personnel and general consumers to drink other caffeinated beverages, like coffee, soda and energy drinks, throughout the day,” said Ed Wyszumiala, general manager of NSF International's Dietary Supplement Certification Programs. “Without accurately knowing the caffeine content in a supplement, people run the risk of consuming unhealthy levels of caffeine.”
“Caffeine at low doses (100-300 mg) is ergogenic and has a body of literature supporting its beneficial effect on vigilance, wakefulness and physical performance,” commented Patricia Deuster, PhD, MPH, FACSM, professor and scientific director for the Consortium for Health and Military Performance, Department of Military and Emergency Medicine, Uniformed Services University. “The military has a caffeine chewing gum that is provided in the rations. Many studies have compared caffeine to drugs in terms of keeping someone awake and when dosed properly it is very effective.”
Dr. Deister went on to explain that caffeine at high doses poses the danger of degrading performance in terms of rapid heart rate, anxiety, sleeplessness and the jitters. “The maximum recommended dose at one time would be 600 mg—and that would be for a large person,” she said. “One to three mg/kg is the preferred dose for performance enhancement.”
Mr. Wyszumiala asserted that the study highlighted the inconsistent labeling practices of many dietary supplement manufacturers. “Studies such as this one highlight the need for more testing of supplements,” he said, and he pointed to NSF International’s American National Standard for testing dietary supplements as a resource that consumers can use to look for products that are tested and certified to ensure what’s on the label matches what’s in the bottle and there are no unacceptable levels of contaminants.
“Consumers have the right to have access to accurate information about the quantity of caffeine in dietary supplements so they can make educated decisions when purchasing these products,” concluded Mr. Wyszumiala.