FOR IMMEDIATE RELEASE
CAFFEINE HELPS KEEP SOLDIERS VIGILANT AND ON TASK
Also helps Navy SEALS get through “Hell Week” training
New York, NY – October 21, 2004 – Studies on the use of caffeine in the military concluded that it is beneficial for the soldier engaged in long boring tasks, such as guard duty as well in stressful combat-like conditions.
Dr. Harris R. Lieberman discussed the research today at
a symposium for science writers, Coffee and Your Health:
Surprising Findings, held at the New York Academy of
Sciences.. Dr. Lieberman is a research psychologist in the
Military Nutrition Division of the U.S. Army Research Institute of
Environmental Medicine (USARIEM) in Natick, MA. A member of the
civilian research staff, he is an internationally recognized expert
in the area of nutrition and behavior.
He told the science writers that caffeine is a behaviorally active food constituent that is naturally present in many common foods. He described caffeine, a methylated xanthine-1,3,7-trimethyxanthine, as a component of foods consumed throughout the world.
Found in varying amounts, caffeine is present in coffee at 65->110
mg per cup, tea at 40-60 mg per cup, and cola and other soft drinks
at about 40 mg per serving.
Dr. Lieberman explained: “The Committee on Military Nutrition Research recently reviewed the use of caffeine in military operations, and concluded that 100-600 mg can maintain cognitive performance. This is especially evident in situations of sleep deprivation.” Since vigilance is crucial to the military, it is often the focus of their research. The report established that after caffeine, rested volunteers were consistently more vigilant, and mood improved.
According to Dr. Lieberman, the USARIEM has conducted a number of other studies on the effects of caffeine on both sleep deprived and rested volunteers. In one trial, a marksmanship simulator was used to evaluate military volunteers who were not sleep deprived; results showed that after 200 mg of caffeine the subjects detected their targets faster and just as accurately.
Navy SEAL training is notoriously stressful, particularly during “Hell Week.” Dr. Lieberman told the group: “The stress of Hell Week includes near total sleep deprivation, exposure to cold, continuous and often intense physical activities, and extensive psychological stress. Hell Week appears to come as close to the extraordinary level of the stress of combat as any simulation could.”
In one study, military researchers gave caffeine in doses of 100 mg, 200 mg and 300 mg, or placebo, to volunteers after three days of sleep deprivation. They then took a number of cognitive tests. Results showed that the more caffeine the subjects consumed the less they reported feeling tired and sleepy, and the better they performed on tests of such factors as visual vigilance and choice reaction time. Although the greatest effects of caffeine were seen after one hour, improvement continued for eight hours.
Dr. Lieberman observed, “This study demonstrated that even in the most adverse operational circumstances, moderate doses of caffeine had unequivocal, beneficial effects on cognitive performance. Furthermore, it indicated that the optimal dose of caffeine to employ under such conditions was 200 mg, the equivalent to about two cups of coffee.”
Assuring the science writers that the results of this research reach
beyond the military, Dr. Lieberman said that caffeine might prove
beneficial for civilians performing similar tasks. He cited several
studies demonstrating that caffeine improves simulated driving
performance. He went on to say that the Committee on Military Nutrition Research, an external review panel, recommended that caffeine be used as the “compound of choice for counteracting cognitive deficits during military operations.”
Lieberman, H.R.
Nutrition, Brain Function, and Cognitive Performance. 2003.
Appetite 40(3):245-254