Effect of carbohydrate administration on recovery from stress-induced deficits in cognitive function: A double-blind, placebo-controlled study of soldiers exposed to survival school stress

Objective: The goal of this project was to evaluate the effects of energy supplementation, as liquid carbohydrate (CHO), on facilitating recovery of cognitive function in soldiers who have been exposed to sustained psychological and physical stress during Survival School Training. Project Design: A double-blind, placebo-controlled design was used. Healthy, male volunteers attending survival training were recruited for participation in the study. At the conclusion of the mock captivity phase of survival training and before a recovery night of sleep, subjects participated in cognitive testing. After this, subjects were randomly assigned to one of three treatment groups. Subjects received either a 6% CHO (35.1 kJ/kg), 12% CHO (70.2 kJ/kg), or placebo beverage in four isovolemic doses. In the morning of the following day, all subjects participated in a second assessment of cognitive functioning. Results: Compared to subjects who received placebo, those who received supplemental CHO beverages exhibited significantly improved performance on a complex cognitive task (i.e., Stroop Test) involving concentration effectiveness associated with selective attention and response inhibition. No differences were observed on a variety of cognitive tasks of lesser complexity. Discussion: These data suggest nutritional interventions enhance the rapid recovery of complex cognitive functions impaired by exposure to significant or sustained stressful conditions. In addition to enhancing speed of recovery of function between operational intervals, the current data suggest that dietary supplement strategies may hold promise for enhancing field performance and a capacity to assist in sustaining operations by military personnel over time.