Fatigue is defined as a decline in the ability and efficiency of mental and/or physical activities caused by excessive or demanding mental and/or physical labour, or illness. The sensation of being fatigued often manifests as a peculiar sense of discomfort, a desire to rest, and a decline in motivation. Impaired cognitive function from mental fatigue is one of the most significant causes of accidents in modern society.1
Mental fatigue has also been reported to affect physical performance, with individuals participating in an endurance task perceiving higher than normal exertion when they were mentally fatigued.2 Perceived exertion is defined as the conscious sensation of how hard, heavy, and strenuous a physical task is.
In search of a natural and simple method to relieve fatigue, interest in research involving common foods and herbs as anti-fatigue agents have blossomed in food science. Chicken essence, which is widely taken in Asian countries as a traditional remedy, was studied for its traditionally known properties to attenuate physical and mental fatigue. It is produced by a process of water extraction from chicken meat for several hours under high temperature. It consists mainly of proteins, amino acids, and peptides such as carnosine and anserine.
In a study published in 2013, 20 healthy male volunteers were divided into 2 groups, a group was given chicken essence while the other group was only given a placebo. The participants consumed either 1 bottle of essence of chicken or placebo twice a day, after breakfast and dinner, for 4 weeks.3
Experiments evaluating their cognitive performances were conducted before, 1 week later and 4 weeks after consuming the test products. On each experimental day, the participants underwent fatigue-inducing and rest sessions, with evaluations just before and after these sessions. For evaluation, they performed cognitive task trials for 9 minutes and rated their subjective level of fatigue.
Study results indicated that daily oral administration of chicken essence improved recovery from mental fatigue. This was seen by the shorter reaction time in the task involved as compared with the group taking the placebo.3
A similar study involving subjects that were given a week’s consumption of chicken essence also reported improvement in task performance. Measurements were done to evaluate the metabolism of stress-related substances in the blood of the participants and results indicated an increased clearance of cortisol from the blood. This demontrates that chicken essence may not only help recovery from mental fatigue, but also the stress induced from prolonged mental loads.4
The benefits of chicken essence may be attributable to its composition as amino acids in food act as building blocks for the synthesis of cerebral neurotransmitters and hence affect the concentration of neurotransmitters in the brain.
1 Ishii A, Tanaka M, Watanabe Y. Neural mechanisms of mental fatigue. Rev Neurosci. 2014;0(0). doi:10.1515/revneuro-2014-0028
2 Van Cutsem J, Marcora S, De Pauw K, Bailey S, Meeusen R, Roelands B. The Effects of Mental Fatigue on Physical Performance: A Systematic Review. Sports Medicine. 2017;47(8):1569-1588. doi:10.1007/s40279-016-0672-0
3 Yamano E, Watanabe Y, Tanaka M, Ishii A, Tsuruoka N, Abe K. Effects of chicken essence on recovery from mental fatigue in healthy males. Medical Science Monitor. 2013;19:540-547. doi:10.12659/msm.883971
4 Nagai H, Harada M, Nakagawa M et al. Effects of Chicken Extract on the Recovery from Fatigue Caused by Mental Workload. APPLIED HUMAN SCIENCE Journal of Physiological Anthropology. 1996;15(6):281-286. doi:10.2114/jpa.15.281