Daily consumption of essence of chicken (EC) improves cognitive function, according to a large-scale study published recently in Nutritional Neuroscience. The study results clarify the specific nature of EC’s cognitive enhancement effect – EC improves working memory, a cognitive function vital for adults to hold and process information better in their daily lives, and with growing evidence that working memory is a powerful predictor of academic success.
In the largest meta-analysis study to date, Kim Jung Eun, PhD, of the National University of Singapore, and colleagues, collected data from all previously published clinical trials of EC on its cognitive enhancement effects. Eight studies published from 2003 to 2018, with a total of 794 human subjects, were included and their results were combined in a meta-analysis. This study included more than twice the number of human subjects compared to the earlier reviews. Due to the larger numbers, conclusions based on multiple EC clinical trials could be drawn for the first time, providing robust evidence on the nature of cognitive enhancement provided by EC.
Results showed that daily consumption of EC improved cognition, particularly the mental processing aspects of working memory. Five out of the eight qualified studies focused specifically on the working memory domain. In this analysis, EC showed statistically significant working memory improvement effects, (standardised mean difference: 0.31, 95% CI: 0.16, 0.46) when data from 661 healthy, young adults (mostly in their 20s or 30s) conducted in four different countries (Malaysia, Taiwan, Thailand and the United Kingdom) were analysed.
The finding that EC improves working memory in a large, diverse healthy adult population is appealing as working memory is linked to common cognitive tasks such as verbal comprehension, information retrieval from long-term memory and reasoning tasks. These are fundamental to intelligence and learning. More interestingly, growing evidence is now describing working memory as a powerful predictor of academic success, even when compared against other well-known indicators such as IQ.
In the included studies, subjects drank either one [70ml] or two bottles [140ml] of EC daily for 7 days to 28 days. Subjects’ cognitive performance were assessed using objective neuropsychological tests, and the differences in scores before and after consumption were compared between EC and placebo groups. Working memory improvement was demonstrated consistently whether studies of one bottle a day or one and two bottles a day were analysed.
Although the current study did not investigate how EC exerts its effect, a previous neuroimaging study has shown that EC specifically activates the dorsolateral prefrontal cortex (DLPFC), the brain region which supports working memory1. Thus, EC could improve working memory via stimulating or increasing mobilisation of resources for DLPFC function. A second potential mechanism may be linked to EC’s cortisol-clearing effect2, which is beneficial to cognition, as higher cortisol (a stress hormone) levels are associated with cognitive impairment.
By improving working memory function, EC can help healthy adults to hold and process information better in their daily lives. Therefore, daily EC consumption could serve as an excellent strategy to enhance working memory and the overall quality of cognitive performance to support our highly competitive society today.
Darel Wee Kiat Toh, Chun Hong Wong, Johnson Fam & Jung Eun Kim (2019): Daily consumption of essence of chicken improves cognitive function: a systematically searched meta-analysis of randomized controlled trials, Nutritional Neuroscience, DOI: https://doi.org/10.1080/1028415X.2019.1619984.
1 Konagai C, Watanabe H, Abe K, Tsuruoka N, Koga Y. Effects of essence of chicken on cognitive brain function: A near-infrared spectroscopy study. Biosci Biotechnol Biochem. 2013; 77(1): 178–81
2 Benton D, Young HA. The effect of chicken extract on cognition and mood: A randomized controlled trial. Curr Top Nutraceuticals Res. 2015; 13(2): 61–70