In January 2020 researchers from Japan published the results of their study to assess the effects of matured hop bitter acids on cognition, mental fatigue, and mood state. A total of 60 healthy individuals, aged 45-64 years, with self-awareness cognitive decline were involved in the study. The individuals were divided into two groups and received either orally administered matured hop bitter acids (35 mg/day) or placebo for a 12 weeks period. Cognitive function and mental states were assessed using neuropsychological tests or questionnaires at the beginning of the study and at weeks 6 and 12. Results showed that the change in verbal fluency at week 6 was significantly higher in those receiving the matured hop bitter acids compared with those in the placebo group, whilst the Stroop test score at week 12 was significantly lower. Furthermore, mental fatigue and anxiety at week 12 were significantly improved in those given the matured hop bitter acids.
NB The Stroop test is a demonstration of cognitive interference, ie there is a delay in the reaction time to a task due to a mismatch in stimuli, eg the word “red” is printed in blue ink instead of red ink and when asked to name the colour of the word it takes longer and there are more mistakes due to the colour of the ink not matching the name of the colour.
Fukuda T et al. Effects of Hop Bitter Acids, Bitter Components in Beer, on Cognition in Healthy Adults: A Randomized Controlled Trial. J Agric Food Chem. 2020 Jan 8;68(1):206-212.