A randomised controlled trial to investigate the cognitive, mood and metabolic effects of acute oyster mushroom intervention in older adults (OYSACO)

Authors: CHA, SARA - University Of Reading; BELL, LYNNE - University Of Reading; Shukitt-Hale, Barbara; WILLIAMS, CLAIRE - University Of Reading

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/21/2023
Publication Date: 9/19/2023
Citation: Cha, S., Bell, L., Shukitt Hale, B., Williams, C. 2023. A randomised controlled trial to investigate the cognitive, mood and metabolic effects of acute oyster mushroom intervention in older adults (OYSACO). [Abstract] 4th International Conference on Food Bioactives and Health. Abstract #FBHC23-0131.

Interpretive Summary:

Technical Abstract: Background: The Pleurotus oyster species is a common edible mushroom rich in ergothioneine, a bioactive compound with known neurocognitive benefits. However, no human clinical trial has specifically examined the effects of oyster mushrooms on cognitive function and mood in the immediate postprandial period. Objectives: Using a double-blind, randomised, cross-over design, the objectives of this study were to investigate whether ergothioneine-rich oyster mushrooms induce a) cognitive and mood benefits as well as b) improvements in the markers of metabolism and inflammation, in the acute post-prandial period (6h post-consumption) in healthy older adults. Methods: Healthy adults (n=33) aged 60-80 years old were asked to consume a noodle soup containing the equivalent of 0.5 (OM0.5), 1 (OM1) and 2 (OM2) servings of powdered Pleurotus oyster mushroom and a calorie-matched control soup (OM0), on four separate occasions with one-week washout between test days. Cognitive function and subjective mood were assessed at baseline (-1h, prior to administration of the intervention) and then at 2h, 4h and 6h post-consumption on each test day. The computerised battery included tasks assessing mood (Positive and Negative Affect Schedule, PANAS), episodic memory (Rey’s Auditory Verbal Learning Task, RAVLT), executive function (Task Switching Task, TST), working memory (Corsi Blocks Task, CBT), and psychomotor function (Finger Tapping Task, FTT). Visual Analogue Scales were used to record palatability ratings immediately after consuming each intervention (0h), and to monitor appetite throughout the day (-1h, 0h, 2h, 4h and 6h postprandially). Finally, a serum blood sample was taken at the end of each test day (6h) to examine metabolic and inflammatory markers. Results: All cognitive and mood data were analysed using Linear Mixed Modelling (LMM), with baseline included as a covariate, and Bonferroni-corrected pairwise comparisons. Mood data for positive affect and mental fatigue revealed significant main effects of time, with declining positive affect and increasing fatigue across the day. Subsequent pairwise comparisons revealed significant decline between 2h and 6h only after consuming the control (OM0). However, levels of positive mood and fatigue remained stable throughout the course of the day following consumption of oyster mushrooms (OM0.5, OM1, and OM2). Cognitive findings were mixed. TST data revealed a significant main effect of time and treatment/time interaction for both accuracy and reaction time. Pairwise comparisons revealed higher accuracy at 2h for OM2, and at 4h for OM0.5, compared to OM0. However, for OM0, the accuracy score significantly increased across the day, and mushroom benefits to accuracy performance were no longer apparent at 6h. No reaction time benefits of oyster mushroom were observed compared to OM0. RAVLT delayed recognition data showed a treatment main effect and interaction, but pairwise comparisons between mushroom conditions and the control were found to be non-significant over the 6h period. No significant findings were observed for CBT, FTT, or blood markers. Conclusion: This study has shown a maintenance of positive affect and mental fatigue, up to 6h post-consumption of ergothioneine-rich oyster mushrooms. Acute cognitive and metabolic benefits are less clear and may require a longer period of daily consumption to emerge.