Plain language summary
Diet is an important lifestyle factor having a considerable impact on cognitive development and healthy brain function across the lifespan. Flavonoids are a class of polyphenols found in abundance in several foods such as berries, tea, cocoa, citrus fruit, and green leafy spices. The aim of this study was to explore the eﬀects of a ﬂavonoid rich berry intervention on cognition and mood in young 20–30 years old adults. The study used a randomized, single blinded, placebo-controlled, parallel group design. Forty participants were recruited for the study which were allocated to 1 of the two groups: mixed berry (n=20) and placebo (n=20). Results indicate that ﬂavonoid-rich interventions are most eﬀective where cognitive demand is high. The participants in the berry group showed signiﬁcantly faster response time at the 6 h time point whilst performing the Switching Task, and there was no decrease in accuracy performance. Authors conclude that acute intervention with ﬂavonoid rich berries facilities effectively maintain or improve cognitive performance.
undefined: Research with young adults has previously indicated flavonoid-rich berry interventions facilitate improved executive function (EF) and positive affect 20 min-2 h post-dosing. There has been little consideration of the impact of a berry intervention over a working day and interventions have also tended to consider only a single berry type. This study investigated the temporal profile of EF and mood changes over a 6 h period following a mixed-berry intervention. We hypothesized berry-related benefits would be most evident when participants were cognitively compromised on demanding elements of the task or during periods of fatigue. The study employed a single-blind, randomized, placebo controlled, between-subjects design. Forty participants aged 20-30 years consumed a 400 mL smoothie containing equal blueberry, strawberry, raspberry, and blackberry ( = 20) or matched placebo ( = 20). Mood was assessed using the Positive and Negative Affect Schedule; EF was tested using the Modified Attention Network (MANT) and Task Switching (TST) Tasks. Testing commenced at baseline then 2, 4 and 6 h post-dosing. As expected, following placebo intervention, performance decreased across the day as participants became cognitively fatigued. However, following berry intervention, participants maintained accuracy on both cognitive tasks up to and including 6 h, and demonstrated quicker response times on the MANT at 2 and 4 h, and TST at 6 h. This study demonstrates the efficacy of flavonoid rich berries in maintaining or improving cognitive performance across the 6 h day.