Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2019 Nov 6;11(11):2685.
doi: 10.3390/nu11112685.

Flavonoid-Rich Mixed Berries Maintain and Improve Cognitive Function Over a 6 H Period in Young Healthy Adults

Affiliations
Free PMC article
Randomized Controlled Trial

Flavonoid-Rich Mixed Berries Maintain and Improve Cognitive Function Over a 6 H Period in Young Healthy Adults

Adrian R Whyte et al. Nutrients. .
Free PMC article

Abstract

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 (n = 20) or matched placebo (n = 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.

Keywords: berry; blackberry; blueberry; cognition; executive function; flavonoid; mood; polyphenol; raspberry; strawberry.

Conflict of interest statement

The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Figures

Figure 1
Figure 1
Intervention allocation and participant numbers throughout study.
Figure 2
Figure 2
Time line of procedure and task order on intervention days.
Figure 3
Figure 3
(a) Mean correct responses (±SE of the mean) as a function of intervention and session, showing a significant reduction in accuracy for placebo at 6 h in comparison to 2 and 4 h and significantly better performance in the berry condition in comparison to placebo at 6 h. (b) Mean correct incongruent trial responses (±SE of the mean) as a function of intervention and session showing a significant reduction in accuracy for placebo at 6 h in comparison to 2 and 4 h and significantly better performance in the berry condition in comparison to placebo at 6 h. Baseline performance, included as a covariate in the analysis, is shown on both graphs separated by the dotted line. # p < 0.01, † p < 0.001.
Figure 4
Figure 4
Reaction time (± SE of the mean) as a function of intervention and session, showing significantly faster berry performance at 2 and 4 h in comparison to the placebo and a significantly faster berry performance between 2 and 4 h. Note there was a trend towards significance at 6 h for faster berry performance in comparison to the placebo and a trend for faster placebo performance between 2 and 4 h. Baseline performance, included as a covariate in the analysis, is shown separated by the dotted line. + p < 0.1, * p < 0.05, # p < 0.01.
Figure 5
Figure 5
(a) Mean correct responses (±SE of the mean) as a function of intervention and session. (b) Mean correct responses (±SE of the mean) as a function of intervention and switch trial showing a significant switch cost between S0 and S1, S2, and S3 for placebo and a significant switch cost only between S0 and S3 for berry. Baseline performance, included as a covariate in the analysis, is shown on graph A separated by the dotted line. + p < 0.1, * p < 0.05, # p < 0.01.
Figure 6
Figure 6
Reaction time (±SE of the mean) as a function of intervention and session, showing significantly faster performance at 6 h in comparison to 2 and 4 h for the berry intervention. Baseline performance, included as a covariate in the analysis, is shown separated by the dotted line. † p < 0.001.
Figure 7
Figure 7
(a) Positive affect scores (±SE of the mean) as a function of intervention and session, showing a significant reduction at 6 h in comparison to 4 h for the placebo intervention. (b) Positive affect scores (±SE of the mean) as a function of intervention and session showing no difference between interventions at any time points.

Similar articles

See all similar articles

References

    1. Devore E.E., Kang J.H., Breteler M.M.B., Grodstein F. Dietary intakes of berries and flavonoids in relation to cognitive decline. Ann. Neurol. 2012;72:135–143. doi: 10.1002/ana.23594. - DOI - PMC - PubMed
    1. Letenneur L., Proust-Lima C., Le Gouge A., Dartigues J., Barberger-Gateau P. Flavonoid Intake and Cognitive Decline over a 10-Year Period. Am. J. Epidemiol. 2007;165:1364–1371. doi: 10.1093/aje/kwm036. - DOI - PubMed
    1. Beking K., Vieira A. Flavonoid intake and disability-adjusted life years due to Alzheimer’s and related dementias: A population-based study involving twenty-three developed countries. Public Health Nutr. 2010;13:1403–1409. doi: 10.1017/S1368980009992990. - DOI - PubMed
    1. Lamport D.J., Dye L., Wightman J.D., Lawton C.L. The effects of flavonoid and other polyphenol consumption on cognitive performance: A systematic research review of human experimental and epidemiological studies. Nutr. Aging. 2012;1:5–25.
    1. Bell L., Lamport D.J., Butler L.T., Williams C.M. A Review of the Cognitive Effects Observed in Humans Following Acute Supplementation with Flavonoids, and Their Associated Mechanisms of Action. Nutrients. 2015;7:10290–10306. doi: 10.3390/nu7125538. - DOI - PMC - PubMed

Publication types

Feedback