Enhanced neural activation with blueberry supplementation in mild cognitive impairment

Abstract

Objectives: Preclinical studies have shown that blueberry supplementation can improve cognitive performance and neuronal function in aged animals and have identified associations between anthocyanins and such benefits. Preliminary human trials also suggest cognitive improvement in older adults, although direct evidence of enhancement of brain function has not been demonstrated. In this study, we investigated the effect of blueberry supplementation on regional brain activation in older adults at risk for dementia. Methods: In a randomized, double-blind, placebo-controlled trial we performed pre- and post-intervention functional magnetic resonance imaging during a working memory task to assess the effect of blueberry supplementation on blood oxygen level-dependent (BOLD) signal in older adults with mild cognitive impairment, a risk condition for dementia. Results: Following daily supplementation for 16 weeks, blueberry-treated participants exhibited increased BOLD activation in the left pre-central gyrus, left middle frontal gyrus, and left inferior parietal lobe during working memory load conditions (corrected p < 0.01). There was no clear indication of working memory enhancement associated with blueberry supplementation. Diet records indicated no between-group difference in anthocyanin consumption external to the intervention. Discussion: These data demonstrate, for the first time, enhanced neuronal response during working memory challenge in blueberry-treated older adults with cognitive decline and are consistent with prior trials showing neurocognitive benefit with blueberry supplementation in this at-risk population.

Acute effects of flavonoid-rich blueberry on cognitive and vascular function in healthy older adults

“…Whilst there was no significant effect of the intervention for the other cognitive tasks in the test battery, studies such as that of Boespflug et al [37] have demonstrated physiological effects of flavonoids on the brain in older adults with mild cognitive impairment, in the absence of a behavioural effect for a specific cognitive task, which could explain the non-significant behavioural findings for some of the tasks in the current study. In addition, Igwe et al [38] supplemented younger and older adults with anthocyanin-rich plum juice and found benefits to vascular parameters such as reduced blood pressure, but no cognitive effects.…”

“…Benefits could be due to the interaction of berry-derived flavonoids with cell signalling pathways associated with cognitive performance and helping to maintain healthy cerebrovascular function. Initial evidence from human intervention trials of flavonoid supplementation in this population [6-36-58] as well as individuals with mild cognitive impairment [22,[23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] is promising. However, further research combining the latest brain imaging techniques with biomarkers of cognitive and vascular function, bioavailability of flavonoid metabolites and behavioural testing, would be valuable in improving our understanding of the possible mechanisms through which flavonoid-rich foods may have the potential to promote healthy cognitive ageing by slowing age-related cognitive decline and the onset of neurodegenerative disease.…”

The effect of cognitive demand on performance of an executive function task following wild blueberry supplementation in 7 to 10 years old children

“…Additionally, fMRI studies have found that, following chronic blueberry interventions, aging adults have shown increased BOLD activation of the ACC and frontal areas during performance of an n-back task, 17 and also the left middle frontal gyrus during a Stroop task. 25 Interestingly the increased activation did not lead to improved performance for the Stroop, a similar executive function response interference task to the MANT, however in a recent chronic blueberry intervention with aging adults Miller et al 26 found improvements in executive function tasks which were primarily reliant on the frontal region of the brain and were also considered to be the most challenging in the battery employed. These findings give further credence to the proposal that, even though a cognitive domain, such as executive function, may be responsive to flavonoid intervention and physiological effects may be apparent, the intervention may not show beneficial behavioural changes unless the task is sufficiently sensitive as found by Miller et al 26 and also in our current study.…”

“…Indeed, neuroimaging studies indicate differences in brain activation following flavonoid interventions even when clear behavioural differences have not been found. 17,[23][24][25] Furthermore, Scholey et al 16 found cocoa flavanol related improved executive function effects in young adults when employing a sustained mental effort battery designed to reduce ceiling effects, and, in a chronic anthocyanin rich blueberry intervention with older adults, Miller et al 26 noted that, from a wide battery of cognitive tests treatment related improvements were found on the more challenging executive function tasks.…”

Blueberry Supplementation Mitigates Altered Brain Plasticity and Behavior after Traumatic Brain Injury in Rats

“…This information together with results of the shorter latencies strongly suggest that BB supplementation protects TBI animals from a loss in spatial learning performance. In this regard, recent functional neuroimaging study in humans has established a connection between BB intake and cognitive function . Further, in the EPM test, rats exposed to TBI showed a tendency to reduce time spent in the open arms, which encompasses with clinical reports that psychiatric disorders are often observed in TBI patients .…”