Despite evidence from the animal literature on the benefits of flavonoids on cognition, research with human subjects is limited, particularly with regard to flavonoid-rich blueberries. This research investigated the acute effects of a blueberry beverage (containing - 579mg of flavonoids) on cognition, by conducting randomised controlled cross-over intervention studies with healthy younger (N=19) and older (N=IS) adults. Cognition was measured at baseline, two and five hours post drink. Vascular reactivity and brain-derived neurotrophic factor (BDNF) were also measured, one hour post drink. A magnetic resonance imaging (MRI) study was conducted to determine whether the blueberry drink would lead to increased cerebral blood flow (CBF). Univariate statistical analysis revealed improvement in updating ability in the younger adults and immediate word recognition in the older group, following the blueberry compared to control drink, whereas susceptibility to priming in the older adults was reduced. However, for the majority of the univariate analyses, there was no significant effect of the intervention, which was also true following multivariate analysis of the cognitive measures. In both groups, whilst there was no effect of the intervention on vascular reactivity, BDNF levels were higher following the blueberry compared to control drink. Whilst results of the MRI study revealed no effect of the intervention on whole brain or gray matter CBF, there was increased CBF in different regions of the occipital cortex post consumption of the drinks, however more interestingly, there was a greater increase in CBF in areas of the precentral and middle frontal gyrus (frontal lobe) as well as the angular gyrus (parietal lobe) following the blueberry compared to control drink. In conclusion, acute blueberry supplementation led to improvement in some cognitive abilities, possibly due to the impact of flavonoids on cell signalling pathways (e.g. those involving BDNF), in addition to vasodilatory properties and subsequent CBF increases.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:607157 |
| Date | January 2012 |
| Creators | Dodd, Georgina Frances |
| Publisher | University of Reading |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
Page generated in 0.0026 seconds