Blueberries are rich in flavonoids that possess antioxidant and anti-inflammatory properties, which in rodent models are neuro-protective. The risk of developing dementia is reduced in people habitually consuming high flavonoid intakes, but data from human intervention studies is sparse. We therefore investigated whether 12 weeks of blueberry concentrate supplementation improved cognitive function in healthy elderly via increased brain activation and perfusion. Twenty-six healthy elderly matched for Addenbrooke’s Cognitive Examination score (ACE-III) were block randomised to consume either 30 ml blueberry concentrate (5 female, 7 male, age 67.5±3.0y; BMI, 25.9±3.3kg.m-2; ACE-III, 95±4) providing 12.9 mg.ml-1 anthocyanin or isoenergetic placebo (8 female and 6 male; age 69.0 ±3.3 y; BMI, 27.1±.4.0 kg.m-2, ACE-III, 95±3) once per day for 12 weeks. The study was approved by the local University research ethics committee. Before and after supplementation, participants undertook a computer based battery of cognitive function tests and a numerical Stroop test within a 1.5T MRI scanner while functional magnetic resonance images were continuously acquired. In addition, quantitative resting brain perfusion was determined using an arterial spin labelling (ASL) technique. fMRI data were analysed based on massunivariate testing within the general linear model framework over the whole brain, treating each participant separately and constructing individual maps comparing the differences in response between visits. Group analysis was subsequently undertaken combining the individual responses, with differences between groups identified in regions with an uncorrected p-value < 0.001 and a cluster size threshold of 10 voxels. ASL data were analysed using the Oxford University FSL software library. Working memory (two back test) improved after blueberry versus placebo supplementation (pre-post change in response time: -1.0 ± 2.6 vs 0.4 ± 1.5%, p=0.09; accuracy 3.6 ± 9.0 vs -3.8 ± 9.0 %, p=0.05, mean±SD, unpaired t-test), but there were no significant differences between groups for the other cognitive function tests. The change in Stroop test performance was not different between conditions. However, significant increases in brain activity were observed in response to blueberry supplementation relative to the placebo group within Brodmann areas 4/6/10/21/40/44/45, the precuneus, anterior cingulate, and insula/thalamus (p=0.02), as well as significant improvements in grey matter perfusion in the parietal and occipital lobes (p<0.001). Collectively these data suggest that 12 weeks of supplementation with an anthocyanin rich blueberry concentrate improves active brain areas associated with cognitive function and brain perfusion in healthy elderly participants.