Short-Term New Zealand ‘Blackadder’ Blackcurrant Juice Supplementation Improves Learning and Memory in Young Adult Rats

Berryfruit consumption has been shown to improve aspects of cognition in humans, and may protect against age-related cognitive decline via antioxidant mechanisms. This study investigated whether short-term supplementation with New Zealand 'Blackadder' blackcurrant (BC) juice supports spatial learning and memory in healthy young adult Sprague Dawley rats. Male rats (<i>n</i> = 24) received BC juice (<i>n</i> = 12; 5.4 mg/kg polyphenols) or a sugar-matched placebo (<i>n</i> = 12) prior to each daily trial during a four-day Morris Water Maze (MWM) acquisition phase and a probe trial on day five. BC supplementation significantly reduced cumulative distance (<i>p</i> = 0.020) and latency (<i>p</i> = 0.030) to the platform. In the probe trial, the trends showed that BC-supplemented rats spent more time in the platform zone. These improvements corresponded with detectable plasma anthocyanins, and trends toward higher hippocampal superoxide dismutase activity (<i>p</i> = 0.028, <i>p</i>_a = 0.140) and lower circulating corticosterone (<i>p</i> = 0.052, <i>p</i>_a = 0.228) in the BC group. These results suggest that BC phytochemicals may support spatial learning and memory. Mechanisms of effect may occur through specific antioxidant-mediated neuroprotective pathways and/or modulation of aspects of the hypothalamic-pituitary-adrenal axis.