Chronic consumption of flavanone-rich orange juice is associated with cognitive benefits: an 8-wk, randomized, double-blind, placebo-controlled trial in healthy older adults.

BACKGROUND: Research indicates that the chronic consumption of flavonoids is associated with cognitive benefits in adults with mild cognitive impairment and neurodegenerative disease, although to our knowledge, there have been no such studies in healthy older adults. Furthermore, the effects of commonly consumed orange juice flavanones on cognitive function remain unexplored. OBJECTIVE: We investigated whether 8 wk of daily flavanone-rich orange juice consumption was beneficial for cognitive function in healthy older adults. DESIGN: High-flavanone (305 mg) 100% orange juice and an equicaloric low-flavanone (37 mg) orange-flavored cordial (500 mL) were consumed daily for 8 wk by 37 healthy older adults (mean age: 67 y) according to a crossover, double-blind, randomized design separated by a 4-wk washout. Cognitive function, mood, and blood pressure were assessed at baseline and follow-up by using standardized validated tests. RESULTS: Global cognitive function was significantly better after 8-wk consumption of flavanone-rich juice than after 8-wk consumption of the low-flavanone control. No significant effects on mood or blood pressure were observed. CONCLUSIONS: Chronic daily consumption of flavanone-rich 100% orange juice over 8 wk is beneficial for cognitive function in healthy older adults. The potential for flavanone-rich foods and drinks to attenuate cognitive decline in aging and the mechanisms that underlie these effects should be investigated.

Blueberry supplementation induces spatial memory improvements and region-specific regulation of hippocampal BDNF mRNA expression in young rats.

RATIONALE: Flavonoid-rich foods have been shown to be able to reverse age-related cognitive deficits in memory and learning in both animals and humans. However, to date, there have been only a limited number of studies investigating the effects of flavonoid-rich foods on cognition in young/healthy animals. OBJECTIVES: The aim of this study was to investigate the effects of a blueberry-rich diet in young animals using a spatial working memory paradigm, the delayed non-match task, using an eight-arm radial maze. Furthermore, the mechanisms underlying such behavioural effects were investigated. RESULTS: We show that a 7-week supplementation with a blueberry diet (2 % w/w) improves the spatial memory performance of young rats (2 months old). Blueberry-fed animals also exhibited a faster rate of learning compared to those on the control diet. These behavioural outputs were accompanied by the activation of extracellular signal-related kinase (ERK1/2), increases in total cAMP-response element-binding protein (CREB) and elevated levels of pro- and mature brain-derived neurotrophic factor (BDNF) in the hippocampus. Changes in hippocampal CREB correlated well with memory performance. Further regional analysis of BDNF gene expression in the hippocampus revealed a specific increase in BDNF mRNA in the dentate gyrus and CA1 areas of hippocampi of blueberry-fed animals. CONCLUSIONS: The present study suggests that consumption of flavonoid-rich blueberries has a positive impact on spatial learning performance in young healthy animals, and these improvements are linked to the activation of ERK-CREB-BDNF pathway in the hippocampus.