Investigation of the impact of short and long-term flavonoid intake on human cognitive performance

Alharbi, M. H. J. (2017) Investigation of the impact of short and long-term flavonoid intake on human cognitive performance. PhD thesis, University of Reading.

Abstract/Summary

Background: Fruit, vegetables and their derivative products, including juices and cocoa, are rich in f1avonoids that have been observed to acutely improve cognition and/or to maintain a better cognitive function over time. The aim was to further investigate the potential of f1avonoids to act upon human cognitive function. Experimental: overall this project involved 132 healthy participants in different age groups to further demonstrates the potential of flavonoids to act upon human cognitive function. Firstly, the intake effect of habitual dietary flavonoids from fruit and vegetables on the cognitive function of 76 elderly participants over a four-year period. Next, an acute placebo-controlled intervention study with flavanone-rich orange juice in 22 middle-aged participants. A final sub¬chronic study examined consumption of epicatechin (EC) 70 mg in milk chocolate in 34 young participants. Result: findings of the first study showed that a wide range of cognitive functions were affected; memory, global function, and executive function; those in the highest quartile of consumption (761 .14 -1638.65 mg/d), showed the greatest change in score from the initial assessment. The research also presented an association between the final assessment of cognitive function and the intake of the flavonoid subclasses such as anthocyanin, flavones, f1avanols and proanthocyanidins (PAs), In addition, consumption of flavanols, flavonols, PAs, f1avones and flavanones was associated with a change over time. Second study revealed an improvement following consumption of favanone orange juice (OJ) in executive function and psychomotor speed, mood (alertness) and global cognition. Final study concluded that EC showed chronic effect (in follow up time point after cut off the treatment) on executive function, global cognition and blood pressure. Conclusion: these data indicates that different flavonoids may affect different cognitive domains although these results are preliminary and require further investigation.