Abstract/Summary

Fruits rich in flavonoids have shown positive effects on cognitive performance, mental health and mood in both animals and adult humans, possibly via their ability to influence neuronal connectivity and protect against neurodegeneration. However, evidence regarding the translation of such effects to children is more limited. The aim of my thesis was to evaluate whether supplementation of flavonoids from fruit can improve cognitive function, mood, and academic attainment in 11-13 year old children. Initially, a 12 weeks daily supplementation study using 40 gram portion of high-flavonoid (HF) or low-flavonoid (LF) fruit with baseline and post-intervention measurement of cognition performance and mood was carried out. Improvement in a composite score of executive function and reduction in negative mood affect following HF intake was observed. However, no effect on memory and overall academic attainment were found. To test and extent the reliability of the effect of flavonoid supplementation on executive function and negative affect seen in Experiment 1, a second supplementation study was conducted comprising of a double portions of HF and LF fruits (80 gram) compared to a control group over 7 week intervention. The means for executive function and negative affect revealed the same trend as in the previous experiment however, the significant differences were not replicated. Finally, the discrepancies in results of Experiment 1 and 2 were further explored in a final experiment where children were supplemented with 80 gram of HF or LF fruit conditions for 12 weeks. Paper and pencil cognitive tasks and mood were measured at baseline and post intervention. Disappointingly, despite the much larger sample size, an absence of significant differences between groups was observed similar to Experiment 2. In conclusion, mixed evidence at best was found for the effects of flavonoid rich fruit supplementation on composite score of executive function and mood, with no evidence of effects on academic performance in 11-13 year old children. Crucially, though this pattern was not consistently observed throughout the studies. Further research in children is required to investigate the association between flavonoid rich fruits in cognitive and academic outcomes utilising longer supplementation durations and higher content of flavonoids to better characterise their potential effects in school age children.