The aim of this thesis was to examine the effects of postprandial glycaemia on cognition and mood. Three studies provided evidence that low GL meals/drinks result in cognitive superiority. Study 1 found that Children's (n = 75) memory and mood were improved 180 minutes after eating a breakfast (cereal, yogurt, orange flavour drink, 337kcal) sweetened with 40g isomaltulose (low GL) rather than 40g glucose (high GL). Study 2 examined the interaction between gluco-regulatory status of older adults (n=153) and the GL of breakfast. Older adults with better, but not poorer glucose tolerance, had better memory and mood if they ate breakfast (toast, yogurt, orange flavour drink, 275kcal) sweetened with 40g isomaltulose (low GL), rather than 40g glucose (high GL) or 40g sucrose (medium GL). Conversely, older adults with poorer glucose tolerance had better memory and mood 30 minutes after glucose but not a sucrose or isomaltulose based meal. Individual differences in gluco-regulatory control also interacted with age to predict cognitive performance, cognitive decline and mood. Adults aged 61 or above, with poorer glucose tolerance, had poorer memory than those 61 or over with better glucose tolerance, or those 60 and younger with poorer glucose tolerance. In addition, in older adults with poor glucose tolerance, developing subsequent low blood glucose levels was associated with better cognitive performance, mood and less cognitive decline. Study 3 investigated the interaction between caffeine (80mg) and the GL of its vehicle. After drinking caffeine young adults (n= 345) had poorer glucose tolerance. Caffeine, regardless of vehicle, improved young adult's memory, reaction times and vigilance. Young adults remembered more words, after 150 minutes, if they drank milk (250ml, 155kcal, low GL), rather than glucose (250ml drink with 30g glucose, 155kcal, high GL), and had better working memory, after 90 and 150 minutes, if they drank water (250ml), or milk, rather than glucose. After 30 minutes, caffeine increased subjective energy levels, however, when caffeine was taken with water energy levels were reduced after 90 and 150 minutes. In contrast, when caffeine was consumed with milk greater energy was reported after 90 and 150 minutes. Caffeine did not affect energy levels when it was drunk with glucose. These results were discussed in relation to an emerging understanding of the pathologies that underlie disturbed glucose homeostasis and how these relate to the brain and cognitive performance. A theoretical framework was put forward which aims to direct future research.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:678596 |
| Date | January 2013 |
| Creators | Young, Hayley Anne |
| Publisher | Swansea University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://cronfa.swan.ac.uk/Record/cronfa43174 |
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