The effects of resveratrol on cognition, cerebral blood flow, gastrointestinal microbiota and systemic inflammation in healthy weight, overweight and obese adults

Abstract

The stilbene polyphenol resveratrol has been shown to interact with several health-promoting mechanisms, which might impact cognitive performance. However previous research has indicated that resveratrol supplementation is not able to impact cognitive performance in young, healthy adults; despite consistent ability to modulate cerebral blood flow. Recent work suggests that resveratrol supplementation may be more beneficial in individuals who are compromised by age, disease, or overweight status. Specifically, obese individuals are characterised by a multitude of health issues including sustained inflammation, elevated cholesterol levels; excessive fat accumulation and neuroinflammation; here resveratrol supplementation offers a therapeutic option. Moreover, a recent shift in literature focus indicates the importance of gut microbial composition on host-health; and specifically, how this can be modified by dietary intervention. Obesity is associated with dysbiosis of the microbiota, disruption to the intestinal barrier and exacerbated pro-inflammatory response; where it is hypothesised that polyphenol intervention may have the capability to modulate microbial composition and exert health-promoting effects. With said health promoting effects of polyphenolic-gut-modulation potentially also extending to cognitive function, via the gutbrain-axis. Therefore, the two randomised, placebo-controlled, double-blind intervention trials included in this thesis aimed to investigate the effects of resveratrol supplementation on cognitive function, cerebral blood flow, inflammation and gastrointestinal microbiota in healthy adults of varying weight status. The key findings here indicate that as in young, healthy adults, resveratrol supplementation results in clear modulation of CBF in healthy overweight-obese adults. Furthermore, it confirms that within this population, resveratrol is unable to exert cognitive enhancing effects, with limited evidence of a detrimental effect observed. Limited changes in microbial composition indicate that this is likely a promising avenue for future investigations of either resveratrol or other polyphenolic or dietary intervention.

Date of Award	30 May 2022
Original language	English
Awarding Institution	Northumbria University
Supervisor	Emma Wightman (Supervisor), David Kennedy (Supervisor) & Darren Smith (Supervisor)