Blueberry Anthocyanins: Assessing the Mediating Effect of a Novel Anthocyanin Metabotype on Acute Postprandial Cardiometabolic Health

Flynn, Caoimhe (2021) Blueberry Anthocyanins: Assessing the Mediating Effect of a Novel Anthocyanin Metabotype on Acute Postprandial Cardiometabolic Health. Doctoral thesis, University of East Anglia.

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Abstract

Epidemiological evidence has associated anthocyanin intake, a subclass of flavonoids, with reduced cardiovascular disease risk; yet randomised controlled trial (RCT) data is equivocal. Interindividual variation in intervention response, mediated by differential metabolism, has been hypothesised as an underlying factor for inconsistent RCT findings. To date, however, the cardiometabolic consequences of anthocyanin metabolism profiles has not been confirmed by prospective volunteer recruitment to studies.

In this thesis, the flow-mediated dilation ultrasound technique was used to assess brachial artery endothelial function. Retrospective, exploratory analysis was performed, to establish the relevance of measuring an extended blood vessel parameters including time-to-peak, and low and high flow-mediated constriction. Subsequently, overweight older adults, prospectively recruited by quantification of four key colonic derived metabolites, were enrolled in a single-dose, crossover RCT. This study compared cardiometabolic responses for 48 hours, following blueberry or matched control intake alongside a basal metabolic rate and physical activity adjusted energy-dense meal.

Despite low study numbers restricting the capacity to test the study hypothesis (due to COVID-19 study abandonment), ‘LOW’ metabolisers had larger blood pressure reductions at 24 and 48 hours after blueberries. Whilst not anticipated, notably LOW metabolisers had habitually higher concentrations of key metabolites and arguably more ‘healthful’ diets i.e., higher wholegrains and tea; lower fat and beer intakes. When aligned with an existing background of healthier diet choices, the inclusion of blueberries appeared to reduce the burden of energy-dense meals. Additionally, assessments were made to identify whether absolute fat content and composite measures of health (QRISK3) were important design characteristics for future studies.

In summary, LOW metabolisers may uniquely experience vascular benefits from blueberry anthocyanins, and this may be influenced by their habitual diet and the capacity of their pre-existing gut microbiome to habitually produce key metabolites. Further research with adequately powered studies is required to confirm this.

Item Type: Thesis (Doctoral)
Faculty \ School: Faculty of Medicine and Health Sciences > Norwich Medical School
Depositing User: Chris White
Date Deposited: 03 Oct 2022 11:52
Last Modified: 03 Oct 2022 11:52
URI: https://ueaeprints.uea.ac.uk/id/eprint/88788
DOI:

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