[Seminar] Linking the bioavailability of dietary polyphenols to mechanisms and physiological effects in humans

Seminar

Title: Linking the bioavailability of dietary polyphenols to mechanisms and physiological effects in humans

Speaker: Paul A Kroon

Affiliation: Institute of Food Research, Norwich Research Park, Norwich, Norfolk, UK.

 

Abstract:

Although there are numerous reports providing data showing beneficial effects of consuming polyphenol-rich foods on human health (mainly cardiovascular health), the search for underlying mechanisms has been complicated because of the extensive metabolism of polyphenols that occurs post-consumption and a lack of mechanistic studies using metabolites. We have focussed our research on studies designed to take bioavailability and metabolism into account when investigating mechanisms. Also, we have focussed our dietary interventions on comparing polyphenol-rich with similar but polyphenol-poor foods so that we can ascribe the observed effects on risk factors and other biomarkers to the polyphenols. For example, in our studies with the ApoE-/- mouse model of atherosclerosis we have compared the effects of control red and anthocyanin-rich purple tomatoes on aortic sinus plaque area, while an ongoing human dietary intervention study is comparing anthocyanin-rich blood orange juice with anthocyanin-free standard orange juice. We have also undertaken randomised controlled trials using encapsulated polyphenol-rich extracts and compared these with placebos. In our pre-clinical cultured cell-based mechanistic studies, we assess the ability of authentic human metabolites to beneficially alter biomarkers associated with vascular health. In addition, we increasingly use human metabolite profiling and transcript profiling approaches to assess responses both in vitro and in vivo. Examples of these approaches will be presented and their advantages highlighted.

paul.kroon@ifr.ac.uk