Data from prospective cohort studies highlight the beneficial impact of higher habitual
intakes of specific sub-classes of bioactive dietary constituents called flavonoids
on both biomarkers of cardiovascular (CV) risk and disease outcomes including myocardial
infarction (MI) and type 2 diabetes. Emerging data suggest that intake of specific
flavonoids may also help with weight maintenance, cognitive function and depression.
Following ingestion, flavonoids are extensively metabolised (by Phase I & II metabolism
and the gut microbiome) with the gut microbiome likely playing a key metabolic role,
catabolising unabsorbed constituents into smaller molecules such as phenolic and aromatic
acids, which are also absorbed. For flavonoids consumed in the diet, the parent compounds
may not be responsible for bioactivity; instead this may be mediated by metabolites
present in the systemic circulation. Data from limited available trials show that
following intake there is extensive variability in metabolite levels. This wide inter-individual
variability in metabolism (15 – 99% of the ingested intake recovered as a wide range
of urinary metabolites) suggests that metabolism may be critical in explaining the
differential responses in cardiovascular risk biomarkers observed in clinical trials
(responders v non-responders).
The focus of the presentation will be on the developing evidence base for two sub-class
of flavonoids (anthocyanins and flavan-3-ols), discussing the available data from
clinical trials and large epidemiological studies.
