Flavonoids and cardiovascular disease risk factors – a meta-analysis and recent findings from prospective cohort studies

Our recent meta-analysis of randomized clinical trials provides a snapshot of the current state-of-the-art in relation to the relative effectiveness of the different flavonoid subclasses in modifying biomarkers of cardiovascular (CVD) risk and highlights areas in which limited data exists. The available data suggests there may be clinically relevant effects of some flavonoid subclasses on cardiovascular risk factors, and to date the effects of flavonoids from soy and cocoa have been the main focus of attention. Chocolate/cocoa increased FMD acutely (3.99%; 95% CI: 2.86, 5.12; six studies) and chronically (1.45%; 0.62, 2.28; two studies) and reduced both systolic blood pressure (–5.88mmHg; –9.55, –2,21; five studies) and diastolic blood pressure (–3.30mm Hg; –5.77, –0.83; four studies) following chronic intake. Only soy protein isolate, but not whole soy or soy extracts, reduced diastolic blood pressure (–1.99mm Hg; –2.86, –1.12; nine studies) and LDL cholesterol (–0.19 mmol/L; –0.24, –0.14; thirty-nine studies). For many subclasses (anthocyanins and flavanones) there was insufficient evidence to draw conclusions about efficacy. We are currently updating the review, including all studies conducted through until Jan 2010 with a view to also examine potential structure-activity relationships. Recent data from ongoing collaborations with the Harvard cohorts (Nurses Health Study and Helath Professionals Follow-up Study) on flavonoid sub-class intake and cardiovascular health endpoints will also be discussed.