Acute reduction in blood pressure following consumption of anthocyanin-rich cherry juice may be dose-interval dependant : a pilot cross-over study

A pilot cross-over study assessed the acute effects on blood pressure and plasma biomarkers associated with consumption of a 300 ml anthocyanin-rich fruit juice, provided in differing dose-intervals. Young adults (n ¼ 6) and older adults (n ¼ 7) received in random order, either a single 300 ml dose or 3 100 ml doses of high-flavonoid cherry juice provided at 0, 1 and 2 h. Blood pressure and plasma levels of phenolic metabolites were measured at 0, 2 and 6 h. The single 300 ml dose of cherry juice resulted in a significant reduction in systolic (p ¼ 0.002), and diastolic blood pressure (p ¼ 0.008) and heart-rate (p ¼ 0.033) 2 h after consumption, before returning to baseline levels at 6 h post-consumption. The 3 100 ml dose provided over 2 h did not result in significant blood pressure reductions. Plasma phenolic metabolites increased at 2 and 6 h; however, fluctuations were higher after the single 300 ml dose in older adults. These findings have implications for design of intervention studies that investigate vascular effects associated with flavonoid-rich foods.