Cardiovascular Function During Supine Rest in Endurance Trained Males with New Zealand Blackcurrant: A Dose-Response Study

Purpose Blackcurrant contains anthocyanins that could alter cardiovascular function and reduce cardiovascular disease risk. We examined dose responses of New Zealand blackcurrant (NZBC) extract on cardiovascular function during supine rest. Methods Fifteen endurance trained male cyclists (age: 38±12 years, height: 178±5 cm, body mass: 76±10 kg, V?O2max: 56±8 mL?kg-1?min-1, mean±SD) were randomly assigned using a counterbalanced Latin square design to complete four conditions, a control of no NZBC, or one of three doses (300, 600 or 900 mg?day-1) of NZBC extract (CurraNZTM) for seven-days with a fourteen-day washout. Cardiovascular function (i.e. blood pressure, heart rate, ejection time, cardiac output, stroke volume and total peripheral resistance) during supine rest was examined (Portapres® Model 2). Results Systolic and diastolic blood pressure, heart rate and ejection time were unchanged by NZBC. A dose effect (P<0.05) was observed for cardiac output, stroke volume and total peripheral resistance. A trend for a dose effect was observed for mean arterial blood pressure. Cardiac output increased by 0.6±0.6 L·min-1 (15%) and 1.0±1.0 L·min-1 (28%) and stroke volume by 5±8 mL (7%) and 6±17 mL (18%) between control and 600, and 900 mg?day-1, respectively. Total peripheral resistance decreased by 4±3 mmHg·L-1·min-1 (20%) and 5±9 mmHg·L-1·min-1 (20%) for 600, and 900 mg?day-1. Conclusion Seven-days intake of New Zealand blackcurrant extract demonstrated dose-dependent changes on some cardiovascular parameters during supine rest in endurance-trained male cyclists.