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, [Formula: see text]: 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 (CurraNZ™) for 7-days with a 14-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.
Keywords: Anthocyanins; Cardiovascular function; New Zealand blackcurrant; Polyphenols; Sports nutrition.