Effect of Intake Duration of Anthocyanin-Rich New Zealand Blackcurrant Extract on Cardiovascular Responses and Femoral Artery Diameter during Sustained Submaximal Isometric Contraction

Abstract

Seven-day intake of anthocyanins from New Zealand blackcurrant (NZBC) extract increased cardiac output and femoral artery diameter during a sustained submaximal isometric contraction. It is not known if there are intake duration effects by NZBC extract on the isometric contraction-induced cardiovascular responses. In a repeated measures design, male participants (n = 19, age: 26 ± 4 years) performed a 120-second submaximal (30%) isometric contraction of the knee extensors at baseline and following 1, 4 and 7-days intake of 600 mg·day⁻¹ NZBC extract. During the 120-second submaximal isometric contraction, femoral artery diameter and cardiovascular responses were measured with ultrasound and beat-to-beat hemodynamic monitoring. Femoral artery was larger following 4-days (mean difference = 0.046 cm, 95% CI [0.012, 0.080], p = 0.005) and 7-days (mean difference = 0.078 cm, 95% CI [0.034, 0.123], p < 0.001) in comparison to baseline with no increase with 1-day intake. Systolic and diastolic blood pressure, heart rate and total peripheral resistance were not changed by NZBC extract at 1, 4 and 7-days intake. However, mean arterial pressure, stroke volume, cardiac output and total peripheral resistance were changed at time points during the isometric contraction following 7-days intake in comparison to 1-day intake of NZBC extract (p < 0.05). Alterations in femoral artery diameter and some cardiovascular responses during a submaximal sustained isometric contraction of the knee extensors are affected by the intake duration of New Zealand blackcurrant extract, with no effects by 1-day intake. Our observations suggest that the bioavailability of blackcurrant anthocyanins and anthocyanin-derived metabolites is required for days to alter the mechanisms for isometric-contraction induced cardiovascular responses.

Keywords:

• anthocyanins
• blood flow
• isometric contraction
• New Zealand blackcurrant

Acknowledgements

Supply of supplement (CurraNZ^®) for the present study was obtained from Health Currancy Ltd (United Kingdom) and CurraNZ Ltd (New Zealand) but had no role in any aspect of the study and manuscript. Experiments were performed in the Institute of Sport at the University of Chichester (UK).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Matthew David Cook

Matthew David Cook is a Lecturer of Sport and Exercise Science in the School of Sport and Exercise Science at the University of Worcester (UK). His research interests are exercise physiology and sports nutrition

Aaron Dunne

Aaron Dunne has a MSc in Sport and Exercise Physiology from the University of Chichester (UK) He is aiming to pursue a PhD on heart rate variability in sport

Michael Bosworth

Michael Bosworth has a MSc in Sport and Exercise Physiology from the University of Chichester (UK). He is currently employed with a private hospital in the UK

Mark Elisabeth Theodorus Willems

Mark Elisabeth Theodorus Willems is a Professor of Exercise Physiology in the Institute of Sport at the University of Chichester (UK). His research interests are sports and exercise nutrition, exercise physiology and muscle physiology