Effects of blackcurrant extract on arterial functions in older adults: A randomized, double-blind, placebo-controlled, crossover trial

ABSTRACT

Purpose

Blackcurrant extract mainly contains anthocyanins. Several reports suggest that anthocyanins have beneficial effect for cardiovascular functions. The aim of this study was to examine the effect of 7-day intake of New Zealand blackcurrant (NZBC) extract on arterial functions, e.g. arterial stiffness, and serum lipids.

Methods

A randomized, double-blind, placebo-controlled, crossover design study with a washout period of 28 days was conducted. Fourteen older adults participated in this study (age 73.3 ± 1.7 years). Participants took either a 7-day course of placebo or two capsules of NZBC extract (each 300 mg capsule contains 35% blackcurrant extract). Participants took one of the two trials first and then took the other after a washout period. Carotid-femoral pulse-wave velocity, an index of central arterial stiffness, and central blood pressure were measured at baseline and again at the end of the 7-day study period.

Results

Compared to baseline, carotid-femoral pulse-wave velocity (P = .03) and central blood pressure (P = .02) decreased significantly after the 7-day study period with NZBC intake. In addition, carotid-femoral pulse-wave velocity (P = .04) and central blood pressure (P = .001) in the NZBC intake trial decreased significantly more than in the placebo intake trial. No effects were observed on serum lipids.

Conclusion

These results suggest that short-term NZBC intake reduces central arterial stiffness and central blood pressure in older adults. Therefore, anthocyanin-rich blackcurrants might be beneficial for maintaining or improving cardiovascular health as an alternative to pharmaceutical medications.

Abbreviations

Aix: augmentation index; BP: blood pressure; cfPWV: carotid–femoral pulse-wave velocity;  CVD: cardiovascular diseases; DBP: diastolic blood pressure;  faPWV: femoral-ankle pulse-wave velocity; FG: fasting glucose; HDL: high-density lipoprotein cholesterol; LDL: low-density lipoprotein cholesterol; MBP: mean blood pressure; NZBC: New Zealand blackcurrant; PP: pulse pressure; SBP: systolic blood pressure; TG: triglycerides.

KEYWORDS:

• Anthocyanins
• pulse wave velocity
• augmentation index
• vascular function
• cardiovascular risk factors

Acknowledgments

The authors would like to thank Mr. Hiroyuki Hatakeyama for technical assistance with the experiments.

Compliance with ethical standards

Conflict of interest

The authors have no conflict of interest to declare.

Informed consent

Informed consent was obtained from all participants.

Statement of human and animal rights

This study was approved by the Ethics Committee of Nippon Sport Science University.

Additional information

Funding

There are no funding sources for the present study.