Topical Area: Sports Nutrition
Objectives : New Zealand blackcurrant (NZBC) is an anthocyanin-rich berry with potential effects on cardiovascular health (e.g. 7-day NZBC extract lowered total peripheral resistance at rest). We examined effects of 7- and 14-day intake of NZBC extract on cardiovascular responses during moderate intensity exercise.
Methods : Fifteen healthy men (mean±SD, age: 24±6 yr, body mass: 79±16 kg, height: 178±6 cm, BMI: 24.7±4.3 kg·m-2, IPAQ score: 4534±1576 MET·week-1) volunteered. Resting metabolic equivalent (1-MET) was measured using Douglas bags (1-MET: 3.97±0.66 ml·kg-1·min-1) with an incremental walking test to determine the relationship between walking speed and MET. A randomised, cross-over experimental design was used for baseline, 7-day and 14-day intake. Participants consumed 2 capsules of NZBC extract (600 mg and containing 210 mg of anthocyanins, CurraNZ™ Health Currancy Ltd., UK) with breakfast with a 14-day washout. On the morning of testing, the final 2 capsules were ingested 2-hr before the 30-min walk at 4 (n=3) or 5 (n=12) METs (speed: 5.68±0.67 km·hr-1). Cardiovascular responses were measured at 7-10, 17-20 and 27-30 min during the walk (Portapres Model 2), averaged and analysed (ANOVA and post-hoc t-tests).
Results : Intake duration had no effect on heart rate (e.g. baseline: 102±18 beats·min-1), systolic blood pressure (e.g. baseline 158±18 mm Hg) and ejection time (e.g. baseline: 0.28±0.03 s). Cardiac output (baseline: 11.7±2.0, 7-day: 12.7±2.5, 14-day: 12.7±2.1 L·min-1, P=0.012) and stroke volume (baseline: 114±13, 7-day: 123±22, 14-day: 126±21 mL·min-1, P=0.017) were increased, and total peripheral resistance (baseline: 0.51±0.11, 7-day: 0.46±0.17, 14-day: 0.44±0.12 mmHg·L-1·min-1, P=0.018) and diastolic blood pressure (baseline 71±9, 7-day: 66±10, 14-day: 63±11 mm Hg, P=0.002) were lower for 7- and 14-day intake. Only 14-day intake resulted in lower mean arterial pressure (baseline: 93±10, 7-day: 89±9, 14-day: 87±11 mm Hg, P=0.034).
Beneficial effects of anthocyanin-rich NZBC extract intake on cardiovascular responses during moderate intensity exercise do not require long-duration intake.
Funding Sources :
Health Currancy (UK) Ltd and CurraNZ (NZ) Ltd provided supplements and support for conference attendance with Blackcurrant New Zealand Inc. (NZ).