Intake Duration of Anthocyanin-Rich New Zealand Blackcurrant Extract Affects Cardiovascular Responses during Moderate-Intensity Walking But Not at Rest.

We examined effects of intake duration of New Zealand blackcurrant (NZBC) extract on cardiovascular responses during supine rest and moderate-intensity walking. Recreationally active men ( = 15, age: 24 ± 6 yr, BMI: 24.7 ± 4.3 kg·m) volunteered in a randomized, cross-over design. One metabolic equivalent (1-MET) was measured (3.97 ± 0.66 mL·kg·min) and an incremental walking test was performed to individualize speed at 4 ( = 3) or 5 ( = 12) METs for the 30-min walk (5.7 ± 0.7 km·hr). NZBC extract (210 mg of anthocyanins) was taken with breakfast for 7 and 14 days, with a 14-days washout. The final dose was ingested 2-hr before recording of the cardiovascular responses (Portapres Model-2). At rest, %changes at 7- and 14-days intake were observed for stroke volume (+6.8% (trend),  = 0.065; +8.5%,  = 0.012), cardiac output (+10.1%,  = 0.007; +8.5%,  = 0.013), total peripheral resistance (-12.0%,  = 0.004; -13.1%,  = 0.011), diastolic (-5.7%,  = 0.045; -9.7%,  = 0.015) and mean arterial pressure (-4.4%,  = 0.040; -7.2%,  = 0.029), but without intake duration effect. During walking, %changes at 7- and 14-days intake were observed for stroke volume (+7.7% (trend),  0.063; +9.9%,  0.006), cardiac output (+8.7%,  0.037; +10.1%,  = 0.007), diastolic blood pressure (-6.2%,  0.042; -10.6%,  = 0.001), and total peripheral resistance (-9.6%,  0.042; -13.5%,  = 0.005) but without intake duration effect. During walking, %changes at 14-days were observed only for mean arterial pressure (-6.4%,  = 0.018) and arterio-venous oxygen difference (-7.9%,  = 0.019). NZBC extract affects cardiovascular responses at rest and during moderate-intensity exercise with 7- and 14-day intake. Only during moderate-intensity exercise, a longer intake of NZBC extract was required for an effect on some cardiovascular responses.