Acute ingestion of a single dose of blackcurrant extract maintained forearm blood flow and forearm vascular resistance during an extended period of sitting. - GreenMedInfo Summary

We examined the acute effects of anthocyanin-rich New Zealand blackcurrant extract and a placebo on hemodynamics during 120 min of sedentary sitting in healthy males. Additionally, we investigated whether changes in resting hemodynamics altered repeated isometric hand-grip exercise performance and post exercise forearm blood flow (FBF).Ten healthy males completed two trials during which they ingested either blackcurrant extract (1.87 mg total anthocyanins/kg bodyweight) or placebo powder. Heart rate, blood pressure and forearm blood flow were measured, and venous blood was sampled, prior to and 30, 60, 90 and 120 min-post ingestion. Participants remained seated for the duration of each trial. At 120 min post-ingestion participants completed as many repetitions of isometric hand-grip contractions as possible.Heart rate, blood pressure and mean arterial pressure changed over time (all<0.001) but did not differ between treatments. A treatment x time interaction for FBF (= 0.025) and forearm vascular resistance (FVR) (= 0.002) was found. No difference in the number of isometric hand-grip contractions was observed between treatments (= 0.68) nor was there any treatment x time interaction in post-exercise FBF (= 0.997). Plasma endothelin-1 (= 0.023) and nitrate (= 0.047) changed over time but did not differ between treatments (both>0.1). Plasma nitrite did not change over time (= 0.732) or differ between treatments (= 0.373).This study demonstrated that acute ingestion of a single dose of blackcurrant extract maintained FBF and FVR during an extended period of sitting; however, this did not influence exercise performance during hand-grip exercise.