Dr Rianne Costello

New Zealand blackcurrant (NZBC) extract is a rich source of anthocyanins and in order to exert physiological effects, the anthocyanin-derived metabolites need to be bioavailable in vivo. We examined the plasma uptake of selected phenolic acids following NZBC extract supplementation alongside maintaining a habitual diet (i.e., not restricting habitual polyphenol intake). Twenty healthy volunteers (9 females, age: 28±7 years, height 1.73±0.09 m, body mass 73±11 kg) consumed a 300 mg NZBC extract capsule (CurraNZ™; anthocyanin content 105 mg) following an overnight fast. Venous blood samples were taken pre and 1, 1.5, 2, 3, 4, 5, and 6 h post-ingestion of the capsule. Plasma concentrations of vanillic acid (VA), gallic acid (GA), and protocatechuic acid (PCA) were analysed by reversed-phase high-performance liquid chromatography (HPLC) and the HPLC analysis identified two dihydroxybenzoic (VA and PCA) and one trihydroxybenzoic acids (GA) in plasma following NZBC extract supplementation. Habitual anthocyanin intake was 168 (95%CI:68–404) mg⋅day-1 and no associations were observed between this and VA, PCA, and GA plasma uptake by the NZBC extract intake. Plasma time-concentration curves revealed that GA, and PCA were most abundant at 4, and 1.5 h post-ingestion, representing a 261% and 320% increase above baseline, respectively, with VA remaining unchanged. This is the first study to demonstrate that an NZBC extract supplement increases the plasma uptake of phenolic acids GA, and PCA even when a habitual diet is followed in the days preceding the experimental trial, although inter-individual variability is apparent.

New Zealand blackcurrant (NZBC) contains anthocyanins, known to moderate blood flow and display anti-inflammatory properties that may improve recovery from exercise-induced muscle damage. The authors examined whether NZBC extract supplementation enhances recovery from exercise-induced muscle damage after a half-marathon race. Following a randomized, double-blind, independent groups design, 20 (eight women) recreational runners (age 30 ± 6 years, height 1.73 ± 0.74 m, body mass 68.5 ± 7.8 kg, half-marathon finishing time 1:56:33 ± 0:18:08 hr:min:s) ingested either two 300-mg/day capsules of NZBC extract (CurraNZ™) or a visually matched placebo, for 7 days prior to and 2 days following a half-marathon. Countermovement jump performance variables, urine interleukin-6, and perceived muscle soreness and fatigue were measured pre, post, and at 24 and 48 hr after the half-marathon and analyzed using a mixed linear model with statistical significance set a priori at p .05). Urine interleukin-6 increased 48-hr post-half-marathon in the NZBC group only (p .05). Perceived muscle soreness and fatigue increased immediately post-half-marathon (p .05). Supplementation with NZBC extract had no effect on the recovery of countermovement jump variables and perceptions of muscle soreness or fatigue following a half-marathon in recreational runners.

Objectives. This study investigated the effect of 7 days’ supplementation with New Zealand blackcurrant
extract on thermoregulation and substrate metabolism during running in the heat. Design. Randomized, double-blind, cross-over study. Methods. Twelve men and six women (mean ± SD: Age 27 ± 6 years, height 1.76 ± 0.10 m, mass 74 ± 12 kg, V˙ O2max 53.4 ± 7.0 mL kg−1 min−1) completed one assessment of maximal aerobic capacity and one familiarisation trial (18 ◦C, 40% relative humidity, RH), before ingesting 2 × 300 mg day−1 capsules of CurraNZTM (each containing 105 mg anthocyanin) or a visually matched placebo (2 × 300 mg microcrystalline cellulose M102) for 7days (washout 14 days). On day 7 of each supplementation period, participants completed 60 min of fasted running at 65% V˙ O2max in hot ambient conditions (34 ◦C and 40% relative humidity). Results: Carbohydrate oxidation was decreased in the NZBC trial [by 0.24 g min−1 (95% CI: 0.21–0.27 g min-1)] compared to placebo (p = 0.014, d = 0.46), and fat oxidation was increased in the NZBC trial [by 0.12 g min−1 (95% CI: 0.10 to 0.15 g min−1)], compared to placebo (p = 0.008, d = 0.57). NZBC did not influence heart rate (p = 0.963), rectal temperature (p = 0.380), skin temperature (p = 0.955), body temperature (p = 0.214) or physiological strain index (p = 0.705) during exercise. Conclusions. Seven-days intake of 600 mg NZBC extract increased fat oxidation without influencing
cardiorespiratory or thermoregulatory variables during prolonged moderate intensity running in hot
conditions.