Consumption of an Anthocyanin-Rich Extract Made From New Zealand Blackcurrants Prior to Exercise May Assist Recovery From Oxidative Stress and Maintains Circulating Neutrophil Function: A Pilot Study

Abstract

Aim: To evaluate blackcurrant anthocyanin-rich extract (BAE) consumption on time- and dose-dependent plasma anthocyanin bioavailability and conduct a pilot study to explore the potential effect of BAE in promoting recovery from exercise-induced oxidative stress, and maintenance of circulating neutrophil function. Methods: Time- and dose-dependent blackcurrant anthocyanin bioavailability was assessed using LC-MS in 12 participants over 6 h after the ingestion of a placebo or BAE containing 0.8, 1.6, or 3.2 mg/kg total anthocyanins. In a separate pilot intervention exercise trial, 32 participants consumed either a placebo or 0.8, 1.6, or 3.2 mg/kg BAE (8 individuals per group), and then 1 h later performed a 30 min row at 70% VO 2 max. Blood was collected during the trial for oxidative, antioxidant, inflammatory, and circulating neutrophil status. Results: Consumption of BAE caused a time- and dose-dependent increase in plasma anthocyanins, peaking at 2 h after ingestion of 3.2 mg/kg BAE (217 ± 69 nM). BAE consumed 1 h prior to a 30 min row had no effect on plasma antioxidant status but hastened the recovery from exercise-induced oxidative stress: By 2 h recovery, consumption of 1.6 mg/kg BAE prior to exercise caused a significant ( P < 0.05) 34 and 32% decrease in post-exercise plasma oxidative capacity and protein carbonyl levels, respectively, compared to placebo. BAE consumption prior to exercise dose-dependently attenuated a small, yet significant ( P < 0.01) transient 13 ± 2% decline in circulating neutrophils observed in the placebo group immediately post-exercise. Furthermore, the timed consumption of either 1.6 or 3.2 mg/kg BAE attenuated a 17 ± 2.4% ( P < 0.05) decline in neutrophil phagocytic capability of opsonised FITC- Escherichia coli observed 6 h post-exercise in the placebo group. Similarly, a dose-dependent increase in neutrophil surface expression of complement receptor-3 complex (CR3, critical for effective phagocytosis of opsonised microbes), was observed 6 h post-exercise in both 1.6 and 3.2 mg/kg BAE intervention groups. Conclusions: Consumption of BAE (>1.6 mg/kg) 1 h prior to exercise facilitated recovery from exercise-induced oxidative stress and preserved circulating neutrophil function. This study provides data to underpin a larger study designed to evaluate the efficacy of timed BAE consumption on post-exercise recovery and innate immunity.

Daily Consumption of an Anthocyanin-Rich Extract Made From New Zealand Blackcurrants for 5 Weeks Supports Exercise Recovery Through the Management of Oxidative Stress and Inflammation: A Randomized Placebo Controlled Pilot Study

“…In a previous study by us, we found that following the single consumption of a New Zealand blackcurrant anthocyanin-rich extract (BAE, containing >0.8 mg/kg total anthocyanins) that the anthocyanins were first detectable in plasma 1 h following consumption. Utilizing these findings we found in a subsequent exercise intervention trial that consumption of BAE (containing >1.6 mg/kg total anthocyanins) 1 h prior to a 30 min moderate exercise indeed attenuated oxidative stress and supported innate immunity (41).…”

“…Individuals participating in the exercise trial were also excluded if they were unable to perform the 30 min rowing exercise (e.g., current injury or recovering from injury received within the last 3 months). Participants selected for this study showed similar moderate daily physical activity scores on the Baecke questionnaire as described in our previous BAE study (41).…”

“…The BAE extract displayed a high inherent antioxidant capacity (oxygen radical absorbance capacity [ORAC]; 6,424, ferric reducing ability of plasma [FRAP]; 3,810 µM Trolox equivalents) compared to other berryfruit (43), which is due to its high anthocyanin content as the extract contained <1 mg/100 g of vitamin C. In this current study, we selected to use a dose of BAE (equ. 240 mg total anthocyanins or 3.2 mg/kg) that was greater than the reported minimal effective dose (41) and has been previously repeatedly shown to facilitate recovery from exercise-induced oxidative stress (39,41). The dose of extract used aligns well with a typical dietary serving and equates to ∼48 g of blackcurrant fruit and 14 mL of blackcurrant juice concentrate (65Brix).…”

“…A sugar (glucose) placebo (PLA) which was also encapsulated and matched to the sugar content of the extract was used. This PLA was selected to exclude any possible acute increases in plasma antioxidant capability being due to sugar metabolism (44) and has been used in previous nutrition exercise intervention trials by us and others (39,41,45).…”

“…The study design is based upon a previous trial examining the time-and dose-dependent efficacy of pre BAE consumption on exercise recovery (41). A double-blind placebo-controlled trial design consisted of two groups: PLA or BAE extract consuming the equivalent of 3.2 mg/kg total anthocyanins.…”