Countless researches have been showing the health benefits of complimenting your diet with berries. Blackcurrant (Ribes nigrum) has been shown to have the highest concentration of the polyphenol anthocyanin. Polyphenols naturally occur in plants (hence, called phytochemicals) and they are responsible for the coloring in plants. Polyphenols also protect plants from the attack of insects and diseases caused viruses, fungus and bacteria.
In humans, anthocyanins have shown to work as anti-inflammatory and antioxidant (Pojer et al. 2013). A research carried out with people who spend long hours in a sitting position showed that, after blackcurrant intake, these people had an increased blood flow in their extremities (Matsumoto et al. 2005) due to increased vasodialation and vasorelaxation probably induced by the anthocyanins in blackcurrant (Ziberna et al. 2013).
Although previous studies on New Zealand blackcurrant 7-day-intake during exercise showed no significant effect on exertion levels during high-intensity treadmill running sprints (Perkins et al. 2015) or during cycling (Willems et al. 2015), other studies demonstrated that NZBC extract intake during and after prolonged exercises does have a significant effect on muscle recovery (Cook et al. 2015; Perkins et al. 2015) and reduced after-workout soreness (an increase in lactate threshold; Willems et al. 2015). In addition, higher fat oxidation rate was detected during a 10-minute cycling (Cook et al. 2015).
In their June 2017 paper, Cook and associates show the results of yet another trial on the effects of NZBC extract intake this time at the physiological level: what happens inside our bodies when we have New Zealand Blackcurrant in our diets.
Cook et al. (2017) have demonstrated that fat oxidation and carbohydrate oxidation rates are strongly affected by the anthocyanins present in NZBC. The physiological responses that influence fat oxidation vary depending on the duration of the exercise. As written by the researchers: fatty acid translocase/cluster of differentiation 36 (FAT/CD36) on the mitochondrial membrane is increased at 120 min after exercise, but not after 30 min (Holloway et al. 2006). In addition, prolonged cycling exercise causes a gradual decrease in insulin concentration, a gradual increase in plasma free fatty acid and glycerol concentration (Jeukendrup et al. 1999), and a lowering of intramuscular glycogen stores (Vøllestad and Blom 1985). Therefore, the substrate oxidation and the physiological responses may be different with NZBC during prolonged exercise of 120 min, to those reported during shorter duration steady state exercise.
However, as demonstrated by Cook and associates, the positive physiological effects of NZBC anthocyanins are also dose-dependent. Even though previous studies have shown the effectiveness of NZBC intake during exercises, whether the physiological responses were dose-dependent had yet to be demonstrated. This is what pushed Cook and fellow researchers to carry out their next study, to examine if dose-dependent changes in physiological responses occur following New Zealand blackcurrant taken for 7 days during prolonged cycling in trained cyclists.
Fifteen healthy participants were selected for the experiment who were asked to take one NZBC capsule a day, 12-hours apart, for 7 days. Then, in the lab, participants were asked to cycle for 120 minutes, whilst several physical and physiological responses were measured every 15 minutes (for online article’s abstract click here).
Cook et al. (2017) is the first study to demonstrate the dose-dependent effect of New Zealand Blackcurrant extract intake on fat oxidation during exercise (120-min cycling in trained male cyclists). The researchers found an increase in fat oxidation with an increased dosage of NZBC extract intake. The authors, however, highlight that the increased fat oxidation rate found in this study was higher than that found by Cook et al. (2015) probably because of increased exercise duration and intensity compared to the earlier study (30-min cycling). The dosage of NZBC extract used in their 2017 study was also three times higher than what they used in their previous study (600 to 900 mg/day compared to 300 mg/day in 2015). The gradual increase in fat oxidation during exercise following 600 mg/day to 900 mg/day of NZCB extract intake could be linked to the gradual increase of anthocyanin intake by the body, the authors say.
Cook and associates highlight that the results found in their June 2017 study showed dose-dependent changes in fat oxidation rates in the participants: “The results in this study with NZBC indicate similar dose-dependent changes, as it appears that there may be a minimum NZBC dose required to elicit physiological effects. For example, fat oxidation was only increased after 600 mg day−1 (210 mg day−1 anthocyanin) and 900 mg day−1 (315 mg day−1 anthocyanin), with no difference between 600 and 900 mg day−1.”
Although anthocyanins have poor bioavailability (the proportion of a drug or other substance which enters the circulation when introduced into the body and so is able to have an active effect), several studies have observed that anthocyanin metabolites were detected in the blood 48-hours after intake (Kay et al. 2005). Cook et al. (2017) seem to demonstrate the power of a 7-day intake of anthocyanin and its capacity of building up in the body. Therefore, a continuous, daily supplementation of New Zealand Blackcurrant extract (in capsules, for instance) may strongly increase and prolong the already demonstrated physiological benefits of natural anthocyanins.
This article was produced with the authors’ permission. It is a short description of what has been published by Cook and associated in their June 2017 paper: Cook, M. D., Myers, S. D., Gault, M. L., Edwards, V. C., & Willems, M. E. T. (2017). Dose effects of New Zealand blackcurrant on substrate oxidation and physiological responses during prolonged cycling. European Journal of Applied Physiology, 117(6), 1207-1216.
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