The effect of New Zealand blackcurrant on sport performance and related biomarkers: a systematic review and meta-analysis

Abstract

Background Blackcurrants have come to be regarded as a superfood because of their high polyphenol content, namely anthocyanins. While many berry types have been studied, blackcurrant-anthocyanins may be the superior berry when it comes to athletic performance. The purpose of the review was to evaluate the effects of blackcurrant supplementation on athletic performance, oxidative markers, cognition, and side effects. Methods Systematic review and meta-analysis. Review manager software (version 5.3) was used for the meta-analysis. The risks of bias was independently assessed using the guidelines and criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions. The data sources for the search included MEDLINE (Ovid), Google Scholar databases, additional references lists, conference proceedings and grey literature until August 2019. Eligibility Criteria included all blackcurrant (New Zealand derived) interventions, randomised control trials, human participants, placebo-controlled only. Results A total of 16 separate studies met the criteria for inclusion in the systematic review, with 9 studies contributing to this sport performance meta-analysis. There was an improvement in sport performance when supplementing with blackcurrant, 0.45 (95% CI 0.09–0.81, p = 0.01). The effective dose appears to be between 105 and 210 mg of total blackcurrant anthocyanins, prior to exercise. There were insufficient studies reporting oxidative markers, cognitive effects or biomarkers, and/or side effects to comment on the mechanism of action. Conclusion Blackcurrant has a small, but significant, effect on sport performance, with no known detrimental side effects.

Correction to: The effect of New Zealand blackcurrant on sport performance and related biomarkers: a systematic review and meta-analysis

“…The original article contains numerous errors [ 1 ] of which the corrections are detailed below: A further review questioned whether the authors should include a further publication, Willems et al 2019 [ 2 ]. The authors highlight that in the early additions of the manuscript Willems et al 2019 [ 2 ] was included, however one of the original reviewers stated the trial was conducted under non-normal oxygen conditions and as such should be excluded from the pooled analysis.…”

Improved Endurance Running Performance Following Haskap Berry (Lonicera caerulea L.) Ingestion

“…According to independent analysis of the HB, the anthocyanin content was ~24.9 mg/g, (~150 mg/dose). The dose and duration are consistent with previous studies examining the effects of anthocyanin-rich foods on exercise performance [39]. To maintain blinding, participants were told the research was investigating the effects of a freeze-dried berry where 6 g of the food was pre-weighed and provided to participants in sealed sachets, along with enough yoghurt for the intervention period.…”

Efficacy of Popular Diets Applied by Endurance Athletes on Sports Performance: Beneficial or Detrimental? A Narrative Review

“…Polyphenols containing flavonoids, phenolic acids, lignans, and stilbenes are the most diverse non-nutrient group of phytochemicals that are produced as secondary metabolites throughout plants and have a broad spectrum of effects on metabolic health [ 77 ]. Polyphenol research of the athletic population has often been conducted using various fruits and vegetables, mainly berries [ 78 ], including blueberries [ 79 , 80 , 81 , 82 ], black currant [ 83 ], Montgomery cherry [ 84 , 85 ], and pomegranate [ 86 ]. Acute polyphenol intake or supplementation of ~300 mg 1–2 h before training or >1000 mg of polyphenol supplementation (equivalent to 450 g blueberries, 120 g blackcurrants or 300 g Montmorency cherries) 3 to more days (1–6 weeks) before and immediately after training is recommended as a countermeasure to improve antioxidant and anti-inflammatory response mechanisms [ 87 ].…”