Research Papers

Effect of New Zealand Blackcurrant Extract on Muscle Fibre-Specific Fatigue

SYNOPSIS: RESEARCHERS from the University of Chichester examined the effect of a week’s daily intake (600mg) of New Zealand blackcurrant extract on muscle fibre-specific fatigue. Twelve males performed a fatiguing protocol including voluntary and electrical isometric contractions to identify their predominant muscle figure type  and measure maximal muscle twitch responses.

The abstract, released at the European Conference of Sport Science in July, found:

  • Individuals with Type 1 fibres (slow twitch) had an increased resistance to fatigue
  • Individuals with Type 2 fibres (fast twitch) could produce 15% greater force during the initial stages of the 16-set contractions
  • Blackcurrant may be beneficial for individuals performing high-intensity, repeated exercise and those undertaking endurance exercise modalities

To read the poster abstract, click here

Effect of New Zealand Blackcurrant Extract on Sports Climbing Performance

SYNOPSIS:RESEARCHERS from the University of Chichester performed a performance study in a group of 20 experienced graded climbers of mixed abilities.

The study found following seven days’ intake of 600mg CurraNZ blackcurrant extract capsules:

  • Increased hang time 8%
  • Increased climb duration 11% between climbs one and three, the point at which the control group experienced a 23% decrease in climb duration

Rock climbing creates a high workload on the forearm flexors and increases reliance on blood flow during the short recovery periods. Blackcurrant has been shown to increase forearm blood flow (Matsumoto et al, 2005) and increase femoral artery diameter during submaximal isometric contraction (Cook et al, 2017).

Researchers concluded that NZBC extract significantly improves sports climbing endurance and maintained climbing ability at periods when participants in the placebo condition were experiencing a marked decline in performance.  

To read the poster abstract, click here

Dietary Anthocyanins: A Review of the Exercise Performance Effects and Related Physiological Responses


Anthocyanins are pigments within berries and other colourful fruits and vegetables. They have anti-oxidative and anti-inflammatory actions that improve recovery from exercise. Furthermore, anthocyanins can also have vasoactive properties, including decreasing mean arterial blood pressure and increasing vasodilation during exercise. This narrative review focuses on the experimental evidence for blackcurrant and cherry anthocyanins to improve exercise performance in humans, which may be fruit and/or berry specific.

Conclusion: Performance benefits have been observed following blackcurrant ingestion, whereas performance improvements following intake of other anthocyanin containing fruits have not been demonstrated to the same extent. This may be due to the individual and specific anthocyanin make-ups within the fruits.

To read the paper, click here

New Zealand blackcurrant extract enhances fat oxidation during prolonged cycling in endurance-trained females

Synopsis: This study by Liverpool John Moores University tested the effect of CurraNZ in 16 endurance-trained women during 120 minutes cycling at 65% VO2max after seven days intake of 600mg (two capsules) of the blackcurrant extract supplement.


Results showed:

  • An average of 27% increase in fat oxidation (burning)
  • Participants showed increases of up to 55%
  • Decreased carbohydrate oxidation of 12%
  • Resulting improvements to fat burning proved equivalent to undertaking endurance exercise every day for three-four weeks
  • Increased pre-exercise fatty acids and glycerol concentrations, suggesting that blackcurrant improves resting fat oxidation rates
  • Potential to deliver a greater degree of fat burning in overweight, obese and unhealthy people


To read the paper, click here

Blackcurrant Alters Physiological Responses and Femoral Artery Diameter during Sustained Isometric Contraction

Synopsis: This study tested the effect of CurraNZ on femoral artery diameter and cardiovascular responses during 30% isometric maximal voluntary contraction of the quadriceps muscle and produced high-impact results. Muscle blood flow is critical for oxygen delivery and resulting muscle function, as well as improved performance due to reduced fatigue. Results showed:

  • 20-35% increased blood flow was observed due to the vasodilatory actions (widening of blood vessels) of CurraNZ. The blackcurrant extract created a 6.9%- 8.2% increase in femoral artery diameter.
  • Blood pressure was 7-12% lower during muscle contraction, indicating cardiovascular system experienced less stress.
  • Muscle fibres demonstrated 11-16% less activity: indicates muscles worked to the same intensity with reduced stress.
  • Cardiovascular responses include increases to cardiac output and stroke volume by 16% and 11%, and reductions of total peripheral resistance by 25%.
  • Reduced fatigue was observed as a result of increased blood flow, higher total haemoglobin and enhanced uptake and utilization of oxygen in the muscle. As a result, the muscle didn't work as hard
  • Subjects had higher total haemoglobin, enhanced uptake and utilization of oxygen in the muscle, which led to reduced fatigue. As a result, the muscle didn't work as hard
To read the paper, click here
Effect of New Zealand Blackcurrant on Performance during the Running Based Anaerobic Sprint Test in Trained and Recreational Football Players


  • Study tested 600mg NZBC on 15 recreational and nine Professional Academy Youth football players to investigate whether blackcurrant extract would improve performance during repeated, high-intensity sprints 
  • Blackcurrant had a clear effect on the trained players, who experienced less slowing in the sprint tests
  • Trained footballers had reduced slowing of sprint times, an effect not observed in the non-elite players
  • 12 of the 24 players (including five of the nine Academy players) demonstrated a lower fatigue index by a combined absolute value of 12%, calculated on the change in maximum power to the slowest sprint
  • Trained footballers benefited more from New Zealand blackcurrant extract supplementation in exhaustive running test with long recovery times
Published September 2017: Sports5(3), 69; doi:10.3390/sports5030069
New Zealand Blackcurrant improves cycling performance and fat oxidation in cyclists
  • CurraNZ blackcurrant extract improved 16.1 km time trial performance by 2.4% (mean) with improvements up to 8.6%.
  • CurraNZ improved fat oxidation up to 27% at moderate exercise intensity
  • CurraNZ blackcurrant extract improved cycling speed in the last 75% of the 16.1 km time-trial.
  • CurraNZ allowed athletes to tolerate higher concentrations of blood plasma lactate 
Published, European Journal of Applied Physiology, 2015
    Dose Effects of New Zealand Blackcurrant Extract on Substrate Oxidation and Physiological Responses during Prolonged Cycling


    • Fat oxidation at ~65% Vo2max in trained cyclists by intake of New Zealand blackcurrant extract for 7 days exhibited a dose-dependent response
    • During 120 minutes of cycling at ~65% Vo2max, NZB extract increased fat oxidation by 17.5%, 22% and 24% for 300mg, 600mg and 900mg
    • During 120 minutes cycling ~65% Vo2max, NZB extract decreased carbohydrate oxidation by up to 11.5%
    • Scientists excited at the degree to which blackcurrant increased fat oxidation in trained individuals with already existing metabolic adaptations
    • Participants burned an extra 116 calories as a result of blackcurrant extract's influence on fat metabolism in higher-dose groups
    Cardiovascular Function During Supine Rest in Endurance-Trained Males with New Zealand Blackcurrant: A Dose-Response Study


    • Dose-response study investigating cardiovascular responses in cyclists at rest, with 300mg, 600mg, 900mg NZB extract
    • Results showed NZB extract had a moderate to large effect on CV responses
    • Responses varied between doses, highest at 900mg
    • Extract reduced total peripheral resistance by 20.2% (900mg)
    • Increased cardiac output 27.5% (900mg)
    • Increased stroke volume 17.7% (900mg)
    • Effect on blood volume pumped may enhance post-exercise recovery in athletes
    • May be beneficial for clinical populations affected by reduced circulation
    Published, European Journal of Applied Physiology,December 2016
      Read more about the study
      Metabolic and Physiological Responses by New Zealand Blackcurrant during Cycling: A dose-response study


      • Respiratory Exchange Ratio decreased 2.49% / 2.48% for 600mg and 900mg/day
      • Change indicated enhanced fat oxidation
      • Increased fat oxidation by New Zealand blackcurrant extract may enhance performance
      Abstract selected for special thematic session at the 2016 American College of Sports Medicine Conference, Boston
        New Zealand blackcurrant may assist sports recovery and immunity
        • Assists the natural benefits of exercise
        • Controls oxidative stress and inflammation
        • Assits immune protection - enhanced immunity
        • Speedier tissue repair, recovery and performance
        • Train/work harder and for longer
        Plant & Food Research Institute: NZ Blackcurrant for Sports Performance
        • Blackcurrant consumption modulates exercise-induced oxidative stress and inflammatory responses
        • NZBC extract, exhibiting both antioxidant and anti-inflammatory properties, if ingested at appropriate amounts and at the appropriate time, may enhance exercise-induced health benefits
        • Long-term consumption of NZBC anthocyanins may activate adaptive antioxidant and immune modulatory mechanisms.
        Published in the American Journal of Physiology, 2009 
          Beneficial physiological effects of New Zealand blackcurrant intake on Endurance Athletes
          • Delayed OBLA, complete shift of the lactate curve, which may have beneficial implications for endurance athletes as it would allow prolonged high intensity exercise during competition and endurance exercise training
          • Lower lactate of 13% and increased power at maximum oxygen uptake
          • Up to 27% lower lactate across all cycling intensities
          • Conclusion: Observations suggest increased lactate clearance
          • The delay in OBLA could be predictive for an enhancement of cycling endurance performance
          Published, Journal of Human Kinetics, 2015
          New Zealand Blackcurrant Extract Improves High-Intensity Intermittent Running


          • CurraNZ blackcurrant extract improved distance covered during sprints by 10.6%, or 411m (mean)
          • 1 in 3 subjects improved more than 15%.
          • A trend towards higher lactate at exhaustion
          • Participants showed increased lactate clearance up to 30 minutes post exercise, showing improved recovery

          Paper published in the International Journal of Sports Nutrition and Exercise Metabolism

          Read more about this trial

          Beneficial Effects of New Zealand Blackcurrant Extract on Maximal Sprint Speed during the Loughborough Intermittent Shuttle Test


          • Study assessed whether NZBC could help athletes maintain the performance of repeated maximal sprints in field sports, especially in latter stages of game
          • Eight of 13 participants had higher running times to exhaustion after consuming CurraNZ
          • Those participants who increased time to exhaustion did so by on average 15%
          • NZBC intake allowed for better maintenance of the fastest sprint time during LIST
          • Participants tolerated higher heart rate values and ran for longer at higher intensity
          • Particpants showed reduced slowing of the fastest sprints at exhaustive stages
          Published: August, 2016, Special Issue: Sport Nutrition for Health and Performance
            Effects of Blackcurrant Anthocyanin Intake on Peripheral Muscle Circulation in during Typing Work in Humans
            • Blackcurrant anthocyanin increases resting blood flow
            • Prevents decrease in muscle oxygenation that occurs during exercise
            • Increases production nitric oxide
            • Increases arterial flow to muscle tissue
            • Reduces workload on muscles due to increase blood flow and oxygen supply
            • Facilitates removal of unfavorable metabolites (lactic acid, free fatty acids, etc)
            • Prevents hypoxia and disturbance of oxidative metabolism in muscles
            Published, European Journal of Applied Physiology, 2005
              Polyphenolic phytochemicals – just antioxidants or much more?
              • Protects cells from oxidative stress, which leads to intracellular imbalanced DNA lesions (thus inhibiting DNA damage)
              • Polyphenols reduce oxidative stress by antioxidant enzymes
              • Polyphenols act as inflammatory modulatory agents by inhibiting the inflammatory signalling cascades
              • Increases the cells' ability to scavenge ROS* produced in inflammatory processes.
              Effect of New Zealand Blackcurrant Extract on Repeated 4km Time Trial Cycling Performance


              • Berry extract improved mean times by 0.82%
              • Seven out of ten cyclists improved power outputs
              • Subjects saw improved times through mid-sections of 4km time trials
              • Study shows New Zealand blackcurrant has small performance effect in short-duration, high-intensity exercise model

              Read the peer-reviewed, published paper here