Research Papers

Effects of daily and intermittent intake of CurraNZ blackcurrant extract on cardiovascular responses during moderate intensity exercise in males

New Zealand Blackcurrant extract boosts exercise-induced cardiovascular function and lowers blood pressure during 30 minutes of brisk walking. 

  • 15 participants on CurraNZ blackcurrant extract experienced a 6% reduction to diastolic blood pressure after 7 days, which increased to 11% after 14 days of daily use
  • A 14% reduction in total peripheral resistance after 14 days continuous intake
  • Mean arterial pressure (average blood pressure measurement) reduced by 7% after 14 days, but had no significant effect after 7 days
  • 9% increase to cardiac output at 7 and 14 days
  • 10% increase to stroke volume after 14 days
Consumption of New Zealand Blackcurrant Extract Prior to Exercise May Assist Recovery from Oxidative Stress and Maintains Neutrophil Function: A Pilot Study

The study, involving 36 subjects, evaluated consumption of 34% NZ Blackcurrant extract on time- and dose-dependent plasma anthocyanin bioavailability and its potential in promoting recovery from exercise-induced oxidative stress and maintenance of circulating neutrophils. 


  • Single intake of blackcurrant extract reduced exercise-induced oxidative stress markers by up to 34%
  • Blackcurrant extract preserved circulating neutrophil function, reducing the risk of opportunistic infection
  • Doses equivalent to the ranges found in one and two capsules of CurraNZ took two hours to peak in the blood stream and facilitated recovery from exercise

To view the published study, click here

Effects of CurraNZ blackcurrant extract on whole-body fat oxidation during moderate intensity exercise in males

SYNOPSIS: Researchers from the University of Chichester examined the dosing and duration effects of New Zealand Blackcurrant extract on fat oxidation during brisk walking.

Under controlled conditions, participants took 600mg of CurraNZ every day for two weeks. The subjects performed a 30-minute moderate-intensity walking test at day 7 and day 14, in which their use of fat and carbohydrate were measured.

The study showed:

  • An average of 10% increase in fat oxidation after week one
  • An average 16% increase in fat oxidation (fat burning) after week two
  • No effect on fat oxidation when taken intermittently (every second day)
  • Blackcurrant clearly favours fat as an energy source after longer intake
  • The potential to deliver a greater degree of fat burning in overweight, obese and unhealthy people

Conclusion: Previously it was not known whether daily intake of New Zealand blackcurrant extract CurraNZ was required for its effectiveness, with this study confirming that longer intake is better and blackcurrant helps the body rely on fat as an energy source if taken every day.

The abstract was presented at the International Sports and Exercise Nutrition Conference in Newcastle, UK, in December 2018. Click here to read the poster

CurraNZ blackcurrant extract enhances fat oxidation during submaximal exercise in the heat

SYNOPSIS: Compared to normal temperatures, the body burns less fat and more carbohydrate when exercising in the heat. Previous studies have shown that New Zealand blackcurrant extract CurraNZ increases rates of fat burning at low and moderate intensities when exercising in normal temperatures.

Researchers at the University of Chichester examined whether New Zealand blackcurrant anthocyanin extract would affect substrate use during moderate intensity exercise in the heat.

Twelve unacclimatised men and six women took 600mg of CurraNZ New Zealand blackcurrant extract for seven days before performing 60 minutes of treadmill running in hot ambient conditions (34°C, 40% humidity).

The findings showed:

  • Blackcurrant increased fat oxidation by on average 30% compared to the placebo group under the conditions


Conclusion: The study findings suggests that blackcurrant is somehow counteracting the decline that occurs to fat oxidation during exercise in the heat.

CurraNZ blackcurrant extract attenuates enterocyte damage following exertional heat stress

SYNOPSIS: University of Chichester researchers examined whether CurraNZ blackcurrant extract can help athletes reduce the risk of gastro-intestinal stress during exercise in the heat.

Twelve unacclimatised men took 600mg of CurraNZ for seven days before performing 60 minutes of moderate-intensity treadmill running in hot ambient conditions (34°C, 40% humidity).  Measurements were taken of intestinal fatty acid binding protein, a marker of enterocyte damage, at rest and 20, 60 and 240 minutes post-exercise.

The findings showed:

  • Robust evidence that blackcurrant helps reduce heat exertion-induced gastro-intestinal damage

Conclusion: Blackcurrant extract exerted a significant reduction in this marker of intestinal cell damage at each post-exercise time point, indicating blackcurrant helps maintain intestinal integrity.

Intra-individual responses to CurraNZ blackcurrant extract during high-intensity, intermittent running? A repeat response study

SYNOPSIS: Researchers examined whether CurraNZ Blackcurrant extract can consistently enhance running performance on repeated occasions after using two capsules of the CurraNZ supplement for a week.

The University of Chichester study investigated whether individuals would experience a variation of responses to the berry supplement, which is common with most sports supplements.

Sixteen active males performed a high-intensity, intermittent treadmill running test following seven days’ loading on 600mg CurraNZ extract or placebo across five testing sessions.

The findings in the randomized, double-blind crossover design study showed:

  • 38% of participants were consistently high responders up to 37.8%
  • Six of the 16 subjects improved their total distance from 8.3% up to 37.8% across both blackcurrant trials
  • Nine participants improved their total distance a minimum of 7.9% in at least one trial

Nine of the subjects consistently enhanced their performance on blackcurrant when repeatedly tested in the randomized trials. The study included periods of at least two weeks of washout, in which subjects did not use the supplement, before re-taking blackcurrant extract for a week and again showing enhanced performance outcomes, with high responders in 38% of individuals.

Blackcurrant responders improved their average total running distance by 262m– 394m and average sprint distance by 116m-265m compared to the placebo condition.

Conclusion: Blackcurrant is effective for individuals looking to consistently and repeatedly improve their performance in sports characterised by high-intensity intermittent running.

The study abstract, Intra-Individual responses to New Zealand blackcurrant extract during high-intensity, intermittent running: A repeat response studywas released at the International Sports and Exercise Nutrition Conference, Newcastle, December 2018. Click here to read the poster
New Zealand blackcurrant powder reduces a human body odour component in middle-aged and older adults

A University of Chichester study has found that New Zealand blackcurrant can help reduce skin emission (2-nonenal) that occurs as a result of oxidative stress – a process that usually starts from age 40 – and could prove an intervention for reducing ‘old person’s smell’.

The study was performed on 14 middle-aged adults, aged 49-64, who consumed New Zealand blackcurrant daily for seven days (132mg anthocyanin). A cap was fitted to capture skin gas emissions from the base of the neck.

Researchers measured 2-nonenal, which occurs as a result of breakdown of fats (lipid peroxidation) in glands under the skin.

The findings showed:

  • A 28% average reduction of 2-nonenal gas
  • Six participants showed reductions of more than 69%
  • Two participants had lower emissions of 80% and 82%

Conclusion: NZ blackcurrant is able to reduce 2-nonenal-induced body odour in adults.

The abstract was presented at the International Sports and Exercise Nutrition Conference in Newcastle, UK, in December 2018. Click here for the poster

The effect of acute New Zealand blackcurrant juice consumption on motivation to exercise

SYNOPSIS:Consumption of blackcurrant extract in healthy individuals prior to a cognitive challenge has been shown to improve cognitive performance and mood. Although the underlying causes are unknown, a change in neurotransmitter concentrations involved in motivation was detected. Since motivation is key to desire and adherence to exercise, researchers investigated whether consuming blackcurrant prior to exercise improved voluntary physical activity by increasing motivation.

40 healthy participants consumed either a NZ blackcurrant juice concentrate (3.9mg anthocyanins/kg bodyweight) or sugar-matched placebo. Participants then exercised on a treadmill at a semi-brisk walking pace (50% of estimated maximal heart rate) where information on time and distance walked was concealed. During the exercise, participant’s mood and perceived exertion were assessed. The exercise was stopped when participant’s mood scores became consistently negative or started to shown signs of fatigue.

The study showed:

  • Heart rate, blood lactate and oxidative stress were similar in both groups.
  • The blackcurrant group walked further in both mean time and distance
  • The blackcurrant group recorded a significantly higher number of ‘positive’ mood scores
  • A decrease in MAO-B activity in the blackcurrant group
  • Reduced plasma prolactin levels in the blackcurrant group compared to placebo

Conclusion: Consuming blackcurrant juice prior to exercise supports motivation and desire to exercise for longer. This may be through blackcurrant compounds modulating neurotransmitter levels (eg dopamine, serotonin, noradrenaline) during exercise that influence mood and motivation.

To read the abstract, click here


Effect of CurraNZ Blackcurrant Extract on Physiological Responses at Rest and during Brisk walking in Southeast Asian Men

SYNOPSIS: The University of Chichester has for the first time examined the effects of CurraNZ blackcurrant extract on fat oxidation and cardiovascular responses in Southeast Asian men during moderate-intensity brisk walking.

In a collaboration study between the University of Chichester (UK) and Mahidol University (Thailand), 17 Thai males (normal body weight) consumed two capsules (600mg) CurraNZ 35% blackcurrant extract daily for seven days before performing a 30-minute brisk walking treadmill test. They were then tested on fat oxidation and cardiovascular responses at rest and during exercise.

The paper, Effect of New Zealand Blackcurrant Extract on Physiological Responses at Rest and during Brisk Walking in Southeast Asian Men: A Randomized, Double-Blind, Placebo-Controlled, Crossover Study was published in the Journal NutrientsOctober 2018.

The results showed:

  • No effect on fat oxidation at rest or during exercise
  • A moderate-to-significant effect on cardiac responses during exercise
  • No effect on cardiac function at rest

Blackcurrant enhanced vasodilation during exercise, but not at rest, with participants showing 12% increases to both stroke volume and cardiac output, and 11% lower vascular resistance during exercise.

Previous University of Chichester studies on Caucasian men have shown the berry extract improves fat oxidation 21% during two hours cycling, 10% during 30 minutes brisk walking (seven days’ intake), with significant increases in cardiovascular responses at rest.

Conclusion: From these findings it can be concluded that New Zealand blackcurrant affects vasodilation in both low static activity in Caucasian men and moderate-intensity exercise in Thai men. It is possible that Southeast Asian males may have different intake and duration requirements in to activate metabolic and cardiovascular responses at exercise and rest.

Click here to read the paper

Effect of CurraNZ 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 CurraNZ 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 CurraNZ 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

CurraNZ 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

CurraNZ Blackcurrant Extract 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 CurraNZ Blackcurrant on Performance during the Running Based Anaerobic Sprint Test in Trained and Recreational Football Players


  • Study tested 600mg CurraNZ blackcurrant extract 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
CurraNZ Blackcurrant extract improves cycling performance and fat oxidation in cyclists
  • 300mg (1 capsule) 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 CurraNZ 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 CurraNZ 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 CurraNZ 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
          CurraNZ 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