the heart-healthy ‘super fruit’ that improves 5K performance like a ‘super shoe’ at a fraction of the price:

The Heart-Healthy ‘Super Fruit’ that Improves 5K Performance Like a ‘Super Shoe’ – at a Fraction of the Price

Heart-healthy blackcurrant extract can make 5K runners go ‘impressively’ faster by 38 seconds and offers a cost-effective option versus £200+ performance ‘super shoes’, or so claim CurraNZ (which I’ve used for years in my training).

The recent study (1) revealed that the berry boosts average 5K running times by a startling 38 seconds. The berry extract improved performance to the same degree as many months of training – and within two hours of popping the pills.

With six million runners in Britain, the sport is the most popular form of fitness in the UK (Statista), because of its high accessibility, low cost and simplicity. Recently there has been a flight to 5K in Britain, thanks to the hugely popular Parkrun and the NHS-designed-and-recommended fitness program, Couch to 5K. The format is favoured by experts as an easy way to promote healthy living through exercise and socialisation.

Blackcurrants are high in natural antioxidant-rich bioactives called anthocyanins that widen blood vessels (2-4), improve arterial function (5) and boost the blood pressure-lowering effects of recovery exercise (6). Blood flow is critical for working muscles and athletic performance.

In this study, the University of Chester tested trained recreational male runners and triathletes after they took 3 x 300mg capsules of CurraNZ® blackcurrant extract – containing a total of 315mg of anthocyanins – two hours before the 5km treadmill test. Findings showed faster completion times in 88% of respondents, with average improvements of 38 seconds compared to placebo, and individual responses up to 5.7%.

Dr Samantha Moss, Senior Lecturer in Physiology and Sports Sciences at the University of Chester, who led the CurraNZ study, said:

We were surprised to see the differences in running times between the conditions. The novelty is that New Zealand blackcurrant supplement can be used as a performance-enhancing aid on an acute basis, which may suit many recreational athletes preparing for a race.

Running expert Dr Stefanie Flippin, advisor to CurraNZ, emphasized the significance of these findings:

An average improvement of 38 seconds over 5km is enormous. Faster completion times over shorter distances are harder to achieve and require months – sometimes years – of training. This scale of improvement is impressive.

Previous studies have shown that a seven-day intake of 1-2 capsules (300 mg-600 mg) of CurraNZ is required to improve cycling and running times. These improvements are linked to changes in cardiovascular and metabolic function. However, the faster running times in this study were achieved without significant changes to carbohydrate oxidation, fat oxidation, heart rate, blood lactate or rating of perceived exertion.

As Dr Moss noted:

Based on previous studies, we believe these changes might be due to an increase in blood flow, which can enhance lactate clearance.

Further research on the role of blackcurrant extract anthocyanin metabolite profiles may provide insights into the mechanisms.

CurraNZ® is derived from New Zealand blackcurrants, renowned for their exceptionally high levels of anthocyanins and polyphenols. These bioactive compounds, encapsulated in each 300mg capsule, provide a standardized dose of Enzans™, offering athletes a natural edge in their pursuit of excellence. CurraNZ® retails at £23.99 for a pack of 30 capsules.

code: 5KRUNNER20 for 20% off

FYI: Unpaid, free samples received that I use because I think they work.


  1. The effects of an acute dose of New Zealand blackcurrant extract on 5 km running performance Int J Sport Nutr Exerc Metab Samantha L. Moss1, Edward Brindley1, Kevin Enright2, Jamie Highton1 & Richard Bott1 2023
  2. Cardiovascular function during supine rest in endurancetrained males with New Zealand blackcurrant: a dose-response study, Eur J Appl Physiology DOI 10.1007/s00421-016-3512-x
  3. Effect of Intake Duration of Anthocyanin-rich New Zealand Blackcurrant Extract on Cardiovascular Responses and Femoral Artery Diameter during Sustained Submaximal Isometric Contraction, Journal of Dietary Supplements, 2021,
  4. New Zealand Blackcurrant Alters Physiological Responses and Femoral Artery Diameter during Sustained Isometric Contraction. June 2017 Nutrients 2017, 9(6), 556; doi:10.3390/nu9060556
  5. Effects of blackcurrant extract on arterial functions in older adults: A randomized, double-blind, placebo-controlled crossover trial, Clinical and Experimental Hypertension on May 13, 2020.
  6. New Zealand Blackcurrant Increases Post-Exercise Hypotension Following Sustained Moderate Intensity Exercise, International Journal of Sports Nutrition, Y Shan, M Cook, Int J Sport Nutr Exerc Metab. 2023 Jul 6;1-9. doi: 10.1123/ijsnem.2023-0014.

More claims and related science here.

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