New Zealand Blackcurrant, Fat Oxidation and Recovery with Dr Matthew Cook

Save 20% on all Nuzest Products WORLDWIDE with the code MIKKIPEDIA at www.nuzest.co.nz, www.nuzest.com.au or www.nuzest.com
Curranz Supplement: Use code MIKKIPEDIA to get 20% off your first order - go to www.curranz.co.nz  or www.curranz.co.uk to order yours

NZ listeners - save 10% off Calocurb by using the code Mikkipedia10 at www.calocurb.co.nz

Episode Summary
Dr Matthew Cook is a Senior Lecturer in Sport and Exercise Science at the University of Worcester in the UK. He completed the first PhD examining the effects of New Zealand blackcurrant on physiological responses at rest and during exercise in trained cyclists, under Prof Mark Willems at the University of Chichester, and he is still researching blackcurrant and performance, recovery and health. Mikki has used CurraNZ for years, including during the Grand to Grand Ultra, and wanted to hear from one of the researchers behind the evidence. Matt explains what is in New Zealand blackcurrant, why his group thinks the metabolites formed after we eat anthocyanins matter more than the anthocyanins themselves, and how an extract compares with eating the whole fruit.
The centre of the conversation is Matt's recent meta-analysis of 15 studies and 226 participants, which found a consistent increase in fat oxidation during exercise. Matt is careful about the size of it: about 0.042 grams of fat a minute, or roughly 2.5 to 3 grams over an hour of moderate exercise, "physiologically detectable" and possibly meaningful, but modest. He also notes that more fat use does not automatically mean glycogen sparing. They talk about why some people respond more than others, including a study where women with more body fat responded more (an observation in 11 women that needs repeating), and how little is known about perimenopausal, menopausal or insulin-resistant women. Matt finishes with the most-studied dosing protocol, timing before events and the evidence on recovery.
Key Topics
  • Matt's path from an undergraduate degree at Southampton Solent University to a master's and PhD at the University of Chichester, and his ongoing collaboration with Prof Mark Willems
  • What makes New Zealand blackcurrant distinctive: high UV exposure, an anthocyanin profile dominated by delphinidin and cyanidin, and the idea that metabolites made in the liver and by gut bacteria drive the effects
  • Whole fruit versus extract: two capsules (600 mg) give about 210 mg of anthocyanins, roughly 70 to 80 g of fresh fruit by Matt's rough calculation, with seasonality, consistent dosing and fibre load favouring an extract
  • The consistent finding that blackcurrant shifts fuel use towards fat at the same exercise intensity, and why that does not automatically equal glycogen sparing
  • Matt's meta-analysis of 15 studies and 226 participants: a pooled increase in fat oxidation of 0.042 g per minute, about 20 kcal over an hour, and why percentage changes can look larger than they are
  • A study of 11 men and 11 women: both increased fat use, but only in women did the size of the response track body fat percentage, an observation Matt says needs repeating
  • Research gaps in women across the lifespan, including perimenopause, menopause, insulin resistance and higher body fat, since most participants so far have been men or lean, active women
  • Responders and non-responders: people burning more carbohydrate at baseline (a higher RER) had more room to respond, and why a smartwatch cannot measure RER
  • A Liverpool John Moores University muscle biopsy study showing greater use of fat stored inside type 1 muscle fibres, and what that might mean beyond athletes
  • Practical dosing: 600 mg a day split morning and evening, starting seven days before an event, two capsules about two hours before the start, practising in training first, and some evidence for taking it for a few days after damaging exercise to help recovery
Chapters
00:00 Introduction
03:53 Matt's background and blackcurrant research
09:53 Anthocyanins, metabolites and the gut
18:20 Whole fruit versus extract
24:28 Fat oxidation during exercise
27:39 Putting the meta-analysis effect in context
31:59 Men, women and body fat
36:48 Responders and non-responders
40:22 Baseline fuel use and RER
43:18 Muscle fat use and metabolic health
50:43 Dosing, timing and recovery
54:29 Upcoming research and contact details
Guest / Resources
  • Dr Matthew Cook, University of Worcester: worcester.ac.uk/discover/matthew-cook.html. Matt says his email address and papers are listed on this page, and he would like to hear from people and coaches who have used blackcurrant
  • Cook MD, Bateman JJ, Willems MET. Blackcurrant Anthocyanin Supplementation Alters Exercise-Induced Substrate Utilization - A Systematic Review and Meta-Analysis. Journal of Dietary Supplements, 2026: doi.org/10.1080/19390211.2026.2624114
  • Cook MD, Shan Y, Willems MET. Effects of New Zealand Black Currant Extract on Exercising Substrate Utilization and Postexercise Blood Pressure in Men and Women. International Journal of Sport Nutrition and Exercise Metabolism, 2025: doi.org/10.1123/ijsnem.2024-0108
  • Willems MET, Cook MD. Alterations of Exercise-Induced Carbohydrate and Fat Oxidation by Anthocyanin-Rich New Zealand Blackcurrant Are Associated with the Pre-Intervention Metabolic Function: A Secondary Analysis of Randomized Crossover Trials. Nutrients, 2025: doi.org/10.3390/nu17060997
  • The Liverpool John Moores University muscle biopsy study: Jones LA, Leung L, Barrett JS, Fortis HO, Strauss JA, Shepherd SO. New Zealand blackcurrant extract augments muscle glycogen storage at rest and enhances intramuscular triglyceride degradation during prolonged exercise. European Journal of Applied Physiology, 2026: doi.org/10.1007/s00421-025-05995-9
  • Prof Mark Willems, University of Chichester, Matt's PhD supervisor and long-time collaborator
  • CurraNZ, the New Zealand blackcurrant extract used in this research, is a sponsor of the show. Use the code MIKKIPEDIA for a discount: curranz.co.nz
  • Mikki's earlier episodes with Fleur Cushman of CurraNZ, including Fleur Cushman - the science behind blackcurrants