A new systematic review and meta-analysis has revealed that the proprietary New Zealand blackcurrant extract, CurraNZ, can shift the body's fuel source during exercise towards fat.
Published in the Journal of Dietary Supplements, the analysis pooled data from 15 controlled human trials involving 226 participants.
All studies used the same proprietary, standardised New Zealand blackcurrant extract — CurraNZ — across cycling and treadmill‑based exercise in active men and women.
Results showed that the 35% blackcurrant anthocyanin extract increases fat oxidation during exercise by 0.042 g/min and decreases carbohydrate oxidation by 0.099 g/min compared with the control.
CurraNZ said that, extrapolating across a training week of five 60-90-minute sessions, this would amount to an extra 15-20 grams of fat burnt.
"CurraNZ doesn't just talk about fat‑burning — it delivers measurable, repeated changes in how the body uses fuel during exercise," said lead author, Dr Matthew Cook, Senior Lecturer in Sport and Exercise Science at the University of Worcester.
These are big, credible effects for a berry‑derived supplement, backed by multiple high‑quality human trials.
CurraNZ added that individual studies it conducted reported ~20-30% higher exercise fat oxidation versus placebo during cycling and running protocols at moderate intensities and up to 27% higher mean fat oxidation in a 120‑minute cycling test in trained females.
Resting data in men showed an average increase of ~21% in fat oxidation after 14 days of CurraNZ, with some individuals experiencing increases of up to 61%, mimicking the fat‑burning adaptations typically seen after 1-3 months of endurance training.
"These effects put CurraNZ in the same conversation as (and in some contexts ahead of) many established 'fat‑burning' ingredients – but without stimulants," added Dr Cook.
We're seeing consistent shifts toward greater fat use, both at rest and during exercise, in peer‑reviewed, placebo‑controlled trials.
The company stressed that the new meta‑analysis and underlying trials identify that the response to CurraNZ is not one‑size‑fits‑all, but that this was good news for consumers who struggled with fat burning.
In women, those with higher body fat mass showed larger increases in fat oxidation (up to 200%) when taking New Zealand blackcurrant extract and individuals who were more carb‑dependent during exercise (higher baseline RER) tended to experience bigger shifts toward fat use with CurraNZ.
For both athletes and everyday exercisers, that's a powerful message.
Research cited in the review indicated that anthocyanins from blackcurrants enhance the expression of genes associated with energy expenditure.
This process promotes greater utilisation of intramuscular triglycerides in type I muscle fibres, providing a biological explanation for the consistently observed increases in fat oxidation.
For endurance athletes, this translates into the following benefits:
- better preservation of limited glycogen stores
- stronger late‑race performance
- and a more efficient use of internal fat reserves during long events.
For active members of the general public, it supports training at fat‑max intensities, which are associated with reductions in body mass, total fat mass and abdominal fat.
Every trial in the meta‑analysis used CurraNZ's proprietary New Zealand blackcurrant extract, making this one of the most comprehensively researched polyphenol‑based supplements in sports and metabolic nutrition.
"Globally, there is huge demand for safe, natural ways to improve metabolic health and performance," added Dr Cook.
CurraNZ now stands as a benchmark for a natural ingredient with robust human evidence for enhancing fat burning during exercise — not through hype, but through hard data.
