Background: blackcurrant anthocyanins have been investigated for the effects on exercise-induced substrate utilisation. Studies have addressed the effects of dose, duration of intake and exercise modalities. Results are mixed, with studies generally demonstrating fat oxidation to be increased, while carbohydrate oxidation to be decreased.
Objective: to undertake a systematic review of literature and a meta-analysis of results.
Data sources: Electronic database searches were undertaken in PubMed, Web of Science and EBSCOhost from 1st May up to 14th November 2025, using a pre-defined search strategy.
Study selection: The inclusion criteria required studies to be controlled trials investigating the effects of blackcurrant supplementation on fat and carbohydrate oxidation during exercise in physically active adults (18-65 years). All forms, doses, and durations of blackcurrant supplementation were eligible, with outcomes reported as absolute rates of substrate utilisation during exercise.
Data extraction and synthesis: two authors independently extracted data and assessed for risk of bias using the Cochrane RoB 2 tool, with a random-effects meta-analysis undertaken on the mean difference between control or placebo and consumption of blackcurrant extract on exercise substrate utilisation.
Results: Searches returned 263 articles, with 15 studies included with 226 participants after full-text screening. Meta-analysis demonstrated blackcurrant extract to increase fat oxidation (0.042 g·min-1, P<0.001) and decrease carbohydrate oxidation (-0.099 g·min-1, P=0.012).
Conclusions: Blackcurrant can increase fat oxidation and decrease carbohydrate oxidation during exercise. However, this finding is not consistent for individuals and factors such as training status, sex, dosage, duration of intake may determine responses.