Blackcurrant Anthocyanin Supplementation alters Exercise-Induced Substrate Utilisation - A Systematic Review and Meta-analysis

Background: Blackcurrant anthocyanins have been investigated for their effects on exercise‑induced substrate utilisation. Previous research has examined the influence of supplementation dose, duration, and exercise modality, with mixed findings. Most studies report increased fat oxidation alongside reduced carbohydrate oxidation during exercise. Objective: to undertake a systematic review of literature and a meta-analysis of results. Data sources: Electronic searches were conducted in PubMed, Web of Science, and EBSCOhost between 1 May and 14 November 2025 using a predefined search strategy. Study selection: Controlled trials investigating the effects of blackcurrant supplementation on fat and carbohydrate oxidation during exercise in physically active adults (18–65 years) were included. All forms, doses, and supplementation durations were eligible, provided outcomes were 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. Registry: The review was registered 28th April 2025 in PROSPERO (CRD420251030222).