Blackcurrant Supplementation Enhances Cognitive Performance in Resistance-Trained Individuals: A Randomized Placebo-Controlled Dose-Response Trial

Background: Blackcurrant (BC) supplementation has been shown to enhance cognitive performance. Studies indicate that BC can improve attention, mood, and cognitive function in healthy young adults. Additionally, BC consumption has been associated with increased alertness and reduced mental fatigue. Methods: Twenty resistance-trained individuals (7 males and 13 females; age: 21.5 ± 0.6 years, height: 167.9 ± 7.66 cm, weight: 73.9 ± 16.2 kg) took part in a randomized crossover study to assess the effects of BC supplementation. Participants were assigned to three conditions: a low-dose BC group (LBC: 250 mg/day BC combined with 350 mg/day maltodextrin), a high-dose BC group (HBC: 600 mg/day BC), and a placebo group (PL: 600 mg/day maltodextrin). Each supplementation phase spanned 7 days, followed by a 7-day washout period before transitioning to the next condition. Following each supplementation phase, participants completed the Stroop color-word test and assessed their readiness to perform using a visual analog scale. The data were evaluated using a two-way repeated measures analysis of variance (ANOVA) with Fisher's LSD tests applied for post hoc analysis ( p ≤ 0.05). Results: Participants completed the Stroop Word-Color test at baseline (BL) and after each treatment phase. In the Word section, a significant improvement was observed. Post hoc analysis indicated that both BC doses outperformed the BL scores but showed no significant difference compared to the PL. The mean scores were BL: 110.1 ± 17.8 counts, PL: 119.0 ± 12.2 counts, LD: 123.4 ± 13.8 counts, and HD: 119.1 ± 13.4 counts ( p = 0.002). In the Color section, scores following both BC doses were significantly higher than at BL, with the LD also outperforming the PL. The results were as follows: BL (79.3 ± 10.6 counts), PL (83.7 ± 11.7 counts), LD (90.0 ± 11.4 counts), and HD (84.8 ± 14.5 counts; p < 0.001). In the Word-Color section, the LD showed significantly higher scores compared to BL, while both BC doses outperformed the PL. The scores were as follows: BL (103.3 ± 19.9 counts), PL (105.1 ± 15.3 counts), LD (115.1 ± 15.4 counts), and HD (110.4 ± 16.7 counts; p = 0.007). When scores from all domains were combined, a significant overall improvement was observed. Post hoc analysis revealed that both BC dosages produced higher scores than BL, with the LD also surpassing the PL. The aggregated scores were BL (292.8 ± 44.5 counts), PL (307.9 ± 35.6 counts), LD (329.1 ± 34.4 counts), and HD (314.3 ± 39.9 counts; p < 0.001). No significant changes were observed in readiness ( p > 0.05). Conclusion: BC supplementation significantly enhanced cognitive performance in resistance-trained individuals. These findings suggest that BC supplementation may support attention, focus, and mental processing speed, especially at lower doses. However, no significant changes were observed in self-reported readiness to perform, indicating that BC's cognitive benefits may be independent of subjective perceptions of preparedness. The researchers fully funded this study themselves, ensuring its independence and reducing the risk of potential biases associated with external funding or grants. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.