Abstract:
Background: Cocoa is a traditional plant-derived food with cultural, nutritional, and therapeutic relevance, particularly in regions where cacao has long been consumed as part of traditional dietary practices. Cocoa flavanols have gained increasing attention as natural bioactive compounds with potential effects on vascular function, brain perfusion, mental fatigue, and cognitive performance. These effects are especially relevant to the fields of traditional diets, cognitive nutrition, and clinical nutrition. However, the acute cognitive benefits of cocoa flavanol supplementation remain inconsistent, and the comparative efficacy of different flavanol doses has not been clearly established.
Objective: To evaluate the acute effects of cocoa flavanol supplementation on cognitive performance in healthy adults and to determine whether different flavanol doses demonstrate differential efficacy, particularly for attention-related outcomes.
Methods: A systematic review and meta-analysis of randomized controlled trials was conducted according to PRISMA guidelines and registered in PROSPERO (CRD420261386551). PubMed, Embase, and Cochrane Central were searched from inception to March 2026. Eligible studies included healthy adults aged 18–60 years receiving acute cocoa flavanol interventions. Attention outcomes were evaluated using network meta-analysis comparing low-dose cocoa flavanols (0–199 mg), medium-dose cocoa flavanols (200–599 mg), high-dose cocoa flavanols (≥600 mg), and control conditions. Pairwise random-effects meta-analyses were conducted for executive function, working memory, episodic memory, mental fatigue, and executive function under hypoxic conditions. Standardized mean differences (SMDs) or mean differences (MDs) with 95% confidence intervals (CIs) were calculated using restricted maximum likelihood estimation.
Results: Sixteen randomized controlled trials involving 624 participants were included. Acute cocoa flavanol supplementation significantly improved executive function (SMD −0.20; 95% CI: −0.36 to −0.03; p = 0.02) and reduced subjective mental fatigue (MD −4.82; 95% CI: −8.96 to −0.68; p = 0.023). No significant effects were observed for episodic memory (SMD 0.06; 95% CI: −0.40 to 0.53), working memory (SMD −0.07; 95% CI: −0.27 to 0.13), or executive function under hypoxic conditions (SMD 0.02; 95% CI: −0.40 to 0.44). Network meta-analysis showed no significant differences between cocoa flavanol dose categories and control conditions for attention performance.
Conclusion: Acute cocoa flavanol supplementation produced modest improvements in executive function and subjective mental fatigue in healthy adults but did not consistently enhance attention, memory, or executive function under hypoxic conditions. These findings suggest that cocoa flavanols may provide selective cognitive benefits rather than generalized cognitive enhancement. As a plant-derived compound rooted in traditional dietary practices, cocoa represents a promising intersection between Indigenous and traditional nutrition, mental health and cognitive nutrition, and therapeutic dietary strategies. Further studies are needed to clarify optimal dosing, mechanisms of action, and the clinical relevance of acute cocoa flavanol intake for cognitive health.
