Effects of natural extracts in cognitive function of healthy adults: a systematic review and network meta-analysis

Abstract

Background: For years, diets and natural extracts have been explored for boosting cognition, but limited evidence challenges their recommendation for widespread use. Objective: Our study aimed to perform a network meta-analysis to evaluate effects of natural extracts on cognitive function in healthy adults. Methods: Researchers reviewed randomized controlled trials from Embase, PubMed, Cochrane Library, and Web of Science (up to 7 September 2024). Study quality was assessed with the Cochrane Risk of Bias Tool, and node-splitting analysis ensured consistency (p > 0.05). SUCRA values were calculated using parametric bootstrapping with 10,000 resamples. Primary outcomes included global cognition, attention, memory, executive function, and cognitive flexibility, with efficacy ranked by SUCRA probabilities. Results: From 27 studies with 2,334 samples and 19 natural extract treatments, RPTW showed the greatest improvement in overall cognition (SUCRA: 95.9%). No extracts significantly outperformed placebo for attention. CG (Cistanche + Ginkgo biloba) was most effective for memory (SUCRA: 89.3%), executive function (SUCRA: 96.9%), and cognitive flexibility (SUCRA: 98.0%). Conclusion: RPTW extracts improve overall cognition in healthy adults, while CG enhances memory, executive function, and cognitive flexibility. Systematic Review Registration: https://inplasy.com/inplasy-2024-11-0007/, identifier INPLASY (INPLASY2024110007).