Cognitive and functional effects of Ginkgo biloba in neurodegenerative disorders: Systematic review and meta analysis

The incidence of neurodegenerative disorders is increasing globally, and although treatments exist, few are effective in slowing the rate of cognitive/functional decline associated with these conditions. The standardised Ginkgo biloba extract EGb-761 has been studied for possible neuroprotection, however the findings have varied significantly. This systematic review and meta-analysis examined the cognitive, functional and behavioural effects of EGb-761 in adults suffering from Alzheimer's disease, vascular dementia or mild cognitive impairment and evaluated the strength of evidence. PRISMA 2020 guidelines were followed for the preparation of this systematic review. The study was also registered at PROSPERO (CRD420251207465). Randomised and quasi-randomised controlled trials published between 2000-2025 were identified via a search of 5 major databases. A variety of cognitive, behavioural, and functional measures were analysed using standardised mean differences or mean differences with 95% confidence intervals. The I² statistic was used to determine the level of heterogeneity between studies. All statistical analyses were completed using Review Manager 5.4. Eighteen studies representing 7558 participants were included in the final analysis, 10 of which provided sufficient data for inclusion in a meta-analysis. While there were statistically insignificant changes in cognitive function, the pooled SMD of ADAS Cog was 0.03 with a 95% CI of -0.27 to 0.33, with high levels of heterogeneity ( I² = 80%). Similarly, the pooled MD of behavioural outcomes as measured by GERRI was 0.06 with a 95% CI of -0.07 to 0.20, showing no statistically significant difference. The pooled SMD of functional outcomes as measured by ADL was 0.02 with a 95% CI of -0.17 to 0.21, again showing no statistically significant difference, with low levels of heterogeneity ( I² = 7%). Ginkgo biloba extract had small and clinically meaningless effects on cognition, behaviour and functional ability. The quality of the evidence ranged from low to moderate, suggesting further large-scale, well-controlled studies are required to establish whether it may be useful in the treatment of neurodegenerative disorders.