title: Effects of Ginkgo biloba on dementia: An overview of systematic reviews.
abstract: OBJECTIVE
  To assess the cumulative evidence on the efficacy and effectiveness of Ginkgo biloba extract (GbE) in the treatment of dementia.
  
  
  METHODS
  Overview of systematic reviews.
  
  
  METHODS
  PubMed/MEDLINE, EMBASE, Cochrane, and Google Scholar were searched in June 2016. Systematic reviews (SRs) of randomized controlled trials (RCTs) evaluating the effects of GbE on different outcomes in people with dementia or cognitive impairment were included. Methodological quality of the included SRs was assessed using the AMSTAR tool. The quality of evidence of the primary studies was assessed using GRADE.
  
  
  RESULTS
  Twelve SRs with meta-analyses met the eligibility criteria. The quality of the evidence reported in these SRs varies ranging from low to moderate level. Overall, the available evidence suggests that GbE has potentially beneficial effects over placebo on cognitive performance, activities of daily living, and clinical global impression in the treatment of dementia at doses greater than 200mg/day (usually 240mg/day) administrated for 22 weeks or longer, and that GbE appears to be safe for human consumption. No sufficient evidence supports the favorable effects of GbE administrated for less than 22 weeks. The available evidence consistently indicates that a dose less than 200mg/day of GbE may not be adequate to yield clinical relevant effects in the treatment of dementia.
  
  
  CONCLUSIONS
  GbE has potentially beneficial effects for people with dementia when it is administered at doses greater than 200mg/day for at least 5 months. Given the lower quality of the evidence, further rigorously-designed, multicenter-based, large-scale RCTs are warranted.
authors.affiliation: School of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China.
authors.forename: Qiuju
authors.initials: Q
authors.lastname: Yuan
authors.affiliation: Centre on Behavioral Health, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: Chong-Wen
authors.initials: CW
authors.lastname: Wang
authors.affiliation: Department of Integrated Traditional Chinese and Western Medicine, Liyuan Hospital, Tongji Medical College, Huazhong University of Science and Technology, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Shi
authors.affiliation: School of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China. Electronic address: linzx@cuhk.edu.hk.
authors.forename: Zhi-Xiu
authors.initials: ZX
authors.lastname: Lin
mesh_terms: D000203:Activities of Daily Living; D003071:Cognition / Q000187:drug effects*; D003704:Dementia / Q000175:diagnosis / Q000188:drug therapy* / Q000523:psychology; D004305:Dose-Response Relationship, Drug; D020441:Ginkgo biloba / Q000737:chemistry*; D006801:Humans; D018697:Nootropic Agents / Q000009:adverse effects / Q000302:isolation & purification / Q000627:therapeutic use*; D061214:Patient Safety; D008517:Phytotherapy; D010936:Plant Extracts / Q000009:adverse effects / Q000302:isolation & purification / Q000627:therapeutic use*; D010946:Plants, Medicinal; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D016896:Treatment Outcome; D000096983:Ginkgo Extract
chemical_list: D018697:Nootropic Agents; D010936:Plant Extracts; C063170:Ginkgo biloba extract; D000096983:Ginkgo Extract
keywords: Alzheimer's disease; Cognitive impairment; Dementia; Ginkgo biloba; Meta-analysis; Systematic review