title: Ginseng for cognition.
abstract: BACKGROUND
  Ginseng is a herbal medicine in widespread use throughout the world. Its effect on the brain and nervous system has been investigated. It has been suggested, on the basis of both laboratory and clinical studies, that it may have beneficial effects on cognitive performance.
  
  
  OBJECTIVE
  To evaluate the efficacy and adverse effects of ginseng given to improve cognitive performance in healthy participants, participants with cognitive impairment or dementia.To highlight the quality and quantity of research evidence available.
  
  
  METHODS
  The Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (CDCIG), The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS, clinical trials registries and grey literature sources were searched on 24 February 2009 using the following terms: ginseng* OR panax OR ginsan OR "Jen Shen"OR shinseng OR Renshen OR schinseng OR ninjin OR gingilone OR panaxoside* OR ginsenoside* OR protopanaxa* OR protopanaxadiol OR protopanaxatriol OR panaxagin OR ginsenol OR ginsenine and terms for dementia and cognition. The CDCIG Specialized Register contains records from all major health care databases (The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS) as well as from many clinical trials registries and grey literature sources.
  
  
  METHODS
  All double-blind and single-blind randomized, placebo controlled trials assessing the effects of ginseng on cognitive function were eligible for inclusion. Interventions were considered to be ginseng if they were compounds containing ginseng or active agents of the Panax genus as the major component.
  
  
  METHODS
  Characteristics of each included trial were extracted independently by two reviewers using a self-developed data extraction form and entered into RevMan 5.0 software. Authors of identified trials were contacted for additional information and unpublished data. The effects of ginseng in healthy participants, participants with cognitive impairment or dementia were addressed independently.
  
  
  RESULTS
  Nine randomized, double-blind, placebo controlled trials meeting the inclusion criteria were identified. Eight trials enrolled healthy participants, and one was of subjects with age-associated memory impairment (AAMI).Only five of the identified trials had extractable information and were included in the analysis. Four studies investigated the effects of ginseng extract and one assessed the efficacy of ginseng compound HT008-1. All of these trials investigated the effects of ginseng on healthy participants. Pooling the data was impossible owing to heterogeneity in outcome measures, trial duration, and ginseng dosage. Results of the analysis suggested improvement of some aspects of cognitive function, behavior and quality of life. No serious adverse events associated with ginseng were found.
  
  
  CONCLUSIONS
  Currently, there is a lack of convincing evidence to show a cognitive enhancing effect of Panax ginseng in healthy participants and no high quality evidence about its efficacy in patients with dementia. Randomized, double-blind, placebo-controlled, parallel group trials with large sample sizes are needed to further investigate the effect of ginseng on cognition in different populations, including dementia patients.
authors.affiliation: Evidence-based Medicine Center, Medical School of Nantong University, 19 Qixiu Road, Nantong, Jiangsu, China, 226001.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Geng
authors.forename: Jiancheng
authors.initials: J
authors.lastname: Dong
authors.forename: Hengjian
authors.initials: H
authors.lastname: Ni
authors.forename: Myeong Soo
authors.initials: MS
authors.lastname: Lee
authors.forename: Taixiang
authors.initials: T
authors.lastname: Wu
authors.forename: Kui
authors.initials: K
authors.lastname: Jiang
authors.forename: Guohua
authors.initials: G
authors.lastname: Wang
authors.forename: Ai Ling
authors.initials: AL
authors.lastname: Zhou
authors.forename: Reem
authors.initials: R
authors.lastname: Malouf
mesh_terms: D000328:Adult; D003071:Cognition / Q000187:drug effects*; D003072:Cognition Disorders / Q000188:drug therapy*; D006801:Humans; D008875:Middle Aged; D018697:Nootropic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D005894:Panax / Q000009:adverse effects; D008517:Phytotherapy; D010936:Plant Extracts / Q000009:adverse effects / Q000627:therapeutic use; D016032:Randomized Controlled Trials as Topic
chemical_list: C533064:HT008-1; D018697:Nootropic Agents; D010936:Plant Extracts