Ginkgo biloba did not prevent dementia or Alzheimer disease in elderly people.

QUESTION Does Ginkgo biloba reduce incident dementia and Alzheimer disease in elderly people with normal cognition or mild cognitive impairment? METHODS Design: randomised placebo controlled trial (Ginkgo Evaluation of Memory [GEM] study). ClinicalTrials.gov NCT00010803. Allocation: unclear allocation concealment.* Blinding: blinded (patients, clinicians, and outcome assessors).* Follow-up period: median 6.1 years. Setting: 5 academic medical centres in the USA. Participants: 3069 participants .75 years of age (mean age 79 y, 54% men) who had normal cognition or mild cognitive impairment (impaired at (10 th percentile of Cardiovascular Health Study normative data on 2 of 10 neuropsychological tests and Clinical Dementia Rating global score of 0.5). Intervention: Ginkgo biloba, 120 mg twice daily (n = 1545), or matching placebo (n = 1524). Outcomes: diagnosis of dementia and Alzheimer disease. Patient follow-up: 94% (intention-to-treat analysis). MAIN RESULTS Ginkgo biloba and placebo did not differ for incident dementia or Alzheimer disease (table). CONCLUSION Ginkgo biloba did not prevent incident dementia or Alzheimer disease in elderly people with normal cognition or mild cognitive impairment. Ginkgo biloba for prevention of dementia: a randomized controlled trial. Ginkgo biloba v placebo for preventing dementia in elderly people* At a median 6.1 years Outcomes Ginkgo biloba Placebo RRI (95% CI) NNH Dementia 18% 16% 11% (26 to 29) Not significant Alzheimer disease 17% 14% 15% (23 to 35) Not significant *Abbreviations defined in glossary. RRI, NNH, and CI calculated from control event rates and hazard ratios in article. COMMENTARY G inkgo biloba is a popular herbal supplement that is widely used in Europe and the USA for both treating and preventing dementia. However, good quality evidence supporting its effectiveness is lacking. In 2007, a Cochrane review of 35 clinical trials (n = 4247) suggested that Ginkgo biloba was ineffective for dementia. 1 The study by DeKosky et al shows that Ginkgo biloba is no more effective than placebo for preventing dementia. It addresses many weaknesses identified in previous studies by virtue of its large size (n = 3069) and relatively lengthy duration (>6 y exposure to Ginkgo biloba or placebo). People often consider herbal therapies to be safe, even if they are not effective, and although I have previously suggested that financial harm occurs if people spend money on ineffectual remedies, 2 this study suggests that physical harm may also occur. There was a non-significant increase in haemorrhagic strokes in the intervention group, and although this may be due …