Journal of the American Medical Association
Vol. 302 No. 24, December 23/30, 2009

A Randomized Trial
ABSTRACT
Context The herbal product Ginkgo biloba is taken frequently with the intention of improving cognitive health in aging. However, evidence from adequately powered clinical trials is lacking regarding its effect on long-term cognitive functioning.
Objective To determine whether G biloba slows the rates of global or domain-specific cognitive decline in older adults.
Design, Setting, and Participants The Ginkgo Evaluation of Memory (GEM) study, a randomized, double-blind, placebo-controlled clinical trial of 3069 community-dwelling participants aged 72 to 96 years, conducted in 6 academic medical centers in the United States between 2000 and 2008, with a median follow-up of 6.1 years.
Intervention Twice-daily dose of 120-mg extract of G biloba (n = 1545) or identical-appearing placebo (n = 1524).
Main Outcome Measures Rates of change over time in the Modified Mini-Mental State Examination (3MSE), in the cognitive subscale of the Alzheimer Disease Assessment Scale (ADAS-Cog), and in neuropsychological domains of memory, attention, visual-spatial construction, language, and executive functions, based on sums of z scores of individual tests.
Conclusion Compared with placebo, the use of G biloba, 120 mg twice daily, did not result in less cognitive decline in older adults with normal cognition or with mild cognitive impairment.
Trial Registration clinicaltrials.gov Identifier: NCT00010803
INTRODUCTION
Ginkgo biloba is marketed widely and used with the hope of improving, preventing, or delaying cognitive impairment associated with aging and neurodegenerative disorders such as Alzheimer disease. The primary outcome analysis from the Ginkgo Evaluation of Memory (GEM) study, the largest completed randomized, double-blind, placebo-controlled dementia prevention trial to date,1 found that G biloba, 120 mg twice daily, was not effective in reducing the incidence of Alzheimer dementia or dementia overall. Read the rest of this entry »