JAMA 2009;302 2663-2670
Ginkgo biloba for Preventing Cognitive Decline in Older Adults
A Randomized Trial
JAMA. 2009;302(24):2663-2670.
Context The herbal product Ginkgo biloba is taken frequentlywith the intention of improving cognitive health in aging. However,evidence from adequately powered clinical trials is lackingregarding its effect on long-term cognitive functioning.
Objective To determine whether G biloba slows the ratesof global or domain-specific cognitive decline in older adults.
Design, Setting, and Participants The Ginkgo Evaluationof Memory (GEM) study, a randomized, double-blind, placebo-controlledclinical trial of 3069 community-dwelling participants aged72 to 96 years, conducted in 6 academic medical centers in theUnited States between 2000 and 2008, with a median follow-upof 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 theModified Mini-Mental State Examination (3MSE), in the cognitivesubscale of the Alzheimer Disease Assessment Scale (ADAS-Cog),and in neuropsychological domains of memory, attention, visual-spatialconstruction, language, and executive functions, based on sumsof z scores of individual tests.
Results Annual rates of decline in z scores did not differbetween G biloba and placebo groups in any domains, includingmemory (0.043; 95% confidence interval [CI], 0.034-0.051 vs0.041; 95% CI, 0.032-0.050), attention (0.043; 95% CI, 0.037-0.050vs 0.048; 95% CI, 0.041-0.054), visuospatial abilities (0.107;95% CI, 0.097-0.117 vs 0.118; 95% CI, 0.108-0.128), language(0.045; 95% CI, 0.037-0.054 vs 0.041; 95% CI, 0.033-0.048),and executive functions (0.092; 95% CI, 0.086-0.099 vs 0.089;95% CI, 0.082-0.096). For the 3MSE and ADAS-Cog, rates of changevaried by baseline cognitive status (mild cognitive impairment),but there were no differences in rates of change between treatmentgroups (for 3MSE, P = .71; for ADAS-Cog, P = .97).There was no significant effect modification of treatment onrate of decline by age, sex, race, education, APOE*E4 allele,or baseline mild cognitive impairment (P> .05).
Conclusion Compared with placebo, the use of G biloba,120 mg twice daily, did not result in less cognitive declinein older adults with normal cognition or with mild cognitiveimpairment.
