Cognitive Decline Not Slowed by Ginkgo Biloba

December 30, 2009

Newly published study results show that use of the herbal supplement for several years in patients age 72-96 did not result in a slower rate of cognitive decline than placebo.

"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. Indeed, in the United States and particularly in Europe, G biloba is perhaps the most widely used herbal treatment consumed specifically to prevent age-related cognitive decline," wrote the authors of newly published study results showing that use of the herbal supplement for several years in patients age 72-96 did not result in a slower rate of cognitive decline than placebo.

Beth E. Snitz, PhD, University of Pittsburgh, and colleagues found these results by analyzing outcomes from the Ginkgo Evaluation of Memory (GEM) study to see if the supplement slowed cognitive decline in those participants who had normal cognition or mild cognitive impairment at the start of the study. GEM—for which earlier results showed ginkgo biloba to not be effective in reducing incidence of Alzheimer’s dementia or overall dementia—was a randomized, double-blind, placebo-controlled trial of 3,069 participants who were given 120mg of the supplement or an identical-appearing placebo twice daily between 2000 and 2008, with a median follow-up of 6.1 years.

The current analysis found “no evidence for an effect of G biloba on global cognitive change and no evidence of effect on specific cognitive domains of memory, language, attention, visuospatial abilities and executive functions.”

The authors concluded that they found “no evidence that G biloba slows the rate of cognitive decline in older adults. These findings are consistent with previous smaller studies examining prevention of decline and facilitation of cognitive performance and with the 2009 Cochrane review of G biloba for dementia and cognitive impairment."