Cognitive Decline Not Slowed by Ginkgo Biloba

(December 30, 2009) - Taking Ginkgo biloba isn't likely to keep you from having memory problems as you age, according to a study in the Journal of the American Medical Association. Older adults who used the herbal supplement Ginkgo biloba for several years did not have a slower rate of cognitive decline compared to adults who received placebo. (Read about "Herbal Precautions")

"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 (Read about "Alzheimer's Disease")," the authors write. "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." However, evidence from large clinical trials regarding its effect on long-term cognitive functioning is lacking.

Researchers analyzed outcomes from the Ginkgo Evaluation of Memory (GEM) study to determine if G biloba slowed the rate of cognitive decline in older adults who had normal cognition or mild cognitive impairment (MCI) at the beginning of the study. The GEM study previously found that G biloba was not effective in reducing the incidence of Alzheimer dementia or dementia overall. (Read about "Dementia") The randomized, double-blind, placebo-controlled clinical trial included 3,069 participants, ages 72 to 96 years, who received a twice-daily dose of 120-mg extract of G biloba or identical-appearing placebo.

The researchers 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. They also found no evidence for differences in treatment effects by age, sex, race, education or baseline cognitive status.