Ginkgo biloba, derived from the leaves of the Ginkgo biloba tree, is often touted as a memory aid. But it appears unlikely that ginkgo biloba can prevent memory loss associated with mild cognitive impairment or Alzheimer's disease.
Small, early studies showed modest improvements in cognitive function for older adults with dementia. However, the results of a large-scale study, published in a December 2009 issue of the Journal of the American Medical Association, found no evidence that ginkgo biloba prevents memory loss or slows the progression of cognitive decline in older adults. This was true for both those who had mild cognitive impairment at the start of the study and for those who didn't.
A single study rarely provides a complete picture of the benefits and risks of any herb or drug. However, in this case, ginkgo biloba doesn't appear to be living up to its earlier promise.