"The clinical efficacy of the ginkgo biloba special extract EGb 761 in dementia of the Alzheimer type and multi-infarct dementia" was confirmed in a study published in the journal Pharmacopsychiatry. Another study, published in JAMA, similarly found that EGb 761 "was safe and appears capable of stabilizing and, in a substantial number of cases, improving the cognitive performance and the social functioning of demented patients for 6 months to 1 year. Researchers believe that Ginkgo improves cognitive function because it promotes good blood circulation in the brain and protects it from neuronal damage." This whole article can be found at the link below.

http://www.medicalnewstoday.com/articles/263105.php