Ginkgo biloba is widely marketed as a supplement that can improve memory and cognition. Published studies either have not supported these claims or have been poorly designed. Solomon and associates conducted a randomized controlled trial to determine whether ginkgo has a beneficial effect in elderly, community-dwelling, cognitively intact patients.
Patients were included if they were older than 60 years, had not taken psychoactive medications within the previous 60 days, and had a companion who could provide information about the participant. Participants had a Mini-Mental State Examination score of at least 27 and did not have a history of psychiatric or neurologic disorders. Patients were randomized to receive either placebo or ginkgo (40 mg three times daily) for six weeks. The study was double-blinded. Before the study, participants completed neuropsychologic testing, including tests of memory, learning, attention, concentration, and expressive language. After the study, patients were contacted to determine their compliance and their subjective evaluation of their memory. Their companions completed a questionnaire about the frequency of memory lapses during the study.
There were 219 people evaluated at the end of the study (108 in the placebo group and 111 in the ginkgo group). At baseline, there were no differences between the groups in tests of learning, memory, naming, or verbal fluency. The patients in the placebo group did not self-report significantly different scores on the memory questionnaire than those in the ginkgo group.
The authors conclude that ginkgo biloba does not improve performance on a variety of cognitive tests nor does it subjectively improve memory in elderly patients. There is no benefit from using ginkgo biloba in cognitively intact elderly people.