Longstanding claims that the herbal supplement ginko boloba helps to preserve cognitive health have been seriously disputed by a 6-year research project.  A coalition of professionals from universities across the U.S. collaborated on creating the report by conducting extensive, twice-yearly personal assessments of 3,000 subjects, aged 72 to 96, who took either ginko boloba or a placebo throughout the study. Many exhibited varying levels of cognitive deficiency.   

The herb is derived from the seeds of the Ginko, a unique species with no known relatives that originated in China and serves as the country’s official National Tree. Companies that distribute supplements containing the herb tout its supposed ability to preserve and sharpen cognitive functions without naming the neurological processes that create these reported benefits. The herb is prescribed as medication in Germany, and researchers used this pharmaceutical variety in their respective studies.

In summary, they found no correlation between the herb and the maintenance of overall cognitive health. At study’s end, subjects who’d been taking Ginko tablets scored no higher on cognitive assessments than those on a sugar-pill placebo, regardless of any pre-existing conditions like dementia or Alzheimer’s disease. They also failed to display any discernable symptomatic improvement relating to matters of memory, attention span, language, and general comprehension.

This is not the first study to note inconclusive or contradictory results in ginko testing. Some improvements in mood have been reported in other data sets, and no side effects are observed among those who take the herb in recommended daily doses. Still, ginko fails to provide the increased cognitive clarity that its makers promise. It may be safe, but it doesn't seem like much of a medication.