It was the largest study ever conducted on Ginkgo Biloba. And after 30 million dollars and seven years, researchers concluded the herbal supplement doesn't work.
They found no evidence that it staves off dementia and Alzheimer's, and also say it doesn't slow the progression of the disease.
More than three thousand volunteers over the age of 75 were followed for up to seven years, and the Journal of the American Medical Association found no difference between those who took the supplement and those who didn't.
Still, ginkgo biloba is one of the world's most popular supplements: and this study didn't look at other ways in which the supplement might improve brain health.
Right now, the doctors say the best advice for delaying the onset of dementia is free: stay active: there's evidence that an hour of walking a day works in keeping the mind sharp.