Ginkgo supplements not effective against Alzheimer's disease

A randomized clinical trial involving over 3000 elderly people in the US found that the popular herbal supplement Gingko biloba fared no better than placebo at preventing dementia or Alzheimer's disease.

The research was the work of the Ginkgo Evaluation of Memory (GEM) Study Investigators who are based at centers throughout the US, including the University of Pittsburgh, Pennsylvania, where lead author Dr Steven T DeKosky, was working at the time of the investigation. The findings are published in the 19 November issue of the Journal of the American Medical Association.

The randomized, placebo-controlled clinical trial included 3069 community-dwelling volunteers aged 75 and over and took place at five US medical research centers between 2000 and 2008. About half the volunteers were given a twice daily dose of 120mg extract of Ginkgo biloba and the other half took a placebo.

None of the participants showed signs more advanced than mild cognitive impairment at the start (2587 had normal cognition while 482 had mild cognitive impairment). They were followed for a median period of 6.1 years during which time they underwent 6-monthly assessments for dementia.