Results from the Ginkgo Evaluation of Memory (GEM) Study were published today.

It was designed to determine if Ginkgo biloba is better than placebo in preventing dementia and Alzheimer’s disease in the elderly.

First, the details.

  • 3069 adults at least 75 years old were evaluated every 6 months over about 6 years for signs of dementia.
  • They were randomly assigned to take G. biloba 120 mg twice daily or placebo.
  • Neither the participants nor the researchers knew the treatment given — double-blind.

And, the results.

  • The rate of dementia was 3.3 per 100 person-years with G. biloba vs. 2.9 for placebo.
  • G. biloba also had no effect on the rate of progression to dementia in participants with mildly impaired reasoning.
  • Side effects were similar in both groups.

The bottom line?
The authors concluded, “G. biloba at 120 mg twice a day was not effective in reducing either the overall incidence rate of dementia or Alzheimer’s disease incidence in elderly individuals with normal cognition or those with mild cognitive impairment.

The dose used was based on past research that suggested it was effective. And the product used is reputable, according to the researchers, so it’s unlikely the results were due to poor quality medicine.

Would the results have been different if the study went on longer or if younger adults had been recruited? We don’t know. However, to learn more, the GEM researchers will continue to follow some of the participants using MRI to check for changes in brain function and structure.

A smaller study published earlier this year found that among 118 people there was no reduction in the risk of progression of cognitive (reasoning) impairment. Although, there was a significantly lower risk of progression and a smaller decline in memory scores among those who took all their doses of G. biloba.

11/18/08 19:37 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.