by Jones P

Ginkgo Biloba Not Associated with Slower Decline in Cognitive Function

Cognitive decline is a loss in executive functioning (skills, thought processes, daily tasks, etc), language abilities, and memory. In the mild form, it may have very little impact on your day to day function, or it can be severe, as in Alzheimer's disease . Although it is most often associated with aging, it is not a normal part of the aging process. The exact cause of the decline is not well understood. Some treatments may help to temporarily slow the rate of decline, but there is no known cure.
The supplement ginkgo biloba is often promoted to help prevent cognitive decline. The Ginkgo Evaluation of Memory study (GEM) is a large study sponsored by the National Institutes of Health and the National Center for Complementary and Alternative Medicine. Researchers from the University of Pittsburgh analyzed outcomes from the GEM study to look for the effects of gingko biloba on the rate of cognitive decline.

About the Study

GEM is a randomized control trial with 3,069 participants. The participants were 72-96 years old with no cognitive impairment or mild cognitive impairment. The participants were randomly split into a treatment or control group and followed for 6.1 years. The treatment group received 120mg of ginkgo biloba, and the control group received a placebo twice a day; the researchers and participants were blinded to who had which treatment.
Cognitive levels were assessed at the beginning and end of the trial by a variety of tests and examinations including:
  • Modified Mini-Mental State Examination
  • Alzheimer Disease Assessment Scale
  • Neuropsychological test of memory, attention, visual-spatial construction, language, and executive functions
At the end of the trial period, there was no significant difference in the rate of cognitive decline between the participants in the control group and those in the treatment group.

How Does This Affect You?

Ginkgo biloba supplements are sold as a method to slow or prevent cognitive decline, but this study did not find that to be true in older adults. This study is considered a good quality study because it involved a large number of participants and took steps, such as blinding, to decrease the chances of unfairly influencing the outcome. There are many supplements and products that make various health claims. It is important to understand the harms and true benefits to avoid wasting your money or creating a harmful interaction with current medicine or treatment. It is best to discuss supplements with your doctor before taking or investing in them.
Cognitive decline with aging is a concern for many people. As the population of older adults grows, the prevention and treatment of cognitive decline will become more urgent. Additional research needs to be done to find better prevention techniques for this growing issue.


Alzheimer's Association
Ginkgo Evaluation of Memory Study
National Center for Complementary and Alternative Medicine


Snitz BE, O'meara ES, Carlson MC, et al. Ginkgo biloba for preventing cognitive decline in older adults: a randomized trial. JAMA . 2009 Dec 23/30;302(24):2663.

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