Overall, in a pilot study of a ginkgo biloba extract for delaying the onset of dementia in the elderly, researchers did not find a reduction in progression to dementia in those using ginkgo versus those using placebo. However, when the researchers took into account participants' adherence to taking the compound, the group that took ginkgo did appear to have a reduced risk of progression and a smaller decline in memory.
This small study funded by the National Institute on Aging and NCCAM and led by Hiroko Dodge, Ph.D., and colleagues at the Oregon Health & Science University and the Oregon State University, followed 118 volunteers age 85 or older over the course of 42 months. The double-blind, randomized, and placebo-controlled study used 80 mg of ginkgo extract taken three times per day. The participants were tested on entering the trial for memory function and other measures of health and were seen every 6 months to assess changes. Overall, both groups had similar reports of adverse events; however, the ginkgo group had more incidences of stroke, but there were no deaths due to stroke.
The study focused on those 85+ years, as more than half of individuals with dementia in developed countries are in their 80s or are older, according to the authors. In addition, with an estimated 8 to 15 percent of those in the same age group progressing to dementia yearly, it is important to find safe treatments that can slow this process. The authors conclude that there are limitations to the study and the suggestive results of a possible benefit from ginkgo need to be confirmed by larger prevention clinical trials.