In order to confirm the results of these studies, researchers conducted a 6-month study on 31 patients over the age of 50 with mild to moderate memory impairment. Patients were treated with either 40 mg of a standardized Ginkgo biloba extract three times per day or placebo (untreated). A variety of tests were performed at weeks 0, 12, and 24 to assess signs of cognitive impairment.
According to G. Rai and colleagues in Current Medical Research and Opinion, "The results in patients receiving Ginkgo biloba extract were found to be significantly superior to those of patients receiving placebo..."
Researchers concluded that "...Ginkgo biloba extract...has a beneficial effect on mental efficiency in elderly patients showing mild to moderate memory impairment of organic origin."
Curr Med Res Opin 1991;12(6):350-55.