Effects of Ginkgo biloba extract on cognitive function and blood pressure in elderly subjects

Abstract

In this randomized, double-masked study, we assessed the effects of a Ginkgo biloba (GB-8) extract on elderly volunteers with age-related cognitive dysfunction. A total of 260 subjects were tested to obtain a homogeneous group of 60 elderly subjects with mild-to-moderate cognitive impairment, as defined by a clinical rating scale. The subjects were allocated to one of three groups and received either GB-8 40 mg or 80 mg or placebo three times daily for 3 months. Before therapy was started and after 1 and 3 months of treatment, standardized testing of attention, concentration, and memory was performed. The subjects completed self-assessments before and after 3 months of therapy, and arterial blood pressure was measured at the same intervals. Clinical ratings were done before and after 3 months of treatment. Six subjects withdrew from the study, whereas 54 subjects (31 women and 23 men; mean age, 74 years; age range, 61 to 88 years) completed the study. After randomization, the groups were similar with respect to age, social class, level of education, and demographic characteristics. Objective test results showed that attention, concentration, and short-term verbal memory improved significantly in subjects receiving the low-dose (standard) treatment. Similar improvements were seen in the results of the self-assessment test and the clinical rating. Diastolic blood pressure decreased significantly during low-dose treatment. Treatment with the GB-8 extract was found to improve objective measures of cerebral function in elderly subjects with mild-to-moderate cognitive impairment; the improvement appeared to be clinically relevant. The possible antihypertensive action of Ginkgo biloba extract is sufficient to warrant further investigation