Ginkgo biloba in Alzheimer's disease: a systematic review.

This systematic review determines the benefit of treatment with Ginkgo biloba (Ginkgo) in Alzheimer's disease (AD) concerning patient-relevant outcomes. Bibliographic databases, clinical trial and study result registries were searched for randomized controlled trials (RCTs) in patients with AD (follow-up ≥16 weeks) comparing Ginkgo to placebo or a different treatment option. Manufacturers were asked to provide unpublished data. If feasible, data were pooled by meta-analysis. Six studies were eligible; overall, high heterogeneity was shown for most outcomes, except safety aspects. Among studies administering high-dose Ginkgo (240 mg), all studies favour treatment though effects remain heterogeneous. In this subgroup, a benefit of Ginkgo exists for activities of daily living. Cognition and accompanying psychopathological symptoms show an indication of a benefit. A harm of Ginkgo is not evident. An estimation of the effect size was not possible for any outcome. Further evidence is needed which focuses especially on subgroups of AD patients.