Ginkgo biloba Extract and Preventing Alzheimer Disease
- Lon S. Schneider, MD
- Author Affiliation: Departments of Psychiatry and Behavioral Sciences, and Neurology, Keck School of Medicine, and the Leonard Davis School of Gerontology, University of Southern California, Los Angeles.
Since this article does not have an abstract, we have provided the first 150 words of the full text.
- KEYWORDS:
- ALZHEIMER DISEASE
- DEMENTIA
- DRUG THERAPY
- GINKGO BILOBA
- OUTCOME ASSESSMENT (HEALTH CARE)
- PLANT EXTRACTS
- STROKE
Ginkgo biloba leaves and extracts are widely used over-the-counter preparations marketed in the United States as food supplements or nutraceuticals, and as such, explicit health claims are not listed in their labeling. In other countries and in the popular press, G biloba is advocated for the treatment of a broad and seemingly ever-increasing range of medical conditions.
The extract used in the Ginkgo Evaluation of Memory (GEM) study reported in this issue of JAMA by DeKosky and colleagues1 and in many other clinical and preclinical studies is Ginkgo extract EGb 761 (Schwabe Pharmaceuticals, Karlsruhe, Germany). The extract is standardized to contain 2 major constituents: 22% to 27% flavonoids and 5% to 7% terpene lactones (ginkgolides and bilobalide).2 Unique to G biloba trees, the terpene lactones consist of several ginkgolides and bilobalide.2,3 The flavonoids and ginkgolides have protean biological activity in preclinical research. The flavonoids are …
