The herb fares no better than placebos in preventing Alzheimer’s disease
The supplement Ginkgo biloba has failed to ward off Alzheimer’s disease or other forms of dementia any better than a placebo in a long-term trial, researchers report in the Nov. 19 Journal of the American Medical Association (JAMA).
“This is tremendously disappointing,” says study coauthor Steven DeKosky, a neurologist at the University of Virginia School of Medicine in Charlottesville.
DeKosky has good reason to feel let down. In earlier laboratory tests, ginkgo extract showed an ability to protect brain cells from the very sort of problems that occur in Alzheimer’s patients. In animal tests, the herb inhibited the clumping — or formation of plaques — of the protein amyloid-beta. These plaques are widely assumed to play a role in Alzheimer’s. Ginkgo also has antioxidant properties, further boosting its appeal.