DEC 01, 2008
A randomized, double-blind, placebo-controlled clinical trial has shown that use of the herb Ginkgo biloba-claimed to have beneficial effects on memory and cognition-was not effective in reducing the rate of dementia or Alzheimer's disease.
The study, conducted in five academic medical centers in the United States, enrolled more than 3,000 elderly participants aged 75 years or older with normal cognition (n = 2587) or mild cognitive impairment n = 482) at study entry. They were assessed every six months for incident dementia for a mean follow-up of six years. Participants were given 120 mg of Ginkgo biloba twice a day.
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, it is advocated for the treatment of a broad and seemingly ever-increasing range of medical conditions.