People are always looking for ways to improve their mental function. Ginkgo products have been widely promoted for improving improve memory and possibly delaying mental deterioration and are one of the largest category of supplements sold. A new study has looked at the impact of Gingko on the incidence of Alzheimer's and dementia in adults.
Ginkgo biloba extract did not lower the overall incidence of dementia or Alzheimer's disease amongst adults, age 75 or older, who were normal or had mild cognitive impairment when the study began. The trial, which is the largest and longest ever done to determine whether ginkgo can prevent mental deterioration, involved over 3,000 people who received either a ginkgo product or a placebo for a average of 6.1 years.
Additionally, the study's authors found more hemorrhagic strokes in the Ginkgo users, though the incidence was low and the difference was not statistically significant. Since it is well known that ginkgo has anticoagulant properties, this finding deserves further exploration and users should be cautioned.
[DeKosky S and others. Ginkgo biloba for prevention of dementia: A randomized controlled trial. JAMA 300:2253-2262, 2008] http://jama.ama-assn.org/cgi/content/abstract/300/19/2253
An accompanying editorial to the study stated:
"The . . . study adds to the substantial body of evidence that G biloba extract as it is generally used does not prevent dementia in individuals with or without cognitive impairment and is not effective for Alzheimer disease. . . . Users of this extract should not expect it to be helpful. Moreover, the potential adverse effects of G biloba extract illustrate why it is untenable to recommend a drug or nutraceutical in the absence of efficacy evidence simply because it could possibly help and initially appears harmless.
[Schneider LS. Ginkgo biloba extract and preventing Alzheimer disease." JAMA 300:2306-2308, 2008] http://jama.ama-assn.org/cgi/content/extract/300/19/2306
And there is another issue. One issue is, do these products work. Another is, do they really have in them what they say they do. Efficacy is one issue. Quality is another major issue. We looked at efficacy, not another resent report looked at quality.
Recently, ConsumerLab.com tested seven ginkgo products and found concern with the quality of the products they testes. Two of the products tested appeared to contain adulterated material, two of the products tested contained less ginkgo than claimed on their label, and one of the products tested that had less ginkgo, also was contaminated with lead and failed to break apart properly.
[Adulteration suspected with some memory supplements, ConsumerLab.com, Nov 18, 2008] http://www.consumerlab.com/index.asp?claffid=101024
These reports add to the evidence that taking it with the hope of improved mental function is a waste of money.