Saturday, December 18, 2010

Ginkgo Biloba Ineffective… Again

Ginkgo Biloba Many parents have cried “How many times do I have to tell you?” at their young children when trying to get their attention or emphasize specific behaviors. Now, pharmacists and other medical practitioners are beginning to feel like these parents: “How many times do we have to tell you that Ginkgo biloba is not all it’s cracked up to be?” Yet another study in the Journal of the American Medical Association (JAMA) reports that Gingko biloba is not effective in preventing cognitive decline in older adults, but people continue to take it in astounding numbers.
The study presents the results of the largest-scale clinical trial conducted with Ginkgo biloba, assessing more than 3000 adults aged 72 to 96 years. (The investigators have used the same population to investigate other aspects of Gingko treatment, with results published in several journals.) The current study focuses on the prevention of cognitive decline in older adults. The participants received a twice-daily dose of 120 mg of Ginkgo biloba or placebo. Over the 6-year follow-up period, the rate of decline of cognitive function, as assessed by standard cognitive and psychoneurological function exams, was calculated. Overall, there was no difference in the rate of cognitive decline between participants receiving Ginkgo biloba or placebo. These results did not change when modifying factors, such as age, sex, race, education, genetic variations, or baseline cognitive impairment, were considered.
This hardly seems like newsworthy information, given the plethora of studies that say the same thing. To date, there are no large-scale, definitive studies demonstrating that Ginkgo biloba has much of an effect on anything.  Most studies that do report benefits of Ginkgo biloba therapy are not comprehensive and obtained limited data regarding cognitive function. The results lend themselves to statistical misinterpretation and inappropriate extrapolation of the data.
Still, Ginkgo biloba sales are in the hundreds of millions of dollars worldwide every year. It is commonly used in European medicine to improve memory and treat neuronal disorders and improve brain metabolism. In the United States, it enjoys widespread use as a botanical dietary supplement. The current study should leave consumers asking, “Why?” Once again, Ginkgo biloba is verifiably ineffective for preventing a decline in cognitive function. Plus, as with many unregulated over-the-counter supplements, Ginkgo biloba places patients at increased risk for possible side effects and drug interactions.
Growing old gracefully and successfully is of paramount importance with an ever-older population. It is natural to strive for maintaining, and even enhancing, cognitive reserves. But, there is no evidence that proves Ginkgo biloba will help to achieve those goals. Clinicians and patients are better served by identifying and treating known conditions that may reduce brain capacity and cognitive function, including vascular risk factors, diabetes, and sleep disorders, and promote activities and lifestyles that build cognitive reserve.
… And we don’t want to have to tell you again!
References
Canis, M., Olzowy, B., Welz, C., Suckfüll, M., & Stelter, K. (2009). Simvastatin and Ginkgo biloba in the treatment of subacute tinnitus: a retrospective study of 94 patients American Journal of Otolaryngology DOI: 10.1016/j.amjoto.2009.09.004
Daffner KR. Promoting Successful Cognitive Aging: A Comprehensive Review. J Alzheimers Dis. Dec 14 2009.
Kaschel, R. (2009). Ginkgo biloba: specificity of neuropsychological improvement-a selective review in search of differential effects Human Psychopharmacology: Clinical and Experimental, 24 (5), 345-370 DOI: 10.1002/hup.1037
Leistner, E., & Drewke, C. (2010). Ginkgo biloba and Ginkgotoxin. Journal of Natural Products, 73 (1), 86-92 DOI: 10.1021/np9005019
Snitz, B., O’Meara, E., Carlson, M., Arnold, A., Ives, D., Rapp, S., Saxton, J., Lopez, O., Dunn, L., Sink, K., DeKosky, S., & , . (2009). Ginkgo biloba for Preventing Cognitive Decline in Older Adults: A Randomized Trial JAMA: The Journal of the American Medical Association, 302 (24), 2663-2670 DOI: 10.1001/jama.2009.1913

Jennifer Gibson, PharmD

Dr. Gibson is a practicing clinical pharmacist and freelance medical writer and editor with experience in researching and preparing scientific publications, developing public relations materials, creating educational resources and presentations, and editing technical manuscripts. Her clients include academic research institutions, international authors, pharmaceutical companies, professional organizations, and public advocacy groups.

8 Responses

  1. Diet in general can be important for mental health, but if you want to keep your cognitive abilities sharp you need to go out and use them – you have to challenge yourself, pursue puzzles, read books, learn new things, and pursue different hobbies.
    Everyone I know who is over 60 but still “sharp” does these kinds of things. They keep their brains active, and don’t just vegetate in front of the ‘tube.
  2. Evan says:
    What dosages have been used?
  3. What dosages have been used?
    The Ginkgo Evaluation of Memory (GEM) Study Investigators used twice-daily doses of 120-mg extract of Ginkgo biloba in their recent randomized trial.
    Sincerely,
    Shaheen
  4. Evan says:
    Thanks. It looks like it was a good trial.
  5. Yaacov says:
    First time I heard that ginko bilboa is ineffective I’ll tell my folks, They don’t read JAMA. It will take a lot of advertising to knock out the accepted perception.
  6. Charlie says:
    I would like to see some research into what Ginkgo biloba does do instead of what it doesn’t; it’s certainly not without activity. All this study indicates to me is that Ginkgo is ineffective for slowing cognitive decline in a normal, healthy, elderly population, but that is not all that it is indicated for. A Google Scholar search shows several promising findings in the first dozen hits.
  7. yvan says:
    it will take many test to prove whether gingko biloba is effective..but for now many of use believe that it is very effective espicially in brain functioning

kindly look for more details on the advertisements

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