Ginkgo against dementia: to prevent useless in therapy, the effect is still questionable
The German Society of Neurology (DGN) advises not to preventive taking ginkgo preparations against dementias. Also for the treatment of Alzheimer's disease is given for this substance is no general recommendation. Two new studies that investigated the benefits of the multi-million selling well in Germany Ginkgo extract against memory loss, had made in the public confusion: On the one hand brake preventive intake of the plant extract is not the decay of the brain. On the other hand, patients who are already suffering from Alzheimer's disease, may benefit from a high dosage (240 mg) of ginkgo extract.
Study 1: prevention in patients at an advanced age:
In the current American study [1] in the journal JAMA, the preparation of a German manufacturer with a dummy treatment (placebo) at 3069 seniors aged 75 years was compared. Most participants had been sane at baseline, at 482 people doctors, but a mild cognitive impairment (eng. Mild Cognitive Impairment, MCI) had diagnosed. This memory impairment is considered as a possible precursor of Alzheimer's disease. This Ginkgo Evaluation of Memory study (GEM) was co-funded by the US Institutes of Health (NIH) and was designed by the US National Center for Complementary and Alternative Medicine (NCCAM). The firm Schwabe had both in Germany and in the US over the counter Ginkgo biloba extract EGb 761 and the placebo pills provided, but was not involved in the design nor in the implementation or evaluation of the study.
The drug was given at the recommended dose of twice daily 120 milligrams and the subjects were followed for a median six years every six months for signs of dementia. During the study, diseased 523 participants, including 277 (17,9 percent) who received the Ginkgo extract and 246 (16,1 percent) who had received a placebo. These statistically insignificant differences led the study leader Dr. Steven T. DeKosky, dean of the Medical Faculty of the University of Virginia, to comment:
"If you are 70 center and this remedy will take for the prevention of dementia, I have to tell you. It does not affect"
In a statement the firm Schwabe [2] states that under the circumstances, an effect was not expected. Schwabe argues that the trial participants were on average 79 years old, but that start the damage to the nerve cells already about 15 20 to years before the onset of dementia.
Study 2: meta for the treatment of Alzheimer's disease:
Very recently, the Institute for Quality and Efficiency in Health Care (IQWiG) has published a report on Ginkgo biloba in Alzheimer's dementia published [3], which, however, the current American study has not yet been taken into account. In this report it came to a preexisting dementia - treat - especially the Alzheimer's type. "Patients with Alzheimer's disease may benefit from ginkgo-containing preparations, provided that they are taking this in a high dosage", puts it in the IQWiG report. This was demonstrated for the therapy goal "activities of daily living". In terms of mental abilities, general psychopathological concomitant symptoms and quality of life of the serving members there were at least indications of a benefit.
but IQWiG also refers to studies that showed no benefit of ginkgo biloba in Alzheimer's disease. Therefore is ultimately unclear how big the effect is, the 193-page final report, which was provided with many restrictions.
"We hold these valuation is too positive," says Professor Günther Deuschl, president of DGN. "Especially for the treatment of Alzheimer's disease are only some methodologically adequate studies. They show no consistent findings, so we can not give a general recommendation at the time." This also corresponds to the view of the regulatory authorities, as an authorization of Ginkgo biloba extracts specifically for Alzheimer's disease is not present.
Last year, a so-called meta-analysis of clinical trials 35 the Cochrane Collaboration on the effect of ginkgo extracts in thought disorders and dementia had come to the conclusion that there is only this "inconsistent and not convincing evidence" [4].
Sources:
[1] DeKosky ST, Ginkgo biloba for Prevention of Dementia, JAMA 2008; 300 (19): 2253-2262
. [2] Fa Schwabe Pharmaceuticals: Opinion on the US study ginkgo and dementia
[3] Institute for Quality and Efficiency in Health Care. Ginkgo compounds in Alzheimer's dementia. Final report A05-19B. Cologne: IQWiG; 2008
[4] Birks J, Grimley Evans J, Ginkgo biloba for cognitive impairment and dementia. Cochrane Database of Systematic Reviews 2007, 2 Issue. Art. No .: CD003120. DOI: 10.1002 / 14651858.CD003120.pub2
Source: Kiel [DGN]
