What is Ginkgo Biloba?
Ginkgo biloba is a tree that is native to China and has been used in traditional Chinese medicine and cuisine for centuries. Extracts of Ginkgo biloba are often sold as food supplements with potential medicinal uses ranging from treating high blood pressure to altitude sickness.
The efficacy of Ginkgo extracts for the treatment of such conditions is not proven, although many people report beneficial effects. As Gingko Biloba is thought to be involved in blood flow regulation (being an antioxidant and having anti-inflammatory properties), many have speculated that it may be beneficial in dementia.
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What have studies shown?
Ginkgo biloba extract (EGb761) has been widely used to treat cognitive decline across Europe since 2000 as an alternative medicine, and used in some small scale clinical trials.
According to one recent systematic review, high dosages of EGb (240 mg/day) taken for at least 5 or 6 months may have beneficial effects on dementia sufferers compared to those taking 200 mg/day or less. Compared to placebo controls, those taking 240 mg/day of EGb761 had a slightly better recovery in terms of activities of daily living and overall cognitive performance.
Other studies have shown no overall beneficial effect of EGb on the treatment or prevention of Alzheimer’s disease. For example, the Ginkgo Evaluation of Memory (GEM) study found no significant beneficial effects of Gingko in reducing dementia or enhancing cognitive performance. This study included over 3000 participants; the largest of its kind. Furthermore, there were no differences between sex, ethnicity or baseline cognitive scores.
Can EGb761 prevent or treat Alzheimer’s disease?
Extensive analyses of the multiple studies performed to analyze the efficacy of EGb761 in the treatment of dementia have shown mixed results. Some show that high dosages may have moderately beneficial effects in slowing down cognitive decline, whereas others have shown no difference between those taking Gingko and those taking placebos.
In common with most alternative medicines, the majority of large-scale studies do not seem to show any significant effects of such medicines on the positive treatment of health conditions. When considering alternative medicines such as Gingko Biloba, patients and caregivers should not forgo conventional medicines and therapies in favor of alternative medicines whose efficacy is not proven.
However, a majority of herbal medicines do not cause any significant harm or side-effects, and may be used in conjunction with conventional medicines, providing the physician does not outline any specific harmful interactions e.g. warfarin and EGb761.
Summary
EGb761 may potentially have moderately beneficial effects in preventing or slowing down cognitive decline in Alzheimer’s disease. However, a majority of studies have not proved that it has significant positive effects in the treatment and prevention of dementia or cognitive decline, despite its wide usage. Using EGb761 in combination with conventional medicines may be beneficial, but relying on herbal medicines such as EGb761 alone is not recommended.
Further Reading
PET imaging and proteomics reveal distinct protein signatures in Alzheimer's disease progression