Ginkgo biloba is the top-selling herb in the United States. It has been used for a variety of medical conditions including asthma, deafness, and male impotence (68). It is predominantly used currently for the treatment of dementia, memory impairment, symptomatic peripheral vascular disease, and tinnitus. It is thought to have a number of biological effects including increasing blood flow, inhibiting platelet-activating factor, altering neuronal metabolism, and working as an antioxidant (69).
Its most promising use to date seems to be for the treatment of dementia. Mild improvements in cognitive performance and social functioning in patients with Alzheimer's and multi-infarct dementia were seen in one highly publicized trial that used the ginkgo extract Egb 761 (70). A systematic review of nine randomized, double-blind, placebo-controlled trials of ginkgo for the treatment of dementia similarly showed a mild but clinically significant effect in delaying cognitive decline (71).
The evidence for the use of ginkgo biloba for impaired memory (without dementia) is also positive but limited owing to the paucity of methodologically sound studies. A systematic review of clinical trials done for this indication suggested a significant benefit over placebo. However, the authors of this review were leery of making definitive conclusions owing to the possibility of publication bias (72). There is currently no evidence that ginkgo biloba is effective for the prevention of dementia or for memory enhancement in adults without impairment (73).
Given its suspected ability to increase blood flow, ginkgo has used for the treatment of intermittent claudication. A meta-analysis of eight randomized, double-blind, placebo-controlled clinical trials suggested that patients taking ginkgo significantly increased their pain-free walking distance compared to those taking placebo (74). This improvement seems to be similar to that seen with pentoxifylline but less effective than seen with walking exercises (75).
Owing to its effect on blood flow and fluidity, ginkgo has also been used for the treatment of tinnitus. Current evidence does not support its use for this indication (76). Limited preliminary evidence does exist for the use of ginkgo for the prevention of acute mountain sickness (77) and sudden deafness (78).
Side effects are usually rare and usually consist of gastrointestinal complaints or headaches. Cases of spontaneous bleeding (79) and seizures (80) have been reported. Owing to the possible potentiation of anticoagulant effects, ginkgo biloba use should be avoided in patients taking warfarin.
Was this article helpful?
Have you recently experienced hearing loss? Most probably you need hearing aids, but don't know much about them. To learn everything you need to know about hearing aids, read the eBook, Hearing Aids Inside Out. The book comprises 113 pages of excellent content utterly free of technical jargon, written in simple language, and in a flowing style that can easily be read and understood by all.