Comprehensive Guide to Ginkgo Biloba
Ginkgo Biloba A Quick Guide
A large number of well-controlled clinical trials have established that Ginkgo Biloba extract is an effective intervention in the management of Age-related Cognitive Decline (ARCD) and other conditions involving memory loss. A review of this evidence was reported in Lancet in 1992, which noted that of 40 double-blind controlled trials evaluating the efficacy of Ginkgo Biloba Extract, eight of these trials were rated of good quality, involving a total patient population of 1,000 subjects. Seven of the eight studies showed very good results and the authors of the article indicated that the evidence was strong enough to conclude that Ginkgo Biloba Extract is an effective treatment for ARCD. Most studies reported since 1992 have supported this conclusion, both in people with Alzheimer’s disease and other patients with age-related memory impairment. 38 A placebo-controlled study published in the Journal of the American Medical Association in 1997, involving over 300 patients with Alzheimer’s disease, revealed that Ginkgo Biloba Extract significantly improved patient outcomes compared to the placebo group. This was the first North American study using Ginkgo Biloba, which has helped to establish Ginkgo as a credible intervention for Alzheimer’s patients and other cognitive-impaired subjects, in the mind of some members of the medical community. In this study, Ginkgo Biloba Extract taken at 40 mg, three times daily, was shown to stabilize a large number of Alzheimer’s patients, improving the cognitive performance and the social functioning of demented patients during a 6-month to one -year period. 30 A 1998 quantitative analytical review of ginkgo studies, published in the Archives of Neurology, reported that Ginkgo Biloba Extract exhibits a small, but significant effect within a 3 – 6 month treatment course, using 120 – 240 mg per day, on objective measurements of cognitive function in Alzheimer’s disease. According to this review, Ginkgo Biloba Extract has not shown any significant adverse side effects in formal trials, but there are two case reports of bleeding complications (e.g.,sub-dural hematoma) with the use of ginkgo.
2. Prevention of Memory Loss and Enhanced Memory in Healthy Subjects
Several recent studies have evaluated the ability of ginkgo to prevent age-related memory loss, and to enhance the memory of otherwise healthy young subjects. A 30 day double-blind placebo-controlled study, following 50 healthy men and women (18 – 40 years of age ), demonstrated that 120 mg per day of Ginkgo Biloba Extract resulted in significant improvement in some measures of memory function. A double-blind study of 26 subjects found that a single dose of 120 mg of Ginkgo Biloba Extract improved short-term memory, especially in people over 50 years of age. In a double-blind placebo-controlled crossover trial involving 20 individuals aged 19 – 24 years, a one time dose of Ginkgo Biloba Extract at 120, 240, or 360 mg resulted in improvement of mental-performance, most dramatically in one test that measured ability to rapidly perform attention-related tasks. A smaller trial involving eight subjects (25 – 40 years of age) found some improvement in short-term memory with a single dosing of Ginkgo Biloba Extract at 60 mg, but not at lower levels of intake. However, not all studies with younger patients have shown an improvement in memory function and larger, more long-term trials are required before Ginkgo can be recommended with confidence for this application.