In the August 21, 2002 issue of JAMA, researchers at Williams College in Williamstown, Massachusetts concluded that a 6-week study involving a daily dose of 120 mg ginkgo failed to provide any measurable cognitive benefit in elderly adults with healthy cognitive function. (1)

The American Herbal Products Association (AHPA) and the National Nutritional Foods Association (NNFA) strongly urge putting these results into perspective. Phil Harvey, Ph.D. and NNFA Director of Science and Quality Assurance/CSO, points out that other recent and well-designed studies have included people with normal mental function and have arrived at the opposite conclusion. Even the authors of the Williams College study concede that their study had possible limitations. The potential for a higher dose and/or a longer duration study to produce different results emphasizes the fact that conclusions should not be drawn at this time. (2)

One example of such a study that did demonstrate the positive results of Ginkgo in older adults with healthy cognitive function was published in the August 17, 2002 issue of Human Psychopharmacology. In this 6-week double-blind, placebo-controlled, randomized trial elderly volunteers took 180 mg of ginkgo extract per day. Overall, both objective and subjective evaluations indicated that ginkgo helped to support neuropsychological and memory processes in older adults with healthy cognitive function. (3)

Future investigations on the role of ginkgo in promoting cognitive function in adults with healthy mental capacity will continue to add to the understanding of this potentially promising application.

The AHPA's Vice President for Scientific and Technical Affairs, Steven Dentali, Ph.D., also urges individuals not to lose sight of the fact that for years, ginkgo has demonstrated the ability to support individuals with mild to moderate memory or concentration problems. (2) Mark Blumenthal, founder and executive director of the American Botanical Council (ABC), has made similar comments in pointing out that there are 125 clinical trials published on ginkgo extract spanning two decades and that the majority of these indicate support for circulation and mental function. (4)

In fact, the largest, most comprehensive review to date examining 33 clinical trials on the effects of ginkgo provides convincing evidence that it helps to support memory and cognitive function. The review acknowledges that some of the early trials were small, could have been controlled or conducted better, or subject to publication bias but that the totality of the evidence suggests support for healthy circulation, memory and mental acuity. Researchers hope to implement advanced methods and larger participant groups in future trials with ginkgo to further enhance the scientific integrity of this useful herb. (5)