The CHS study leaders have looked at a number of factors that could be related to memory loss, such as high blood pressure and certain cholesterol factors.
Furberg, professor of public health sciences, said that beginning some time next year, the clinical trial would enroll participants at all four CHS sites.
While it is possible that enough CHS participants will enroll to meet the goal of 2,000 participants nationally, Furberg and Burke expect that the trial may need to be opened to as many as 500 outside participants -- 125 at each center.
The participants in the trial will be randomized to one of two arms: they will either get 240 milligrams of ginkgo daily, or an inert placebo that looks the same. The participants will be closely watched for any side effects. They'll return for clinic visits at one month, four months, and then every four months over the six-year course of the trial.
Furberg noted that the 240 milligrams is "an optimal and safe daily dose." Added Burke, "There will be an independent monitoring board that will evaluate to make sure that people consuming ginkgo are not at increased risk."
If ginkgo has a dramatic effect in preventing memory loss, the trial could be stopped early. "Then all the participants will be informed and will be advised that taking ginkgo may be a good thing for them to do," Burke said.
Among the issues that still need to be resolved before the trial can begin is the precise source of the ginkgo, and how the tablets can be standardized.
The clinical trial will cost about $15 million nationally. Of that, $3.7 million is budgeted for the Wake Forest clinical center and the clinical coordinating center.
Contact: Robert Conn, Mark Wright or Jim Steele
Wake Forest University Baptist Medical Center