At the end of the six years, the study's results indicated that 277 people who took ginkgo (18 percent) were diagnosed with dementia, compared with 246 (16 percent) in the placebo group. The ginkgo group also included 257 cases of Alzheimer's, versus 220 in the placebo group.
The researchers said the differences between the figures were not statistically significant. The scientists also compared the effects of the herb and the placebo in the areas of strokes, heart attacks and other cardiovascular events and found no statistical differences. Dementia and Alzheimer's afflict over 5.2 million people in the United States.
According to data from the Centers for Disease Control and Prevention, Alzheimer's surpassed diabetes two years ago as the sixth-leading cause of death in America. "No one is more disappointed that we didn't have any traction in slowing down the disease than the group that did the study," said Dr. Steven T. DeKosky, the neurologist who led the clinical trial, which was done for the National Center for Complementary and Alternative Medicine, a branch of the National Institutes of Health.
Mark Blumenthal, executive director of the American Botanical Council, a nonprofit group that supports herbal supplements, affirmed that the study incorporated in its pills the correct amount and kind of ginkgo extract, and gave it enough time to show an effect. But, he said, "let's keep in mind that to date, no conventional pharmaceutical drug has shown any benefit for either preventing the onset of Alzheimer's or dementia, or even slowing it down."