September 18, 2000
UW coordinates analysis of Ginkgo biloba study
Can the extract of the leaves of the Ginkgo biloba tree prevent or delay memory loss and personality changes associated with aging? Scientists at the University of Washington will analyze data being collected nationwide in a $15 million National Institutes of Health study of ginkgo.
The Ginkgo Evaluation of Memory Study (GEMS) is the first large-scale, scientifically based evaluation of Ginkgo biloba for the prevention of dementia. The five-year study will also investigate whether the substance can prevent cardiovascular problems, including stroke and atherosclerosis.
The study is funded by the National Center for Complementary and Alternative Medicine (NCCAM), in collaboration with the National Institute on Aging, the National Heart, Lung and Blood Institute, and the National Institute for Neurological Diseases and Stroke (all components of the National Institutes of Health).
Researchers hope to enroll a total of 3,000 seniors at four sites nationwide: Hagerstown, Md., Pittsburgh, Penn., Sacramento, Calif., and Winston-Salem, N.C. There are no clinical study centers in the Puget Sound area.
The Data Coordinating Center, which will compile and analyze information from the study, will be managed by scientists from the Department of Biostatistics in the UW School of Public Health and Community Medicine. Among the scientists who will be involved are the data center’s principal investigator, Dr. Richard A. Kronmal, a professor of biostatistics, and Annette Fitzpatrick, a research scientist.
“Due to the marketing of Ginkgo biloba, more and more individuals are taking these products without knowledge of their benefits — if any,” Fitzpatrick said. “We hope to document the effect of ginkgo not only on cognition, but on cardiovascular disease as well.”
As people age, changes in memory, thinking and personality can lead to significant impairment. Between one third and one half of the people over the age of 75 experience these changes, collectively referred to as dementia. The most serious form of dementia is Alzheimer’s disease, which affects about 4 million people in the United States. Such numbers are expected to grow more than three-fold as the population includes more and more elderly. An estimated 14 million baby boomers are at risk for developing Alzheimer’s in the next 20 to 30 years. There are no proven treatments for preventing or delaying the onset of dementia.
Ginkgo biloba has for thousands of years been heralded by the Chinese as having medicinal properties. While today it is widely prescribed by physicians in Europe to treat both vascular and cognitive disorders, in the United States it is not approved for medical use by the Food and Drug Administration. Nonetheless, consumers can readily buy products labeled as Ginkgo biloba that claim to improve memory, but there are no uniform standards required of manufacturers of herbal supplements. In fact, many products marketed as Ginkgo biloba may contain none of the substance. At present, there are no federal regulations to monitor the safety and marketing claims of this growing and lucrative nutritional supplement industry.
“If Ginkgo biloba extract is found effective, thousands of individuals at high risk for developing dementia will have an inexpensive and safe prevention option. However, if the extract is ineffective or unsafe, these data will provide important information to health consumers as they consider continued use of this herbal product,” said Dr. Richard L. Nahin, NCCAM director for extramural research, training and review.
Participants in the study will be placed randomly into one of two groups. Half will take 240 mg of Ginkgo biloba of defined purity; half will take a placebo (an inactive sugar pill). Each group will take two pills a day for up to five years. Neither the participants nor the researchers will know if the pills are Ginkgo biloba or a placebo while the trial is in progress.
