Study Says Ginkgo Biloba Doesn't WorkDec 30, 2009 | Parker Waichman LLP
We have been writing for some time that none of the existing scientific evidence surrounding ginkgo biloba justifies the outrageous claims many manufacturers make about these supplements.
Many small studies to evaluate ginkgo biloba's mental benefits have been conducted with mixed results. Now, the largest and longest study of its kind to look into ginkgo biloba—the Ginkgo Evaluation of Memory study—found that the herb neither improves memory nor prevents a decline in cognition in the elderly, wrote USA Today. The study was funded by the National Center for Complementary and Alternative Medicine, a center of the National Institutes of Health, explained USA Today.
Ginkgo biloba is an herb from the ginkgo tree that has been used medicinally for thousands of years. Today, it is one of the top selling herbal supplements in the U.S. According to the Nutrition Business Journal, Americans spent $107 million on ginkgo biloba products last year. Over the past three decades a number of manufacturers have made claims that the herb improves memory, dementia, issues with cognition, and Alzheimer’s disease, said USA Today.
Ginkgo biloba supplement manufacturers have also claimed that the herb promotes blood circulation to the arms, legs and brain, which increases physical activity levels; can ease the symptoms of depression and anxiety, premenstrual syndrome, sexual problems, and other ailments; and can help treat intermittent claudication (a blood vessel disorder that causes pain in the legs when walking), Lyme Disease, heart disease, stroke, high cholesterol, high blood pressure, allergies, and chronic fatigue syndrome.
Steven DeKosky, dean of the University of Virginia School of Medicine and the study's senior author said the information about the herb is "disappointing news," adding that the only good news about gingko biloba from the study is that the herb seems to be safe, said USA Today. The study was a randomized, double-blind, placebo-controlled study that took place at six medical centers with over 3,000 people who between 72 and 96 years of age over seven years, said USA Today. The report appears in the current issue of the Journal of the American Medical Association (JAMA).
In November 2008, JAMA published early results of the study concluding that ginkgo biloba supplements did nothing to prevent or delay dementia or Alzheimer's disease. A little over half of the participants took 240 milligrams daily of the ginkgo extract EGb 761; the other participants took identical-looking placebos. Schwabe Pharmaceuticals, a large supplement maker in Germany, supplied all the pills. The subjects received either the supplement or the placebo twice daily for an average of more than six years. At the end of the study, no statistically significant difference in dementia or Alzheimer's rates was found between the groups. Of note, those who took ginkgo biloba were slightly more likely to be diagnosed with dementia and Alzheimer's.
The new research looked at the effect of ginkgo biloba extract on cognitive decline in seniors, with a focus on “memory, visual-spatial construction, language, attention, psychomotor speed, and executive function,” said USA Today. The research revealed no effect. "It just continues to show that in properly designed, placebo-controlled studies, we can't seem to find an effect for ginkgo biloba," said Lon Schneider, an Alzheimer's and gerontology expert at the University of Southern California, quoted USA Today. This study was, said Schneider, larger than all prior studies on the herb, combined.