2002-08-20 16:49:28 -0400
Hoping to give your memory or mental abilities a boost with ginkgo biloba? You may be disappointed by the results of study released Tuesday, which found no apparent memory-enhancing benefit for healthy people over 60.
"These data suggest that when taken following the manufacturer's instructions ginkgo provides no measurable benefit in memory or related cognitive function to adults with healthy cognitive function," according to the report in the August 21st issue of The Journal of the American Medical Association.
Ginkgo biloba is widely advertised to be helpful for a variety of conditions including memory loss and dementia. As a result many healthy people and those with mental decline have turned to the unregulated dietary supplement with the hopes of improving, or maintaining their mental abilities.
In the study, Dr. Paul R. Solomon of Williams College in Williamstown, Massachusetts and colleagues studied the effects of ginkgo on 98 men and 132 women over age 60. For 6 weeks, half the group took the manufacturer's recommended dose of the supplement and the other half took an inactive placebo.
All of the participants underwent a battery of tests designed to assess their mental abilities including memory before, during, and after the study period. Solomon's team also interviewed a close companion about the mental abilities of each of the men and women enrolled in the study.
Overall, 88% of the people completed the study, and the researchers found that "ginkgo did not facilitate performance on standard neuropsychological tests of learning, memory, attention, and concentration or naming and verbal fluency in elderly adults without cognitive impairment."
The study findings may not apply to different types of consumers taking other doses, the authors note.
"It is certainly possible that higher doses or longer periods of exposure than used in this study are necessary to detect changes; however, we administered the compound following the manufacturer's instructions," Solomon's team writes.
The dose used in the study was 120 milligrams per day, the same dose suggested by the German Commission E. More than 5 million prescriptions are written for ginkgo in Germany each year, mostly to treat dementia.
The researchers also did not measure the quality of the product, but note that the manufacturer says the product is "processed under strict guidelines...ensured through extensive quality control."
The authors note that ginkgo sales reached $240 million in the US in 1997, despite "the paucity of well-controlled" studies on its efficacy.
"In summary, this study does not support the manufacturer's claims of the benefits of ginkgo on learning and memory," they conclude.
SOURCE: The Journal of the American Medical Association 2002;288:835-840.
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