Gingko biloba: worthless
Interesting post by Steven Novella at Science-Based Medicine:
The National Center for Complementary and Alternative Medicine (NCCAM) is generally a waste of taxpayer money, but they have sponsored several well-designed large trials of popular herbal supplements. And one by one these studies have shown these popular products, such as echinacea for the common cold, to be ineffective.
To add to the list, published in JAMA this week are the results of the largest and longest trial to date of Gingko biloba for the improvement of cognitive function and to treat, prevent, or reduce the effects of Alzheimer’s disease or other dementia. The results of the study are completely negative.
The study was very rigorous – a consensus trial designed to address all the criticisms of prior smaller studies. It was a direct comparison of Gingko biloba at 120mg twice a day, double blind, randomized, multi-center trial involving 3019 subjects aged 72-96 for a median of 6.1 years. Subjects were followed with standardized tests of cognitive function.
The results are easy to report – every measure showed no difference between G biloba and placebo. There was no difference in cognitive function, risk of developing dementia, rate of progression of dementia or normal cognitive decline with aging. Usually such studies involve some random noise in the results, especially when several outcomes are measured. But with such a large study, random fluctuations should average out, and that is exactly what happened…