Herbal supplement Ginkgo doesn't stop Alzheimer's
By Will Dunham
WASHINGTON (Reuters) - The widely used herbal supplement Ginkgo biloba does not appear to prevent Alzheimer's disease in healthy elderly people or those with mild cognitive impairment, U.S. researchers said on Tuesday.
The study involved 3,069 people age 75 or older at five U.S. locations who were tracked for six years on average, half taking twice-daily doses of 120 milligrams of extract from the leaves of the ginkgo tree and the rest taking a placebo.
Those who took the ginkgo were no more or less likely to develop Alzheimer's or any type of dementia, the researchers wrote in the Journal of the American Medical Association.
Dr. Steven DeKosky, dean of the University of Virginia School of Medicine who led the study, said he was disappointed in the results, citing early indications that ginkgo has antioxidant and other properties that might preserve memory.
"At this point in time, I wouldn't tell anybody to take the medication in hopes that it would work (to prevent Alzheimer's)," DeKosky, who was at the University of Pittsburgh when the study was conducted, said in a telephone interview.
"If they want to continue taking it -- because it's not toxic and not expensive -- they probably aren't going to hurt themselves other than spending the money," DeKosky added.
Ginkgo is one of the top-selling herbal supplements, used by people with the aim of improving memory and cognition and other purposes. This was the largest and most rigorous study to date on whether it would stave off Alzheimer's, experts said.
The people entered the study with either no cognitive problems or only mild impairment. Eighteen percent in the ginkgo group and 16 percent in the placebo group were diagnosed with Alzheimer's or other dementia during the study. Continued...