Ginkgo biloba is derived from the leaves of the ginkgo tree. It's been used in traditional Chinese medicine for thousands of years for various ailments.
Several studies suggest it improves mental function and protects nerves in some patients with Alzheimer's disease. This new study shows that ginkgo biloba may help people with multiple sclerosis.
A small, brief study "suggests that ginkgo biloba may be effective in improving attention in MS patients with cognitive dysfunction," write the researchers, who included Jesus Lovera, MD, of Oregon Health & Science University's neurology department.
However, ginkgo needs to be tested in much larger trials, says Lovera, in a news release.
"The study suggests that for cognitive problems, it may only help a certain group of patients," he says, adding that ginkgo's safety and efficacy also need to be examined. "We need to study this further."
The findings were presented in Miami Beach, Fla., at the American Academy of Neurology's 57th Annual Meeting.
A total of 39 people took part in the study. All had been diagnosed with MS and had some impairment in learning, memory, or speed of information processing.
First, participants took several tests on mental function skills. Then they were assigned to take a placebo or ginkgo biloba (120 milligrams twice daily) for three months. After that, they took the tests again.
The ginkgo group outperformed the placebo group on one -- but not all -- of the tests.
That task -- called the "Stroop test" -- had several steps. First, people were shown colored boxes and asked to name the color of each box. Next, they were instructed to read color names printed in ink of a different color (such as "green" written in red ink). The test takes advantage of our ability to read words more quickly and automatically than we can name colors.
Lastly, they described the ink used for each word.
The ginkgo group shaved four seconds off their time on the Stroop test, a 13% decrease compared with their performance prior to starting ginkgo. The placebo group's time remained unchanged.
Note for Supplement Takers
The researchers don't recommend or reject ginkgo. Their study was designed as an initial test, not the final word on the topic.
People considering any dietary or herbal supplements should do their homework and talk with their health care providers, says the National Center on Complementary and Alternative Medicine (NCCAM), a branch of the National Institutes of Health.
"Take charge of your health by being an informed consumer," says the NCCAM's web site. That's good advice with any type of medical treatment.