Herbal Brain Saver
WebMD News Archive
May 2, 2000 (San Diego, Calif.) -- Feeding mice the human equivalent of a
daily ginkgo biloba supplement reduces by a third the amount of brain damage
they experience following a stroke, researchers reported today at the
52nd annual meeting of the American Academy of Neurology. While
fellow researchers may have once laughed when lead investigator Wayne Clark,
MD, talked about using the popular herbal remedy to treat stroke, the positive
results from this study may lead to safety trials in humans.
"Our lab has looked at a variety of drugs being tested for stroke, and a
30% reduction [in the size of the stroke, as seen with ginkgo biloba] is as
good as any we've seen," says Clark, who is director of the Oregon Stroke
Center at Oregon Health Sciences University in Portland.
Any number of agents in ginkgo biloba might be responsible for its
protective effects, Clark says. He and his co-investigators have narrowed the
actions down to three -- it is an antioxidant, a blood thinner, and an
anti-inflammatory. One or all of these actions may be involved, he says, and
there may be others that are presently unknown.
The bad news is that too much ginkgo may be worse than none at all. Mice
given twice the amount that had proved beneficial had greater damage to their
brains than those that received inactive "placebo" tablets. The higher
dose of ginkgo may make the blood too thin, causing bleeding in the brain,
"We do not recommend that patients with stroke take [ginkgo] yet,"
Clark says. "I do not have any patient data to support this, but it's
probably relatively safe to take ginkgo if you're on aspirin [which also is a
blood thinner], and you want to take something for memory. But if you're on
coumadin or warfarin, I've been recommending not to take it."
- In a study of mice, supplements of ginkgo biloba reduced the amount of
brain damage following a stroke by 30%.
- Ginkgo acts as an antioxidant, a blood thinner, and an anti-inflammatory,
and researchers believe some or all of these properties may explain its effect
- Researchers are not yet recommending ginkgo for stroke patients and caution
that mice in the study who received too much ginkgo fared worse than those who
took inactive tablets.