Vascular dementia is memory loss and difficulty communicating that is often caused by a series of small strokes in the brain. About one-fourth of people with dementia have stroke-induced dementia; most of the rest have Alzheimer's disease.
Chinese researchers gave 25 patients with mild-to-moderate stroke-induced vascular dementia a tablet containing an extract from Chinese ginseng roots and panax notoginseng. Panax notoginseng is a different herb but one that has chemical properties similar to ginseng, says Dr. Jinzhou Tian, lead author of the study.
"The effect we are seeing is actually from the both," says Tian, a professor in the department of care of the elderly at the Beijing University of Chinese Medicine.
Another 15 people with vascular dementia were given Duxil, the brand name for the drugs almitrine and raubasine, which have been shown to increase oxygen to brain tissue and are used to boost the memories in people with vascular dementia, Tian says.
Participants were given a series of memory tests at the outset of the study and after 12 weeks.
The patients in the group taking the ginseng showed a significant increase in their average score on five memory tests, including immediate and delayed story recall, delayed word recall, verbal learning and verbal recognition.
Their total memory score was significantly higher than for the group taking Duxil, though the scores for individual tests showed no statistically significant difference, Tian says.
"I would like to recommend doctors consider this herb for use in the treatment of dementia sufferers," he says.
Ginseng is a less expensive alternative to Duxil and other pharmaceuticals on the market, Tian adds.
He presented his research Feb. 14 at a meeting of the American Stroke Association in Phoenix.
But U.S. doctors caution that Tian's study was too small, and for too short a duration, to recommend ginseng to people with vascular dementia.
"It's premature to recommend it," says Dr. Robert Adams, chairman of the Stroke Council of the American Heart Association and a spokesman for the American Stroke Association. "For us to really become convinced, I think we need larger, randomized controlled trials."
Furthermore, the study design was somewhat unusual in that, instead of a placebo, the researchers compared ginseng to another drug, Adams says.
If you are going to take ginseng, be sure to tell your doctor. Many people have the misconception that herbs are harmless, Adams says. In fact, ginseng may be as potent as any drug and can interfere with other prescriptions, he says.
Side effects of too much ginseng include insomnia, dry mouth and constipation, Tian says. Chinese doctors typically recommend about 3 grams (2 grams of ginseng extract and 1 gram of panax notoginseng) taken in the morning.