An herbal medicine used in Asia for 2,000 years can reduce the impact of dementia, a small study suggests.

After 16 people took the Chinese herbal preparation ba wei di huang wan (BDW) for 8 weeks, they showed a boost in mental functioning, and had less trouble doing their day-to-day activities. In contrast, people who took an inactive (placebo) pill experienced no improvements over the same time period.

“These results argue the benefits of BDW in the treatment of dementia,” the authors, led by Dr. Koh Iwasaki of Tohoku University School of Medicine in Miyagi, Japan, write.

The National Institute of Aging recommends that elderly people use caution when taking herbal treatments, since many can interfere with other medicines.

According to the Journal of the American Geriatrics Society report, BDW has been used for centuries by older adults throughout China, Japan and Korea. Evidence also suggests the herbal treatment may ease fatigue, cold sensation, and muscle weakness.

To investigate whether BDW helps improve the mental abilities of people with dementia, Iwasaki and colleagues asked 33 patients with mild to severe forms of the condition to try either the treatment or a placebo for 8 weeks. None of the patients, who were an average of 84 years old, were told which they were taking.

Participants had dementia for an average of 5 years. By the end of the study period, the authors noted that people who were given BDW showed a significant improvement in their mental functioning, and in their ability to complete day-to-day activities.

Even participants who showed minor improvements in mental functioning “became quick in their action and response to caregivers,” the authors write. “Nurses and families felt that the patients looked cheerful.”

People taking the placebo showed no significant improvement in either daily activities or mental functioning, the authors note.

None of the patients taking BDW experienced any side effects.

The reasons why BDW may improve dementia remain unclear, Iwasaki and his colleagues write. Some research suggests the treatment may boost the activity of important proteins in the brain, increase the amount of brain substances associated with learning and memory, or improve blood flow to the brain.

“A traditional Chinese medicine is not simply a purified substance but contains many ingredients, and the interaction of these ingredients is important,” the authors write. “Eight herbs in BDW were carefully devised to interlock according to the traditional rules.”

SOURCE: Journal of the American Geriatrics Society, September 2004.